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Latorre A, Rocchi L, Paparella G, Manzo N, Bhatia KP, Rothwell JC. Changes in cerebellar output abnormally modulate cortical myoclonus sensorimotor hyperexcitability. Brain 2024; 147:1412-1422. [PMID: 37956080 PMCID: PMC10994547 DOI: 10.1093/brain/awad384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 10/07/2023] [Accepted: 11/02/2023] [Indexed: 11/15/2023] Open
Abstract
Cortical myoclonus is produced by abnormal neuronal discharges within the sensorimotor cortex, as demonstrated by electrophysiology. Our hypothesis is that the loss of cerebellar inhibitory control over the motor cortex, via cerebello-thalamo-cortical connections, could induce the increased sensorimotor cortical excitability that eventually causes cortical myoclonus. To explore this hypothesis, in the present study we applied anodal transcranial direct current stimulation over the cerebellum of patients affected by cortical myoclonus and healthy controls and assessed its effect on sensorimotor cortex excitability. We expected that anodal cerebellar transcranial direct current stimulation would increase the inhibitory cerebellar drive to the motor cortex and therefore reduce the sensorimotor cortex hyperexcitability observed in cortical myoclonus. Ten patients affected by cortical myoclonus of various aetiology and 10 aged-matched healthy control subjects were included in the study. All participants underwent somatosensory evoked potentials, long-latency reflexes and short-interval intracortical inhibition recording at baseline and immediately after 20 min session of cerebellar anodal transcranial direct current stimulation. In patients, myoclonus was recorded by the means of surface EMG before and after the cerebellar stimulation. Anodal cerebellar transcranial direct current stimulation did not change the above variables in healthy controls, while it significantly increased the amplitude of somatosensory evoked potential cortical components, long-latency reflexes and decreased short-interval intracortical inhibition in patients; alongside, a trend towards worsening of the myoclonus after the cerebellar stimulation was observed. Interestingly, when dividing patients in those with and without giant somatosensory evoked potentials, the increment of the somatosensory evoked potential cortical components was observed mainly in those with giant potentials. Our data showed that anodal cerebellar transcranial direct current stimulation facilitates-and does not inhibit-sensorimotor cortex excitability in cortical myoclonus syndromes. This paradoxical response might be due to an abnormal homeostatic plasticity within the sensorimotor cortex, driven by dysfunctional cerebello-thalamo-cortical input to the motor cortex. We suggest that the cerebellum is implicated in the pathophysiology of cortical myoclonus and that these results could open the way to new forms of treatment or treatment targets.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari 09042, Italy
| | - Giulia Paparella
- Department of Neurology, IRCCS Neuromed, Pozzilli, IS 86077, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
| | - Nicoletta Manzo
- Department of Neurology, IRCCS San Camillo Hospital, Venice 30126, Italy
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
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Mancuso M, Cruciani A, Sveva V, Casula E, Brown KE, Di Lazzaro V, Rothwell JC, Rocchi L. Changes in Cortical Activation by Transcranial Magnetic Stimulation Due to Coil Rotation Are Not Attributable to Cranial Muscle Activation. Brain Sci 2024; 14:332. [PMID: 38671984 PMCID: PMC11048461 DOI: 10.3390/brainsci14040332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
Transcranial magnetic stimulation coupled with electroencephalography (TMS-EEG) allows for the study of brain dynamics in health and disease. Cranial muscle activation can decrease the interpretability of TMS-EEG signals by masking genuine EEG responses and increasing the reliance on preprocessing methods but can be at least partly prevented by coil rotation coupled with the online monitoring of signals; however, the extent to which changing coil rotation may affect TMS-EEG signals is not fully understood. Our objective was to compare TMS-EEG data obtained with an optimal coil rotation to induce motor evoked potentials (M1standard) while rotating the coil to minimize cranial muscle activation (M1emg). TMS-evoked potentials (TEPs), TMS-related spectral perturbation (TRSP), and intertrial phase clustering (ITPC) were calculated in both conditions using two different preprocessing pipelines based on independent component analysis (ICA) or signal-space projection with source-informed reconstruction (SSP-SIR). Comparisons were performed with cluster-based correction. The concordance correlation coefficient was computed to measure the similarity between M1standard and M1emg TMS-EEG signals. TEPs, TRSP, and ITPC were significantly larger in M1standard than in M1emg conditions; a lower CCC than expected was also found. These results were similar across the preprocessing pipelines. While rotating the coil may be advantageous to reduce cranial muscle activation, it may result in changes in TMS-EEG signals; therefore, this solution should be tailored to the specific experimental context.
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Affiliation(s)
- Marco Mancuso
- Department of Human Neuroscience, University of Rome “Sapienza”, Viale dell’Università 30, 00185 Rome, Italy;
| | - Alessandro Cruciani
- Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo 21, 00128 Rome, Italy; (A.C.); (V.D.L.)
- Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo 200, 00128 Rome, Italy
| | - Valerio Sveva
- Department of Anatomical and Histological Sciences, Legal Medicine and Orthopedics, University of Rome “Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy;
| | - Elias Casula
- Department of System Medicine, “Tor Vergata” University of Rome, Via Montpellier 1, 00133 Rome, Italy;
| | - Katlyn E. Brown
- Department of Kinesiology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G5, Canada;
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo 21, 00128 Rome, Italy; (A.C.); (V.D.L.)
- Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo 200, 00128 Rome, Italy
| | - John C. Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK;
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK;
- Department of Medical Sciences and Public Health, University of Cagliari, Cittadella Universitaria di Monserrato, Blocco I S.S. 554 bivio per Sestu, Monserrato, 09042 Cagliari, Italy
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Hehl M, Van Malderen S, Geraerts M, Meesen RLJ, Rothwell JC, Swinnen SP, Cuypers K. Probing intrahemispheric interactions with a novel dual-site TMS setup. Clin Neurophysiol 2024; 158:180-195. [PMID: 38232610 DOI: 10.1016/j.clinph.2023.12.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/02/2023] [Accepted: 12/19/2023] [Indexed: 01/19/2024]
Abstract
OBJECTIVE Using dual-site transcranial magnetic stimulation (dsTMS), the effective connectivity between the primary motor cortex (M1) and adjacent brain areas such as the dorsal premotor cortex (PMd) can be investigated. However, stimulating two brain regions in close proximity (e.g., ±2.3 cm for intrahemispheric PMd-M1) is subject to considerable spatial restrictions that potentially can be overcome by combining two standard figure-of-eight coils in a novel dsTMS setup. METHODS After a technical evaluation of its induced electric fields, the dsTMS setup was tested in vivo (n = 23) by applying a short-interval intracortical inhibition (SICI) protocol. Additionally, the intrahemispheric PMd-M1 interaction was probed. E-field modelling was performed using SimNIBS. RESULTS The technical evaluation yielded no major alterations of the induced electric fields due to coil overlap. In vivo, the setup reliably elicited SICI. Investigating intrahemispheric PMd-M1 interactions was feasible (inter-stimulus interval 6 ms), resulting in modulation of M1 output. CONCLUSIONS The presented dsTMS setup provides a novel way to stimulate two adjacent brain regions with fewer technical and spatial limitations than previous attempts. SIGNIFICANCE This dsTMS setup enables more accurate and repeatable targeting of brain regions in close proximity and can facilitate innovation in the field of effective connectivity.
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Affiliation(s)
- Melina Hehl
- Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium; KU Leuven, Leuven Brain Institute (LBI), Leuven, Belgium; Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek, Belgium
| | - Shanti Van Malderen
- Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium; KU Leuven, Leuven Brain Institute (LBI), Leuven, Belgium; Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek, Belgium
| | - Marc Geraerts
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek, Belgium
| | - Raf L J Meesen
- Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium; Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek, Belgium
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, United Kingdom
| | - Stephan P Swinnen
- Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium; KU Leuven, Leuven Brain Institute (LBI), Leuven, Belgium
| | - Koen Cuypers
- Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium; KU Leuven, Leuven Brain Institute (LBI), Leuven, Belgium; Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek, Belgium.
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Ginatempo F, Loi N, Rothwell JC, Deriu F. Sensorimotor integration in cranial muscles tested by short- and long-latency afferent inhibition. Clin Neurophysiol 2024; 157:15-24. [PMID: 38016262 DOI: 10.1016/j.clinph.2023.10.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 10/19/2023] [Accepted: 10/27/2023] [Indexed: 11/30/2023]
Abstract
OBJECTIVE To compressively investigate sensorimotor integration in the cranial-cervical muscles in healthy adults. METHODS Short- (SAI) and long-latency afferent (LAI) inhibition were probed in the anterior digastric (AD), the depressor anguli oris (DAO) and upper trapezius (UT) muscles. A transcranial magnetic stimulation pulse over primary motor cortex was preceded by peripheral stimulation delivered to the trigeminal, facial and accessory nerves using interstimulus intervals of 15-25 ms and 100-200 ms for SAI and LAI respectively. RESULTS In the AD, both SAI and LAI were detected following trigeminal nerve stimulation, but not following facial nerve stimulation. In the DAO, SAI was observed only following trigeminal nerve stimulation, while LAI depended only on facial nerve stimulation, only at an intensity suprathreshold for the compound motor action potential (cMAP). In the UT we could only detect LAI following accessory nerve stimulation at an intensity suprathreshold for a cMAP. CONCLUSIONS The results suggest that integration of sensory inputs with motor output is profoundly influenced by the type of sensory afferent involved and by the functional role played by the target muscle. SIGNIFICANCE Data indicate the importance of taking into account the sensory receptors involved as well as the function of the target muscle when studying sensorimotor integration, both in physiological and neurological conditions.
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Affiliation(s)
- Francesca Ginatempo
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari, Italy
| | - Nicola Loi
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari, Italy
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
| | - Franca Deriu
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari, Italy; Unit of Endocrinology, Nutritional and Metabolic Disorders, AOU Sassari, Sassari, Italy.
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Mancuso M, Cruciani A, Sveva V, Casula EP, Brown K, Rothwell JC, Di Lazzaro V, Koch G, Rocchi L. Somatosensory input in the context of transcranial magnetic stimulation coupled with electroencephalography: An evidence-based overview. Neurosci Biobehav Rev 2023; 155:105434. [PMID: 37890602 DOI: 10.1016/j.neubiorev.2023.105434] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 10/11/2023] [Accepted: 10/22/2023] [Indexed: 10/29/2023]
Abstract
The transcranial evoked potential (TEP) is a powerful technique to investigate brain dynamics, but some methodological issues limit its interpretation. A possible contamination of the TEP by electroencephalographic (EEG) responses evoked by the somatosensory input generated by transcranial magnetic stimulation (TMS) has been postulated; nonetheless, a characterization of these responses is lacking. The aim of this work was to review current evidence about possible somatosensory evoked potentials (SEP) induced by sources of somatosensory input in the craniofacial region. Among these, only contraction of craniofacial muscle and stimulation of free cutaneous nerve endings may be able to induce EEG responses, but direct evidence is lacking due to experimental difficulties in isolating these inputs. Notably, EEG evoked activity in this context is represented by a N100/P200 complex, reflecting a saliency-related multimodal response, rather than specific activation of the primary somatosensory cortex. Strategies to minimize or remove these responses by EEG processing still yield uncertain results; therefore, data inspection is of paramount importance to judge a possible contamination of the TEP by multimodal potentials caused by somatosensory input.
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Affiliation(s)
- M Mancuso
- Department of Human Neurosciences, University of Rome "Sapienza", Viale dell'Università 30, 00185 Rome, Italy
| | - A Cruciani
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, 21, 00128 Rome, Italy; Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo 200, 00128 Rome, Italy
| | - V Sveva
- Department of Anatomical and Histological Sciences, Legal Medicine and Orthopedics, University of Rome "Sapienza", Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - E P Casula
- Department of System Medicine, "Tor Vergata" University of Rome, Via Montpellier 1, 00133 Rome, Italy
| | - K Brown
- Department of Kinesiology, University of Waterloo, 200 University Ave W, N2L 3G5 Waterloo, ON, Canada
| | - J C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG London, United Kingdom
| | - V Di Lazzaro
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology, and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, 21, 00128 Rome, Italy; Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo 200, 00128 Rome, Italy
| | - G Koch
- Non-Invasive Brain Stimulation Unit, IRCCS Santa Lucia Foundation, Via Ardeatina, 306/354, 00179 Rome, Italy
| | - L Rocchi
- Department of Medical Sciences and Public Health, University of Cagliari, Cittadella Universitaria di Monserrato Blocco I S.S, 554 bivio per Sestu 09042, Monserrato, Cagliari, Italy.
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Latorre A, Belvisi D, Rothwell JC, Bhatia KP, Rocchi L. Rethinking the neurophysiological concept of cortical myoclonus. Clin Neurophysiol 2023; 156:125-139. [PMID: 37948946 DOI: 10.1016/j.clinph.2023.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 09/04/2023] [Accepted: 10/13/2023] [Indexed: 11/12/2023]
Abstract
Cortical myoclonus is thought to result from abnormal electrical discharges arising in the sensorimotor cortex. Given the ease of recording of cortical discharges, electrophysiological features of cortical myoclonus have been better characterized than those of subcortical forms, and electrophysiological criteria for cortical myoclonus have been proposed. These include the presence of giant somatosensory evoked potentials, enhanced long-latency reflexes, electroencephalographic discharges time-locked to individual myoclonic jerks and significant cortico-muscular connectivity. Other features that are assumed to support the cortical origin of myoclonus are short-duration electromyographic bursts, the presence of both positive and negative myoclonus and cranial-caudal progression of the jerks. While these criteria are widely used in clinical practice and research settings, their application can be difficult in practice and, as a result, they are fulfilled only by a minority of patients. In this review we reappraise the evidence that led to the definition of the electrophysiological criteria of cortical myoclonus, highlighting possible methodological incongruencies and misconceptions. We believe that, at present, the diagnostic accuracy of cortical myoclonus can be increased only by combining observations from multiple tests, according to their pathophysiological rationale; nevertheless, larger studies are needed to standardise the methods, to resolve methodological issues, to establish the diagnostic criteria sensitivity and specificity and to develop further methods that might be useful to clarify the pathophysiology of myoclonus.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London, London, United Kingdom.
| | - Daniele Belvisi
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London, London, United Kingdom
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London, London, United Kingdom
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London, London, United Kingdom; Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
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Fong PY, Spampinato D, Michell K, Mancuso M, Brown K, Ibáñez J, Di Santo A, Latorre A, Bhatia K, Rothwell JC, Rocchi L. Reply to: "Reflecting the causes of variability of EEG responses elicited by cerebellar TMS". Neuroimage 2023; 281:120392. [PMID: 37769927 DOI: 10.1016/j.neuroimage.2023.120392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 09/25/2023] [Indexed: 10/01/2023] Open
Abstract
In their commentary on our recently published paper about electroencephalographic responses induced by cerebellar transcranial magnetic stimulation (Fong et al., 2023), Gassmann and colleagues (Gassmann et al., 2023b) try to explain the differences between our results and their own previous work on the same topic. We agree with them that many of the differences arise from our use of a different magnetic stimulation coil. However, two unresolved questions remain. (1) Which method is most likely to achieve optimal activation of cerebellar output? (2) To what extent are the evoked cerebellar responses contaminated by concomitant sensory input? We highlight the role of careful experimental design and of combining electrophysiological and behavioural data to obtain reliable TMS-EEG data.
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Affiliation(s)
- Po-Yu Fong
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Division of Movement Disorders, Department of Neurology and Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Medical School, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
| | - Danny Spampinato
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Non-Invasive Brain Stimulation Unit, IRCCS Santa Lucia Foundation, Via Ardeatina 306/354, Rome 00142, Italy
| | - Kevin Michell
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Marco Mancuso
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Katlyn Brown
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Jaime Ibáñez
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain; Department of Bioengineering, Imperial College, London, UK
| | - Alessandro Di Santo
- NEuroMuscular Omnicentre (NEMO), Serena Onlus, AOS Monaldi, Naples, Italy; Unit of Neurology, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Kailash Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
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Ginatempo F, Manzo N, Spampinato DA, Loi N, Burgio F, Rothwell JC, Deriu F. A Novel Paired Somatosensory-Cerebellar Stimulation Induces Plasticity on Cerebellar-Brain Connectivity. Cerebellum 2023:10.1007/s12311-023-01622-5. [PMID: 37897625 DOI: 10.1007/s12311-023-01622-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/17/2023] [Indexed: 10/30/2023]
Abstract
The cerebellum receives and integrates a large amount of sensory information that is important for motor coordination and learning. The aim of the present work was to investigate whether peripheral nerve and cerebellum paired associative stimulation (cPAS) could induce plasticity in both the cerebellum and the cortex. In a cross-over design, we delivered right median nerve electrical stimulation 25 or 10 ms before applying transcranial magnetic stimulation over the cerebellum. We assessed changes in motor evoked potentials (MEP), somatosensory evoked potentials (SEP), short-afferent inhibition (SAI), and cerebellum-brain inhibition (CBI) immediately, and 30 min after cPAS. Our results showed a significant reduction in CBI 30 minutes after cPAS, with no discernible changes in MEP, SEP, and SAI. Notably, cPAS10 did not produce any modulatory effects on these parameters. In summary, cPAS25 demonstrated the capacity to induce plasticity effects in the cerebellar cortex, leading to a reduction in CBI. This novel intervention may be used to modulate plasticity mechanisms and motor learning in healthy individuals and patients with neurological conditions.
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Affiliation(s)
- Francesca Ginatempo
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100, Sassari, Italy
| | | | - Danny A Spampinato
- Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Nicola Loi
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100, Sassari, Italy
| | | | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
| | - Franca Deriu
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100, Sassari, Italy.
- Unit of Endocrinology, Nutritional and Metabolic Disorders, AOU, Sassari, Sassari, Italy.
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Quattrone A, Latorre A, Magrinelli F, Mulroy E, Rajan R, Neo RJ, Quattrone A, Rothwell JC, Bhatia KP. A Reflection on Motor Overflow, Mirror Phenomena, Synkinesia and Entrainment. Mov Disord Clin Pract 2023; 10:1243-1252. [PMID: 37772299 PMCID: PMC10525069 DOI: 10.1002/mdc3.13798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/08/2023] [Accepted: 05/08/2023] [Indexed: 09/30/2023] Open
Abstract
In patients with movement disorders, voluntary movements can sometimes be accompanied by unintentional muscle contractions in other body regions. In this review, we discuss clinical and pathophysiological aspects of several motor phenomena including mirror movements, dystonic overflow, synkinesia, entrainment and mirror dystonia, focusing on their similarities and differences. These phenomena share some common clinical and pathophysiological features, which often leads to confusion in their definition. However, they differ in several aspects, such as the body part showing the undesired movement, the type of this movement (identical or not to the intentional movement), the underlying neurological condition, and the role of primary motor areas, descending pathways and inhibitory circuits involved, suggesting that these are distinct phenomena. We summarize the main features of these fascinating clinical signs aiming to improve the clinical recognition and standardize the terminology in research studies. We also suggest that the term "mirror dystonia" may be not appropriate to describe this peculiar phenomenon which may be closer to dystonic overflow rather than to the classical mirror movements.
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Affiliation(s)
- Andrea Quattrone
- Institute of NeurologyUniversity “Magna Graecia”CatanzaroItaly
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Francesca Magrinelli
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Eoin Mulroy
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Roopa Rajan
- Department of NeurologyAll India Institute of Medical Sciences (AIIMS)New DelhiIndia
| | - Ray Jen Neo
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
- Department of NeurologyHospital Kuala LumpurKuala LumpurMalaysia
| | - Aldo Quattrone
- Neuroscience Research Center, Department of Medical and Surgical SciencesUniversity “Magna Graecia”CatanzaroItaly
| | - John C. Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Kailash P. Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of NeurologyUniversity College LondonLondonUK
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Ibáñez J, Zicher B, Brown KE, Rocchi L, Casolo A, Del Vecchio A, Spampinato D, Vollette CA, Rothwell JC, Baker SN, Farina D. Standard intensities of transcranial alternating current stimulation over the motor cortex do not entrain corticospinal inputs to motor neurons. J Physiol 2023; 601:3187-3199. [PMID: 35776944 DOI: 10.1113/jp282983] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/22/2022] [Indexed: 11/08/2022] Open
Abstract
Transcranial alternating current stimulation (TACS) is commonly used to synchronize a cortical area and its outputs to the stimulus waveform, but gathering evidence for this based on brain recordings in humans is challenging. The corticospinal tract transmits beta oscillations (∼21 Hz) from the motor cortex to tonically contracted limb muscles linearly. Therefore, muscle activity may be used to measure the level of beta entrainment in the corticospinal tract due to TACS over the motor cortex. Here, we assessed whether TACS is able to modulate the neural inputs to muscles, which would provide indirect evidence for TACS-driven neural entrainment. In the first part of the study, we ran simulations of motor neuron (MN) pools receiving inputs from corticospinal neurons with different levels of beta entrainment. Results suggest that MNs are highly sensitive to changes in corticospinal beta activity. Then, we ran experiments on healthy human subjects (N = 10) in which TACS (at 1 mA) was delivered over the motor cortex at 21 Hz (beta stimulation), or at 7 Hz or 40 Hz (control conditions) while the abductor digiti minimi or the tibialis anterior muscle were tonically contracted. Muscle activity was measured using high-density electromyography, which allowed us to decompose the activity of pools of motor units innervating the muscles. By analysing motor unit pool activity, we observed that none of the TACS conditions could consistently alter the spectral contents of the common neural inputs received by the muscles. These results suggest that 1 mA TACS over the motor cortex given at beta frequencies does not entrain corticospinal activity. KEY POINTS: Transcranial alternating current stimulation (TACS) is commonly used to entrain the communication between brain regions. It is challenging to find direct evidence supporting TACS-driven neural entrainment due to the technical difficulties in recording brain activity during stimulation. Computational simulations of motor neuron pools receiving common inputs in the beta (∼21 Hz) band indicate that motor neurons are highly sensitive to corticospinal beta entrainment. Motor unit activity from human muscles does not support TACS-driven corticospinal entrainment.
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Affiliation(s)
- Jaime Ibáñez
- BSICoS group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
- Department of Bioengineering, Imperial College, London, UK
- Department for Clinical and movement neurosciences, Institute of Neurology, University College London, UK
| | - Blanka Zicher
- Department of Bioengineering, Imperial College, London, UK
| | - Katlyn E Brown
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Lorenzo Rocchi
- Department for Clinical and movement neurosciences, Institute of Neurology, University College London, UK
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Andrea Casolo
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Alessandro Del Vecchio
- Department of Artificial Intelligence in Biomedical Engineering, Faculty of Engineering, 17 Friedrich-Alexander University, Erlangen, Germany
| | - Danny Spampinato
- Non-Invasive Brain Stimulation Unit, Department of Behavioral and Clinical Neurology, Santa Lucia Foundation, Rome, Italy
| | | | | | - Stuart N Baker
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Dario Farina
- Department of Bioengineering, Imperial College, London, UK
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11
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Fong PY, Spampinato D, Michell K, Mancuso M, Brown K, Ibáñez J, Santo AD, Latorre A, Bhatia K, Rothwell JC, Rocchi L. EEG responses induced by cerebellar TMS at rest and during visuomotor adaptation. Neuroimage 2023; 275:120188. [PMID: 37230209 DOI: 10.1016/j.neuroimage.2023.120188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 05/17/2023] [Accepted: 05/22/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND Connections between the cerebellum and the cortex play a critical role in learning and executing complex behaviours. Dual-coil transcranial magnetic stimulation (TMS) can be used non-invasively to probe connectivity changes between the lateral cerebellum and motor cortex (M1) using the motor evoked potential as an outcome measure (cerebellar-brain inhibition, CBI). However, it gives no information about cerebellar connections to other parts of cortex. OBJECTIVES We used electroencephalography (EEG) to investigate whether it was possible to detect activity evoked in any areas of cortex by single-pulse TMS of the cerebellum (cerebellar TMS evoked potentials, cbTEPs). A second experiment tested if these responses were influenced by the performance of a cerebellar-dependent motor learning paradigm. METHODS In the first series of experiments, TMS was applied over either the right or left cerebellar cortex, and scalp EEG was recorded simultaneously. Control conditions that mimicked auditory and somatosensory inputs associated with cerebellar TMS were included to identify responses due to non-cerebellar sensory stimulation. We conducted a follow-up experiment that evaluated whether cbTEPs are behaviourally sensitive by assessing individuals before and after learning a visuomotor reach adaptation task. RESULTS A TMS pulse over the lateral cerebellum evoked EEG responses that could be distinguished from those caused by auditory and sensory artefacts. Significant positive (P80) and negative peaks (N110) over the contralateral frontal cerebral area were identified with a mirrored scalp distribution after left vs. right cerebellar stimulation. The P80 and N110 peaks were replicated in the cerebellar motor learning experiment and changed amplitude at different stages of learning. The change in amplitude of the P80 peak was associated with the degree of learning that individuals retained following adaptation. Due to overlap with sensory responses, the N110 should be interpreted with caution. CONCLUSIONS Cerebral potentials evoked by TMS of the lateral cerebellum provide a neurophysiological probe of cerebellar function that complements the existing CBI method. They may provide novel insight into mechanisms of visuomotor adaptation and other cognitive processes.
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Affiliation(s)
- Po-Yu Fong
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Division of Movement Disorders, Department of Neurology and Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan City, Taiwan; Medical School, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
| | - Danny Spampinato
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Non-invasive Brain Stimulation Unit, IRCCS Santa Lucia Foundation, Via Ardeatina 306/354, 00142, Rome, Italy
| | - Kevin Michell
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Marco Mancuso
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Katlyn Brown
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Jaime Ibáñez
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; BSICoS group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain; Department of Bioengineering, Imperial College, London, UK
| | - Alessandro Di Santo
- NEuroMuscular Omnicentre (NEMO), Serena Onlus, AOS Monaldi, Naples, Italy; Unit of Neurology, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Kailash Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
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12
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Martinez-Valdes E, Enoka RM, Holobar A, McGill K, Farina D, Besomi M, Hug F, Falla D, Carson RG, Clancy EA, Disselhorst-Klug C, van Dieën JH, Tucker K, Gandevia S, Lowery M, Søgaard K, Besier T, Merletti R, Kiernan MC, Rothwell JC, Perreault E, Hodges PW. Consensus for experimental design in electromyography (CEDE) project: Single motor unit matrix. J Electromyogr Kinesiol 2023; 68:102726. [PMID: 36571885 DOI: 10.1016/j.jelekin.2022.102726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/16/2022] [Accepted: 11/16/2022] [Indexed: 11/29/2022] Open
Abstract
The analysis of single motor unit (SMU) activity provides the foundation from which information about the neural strategies underlying the control of muscle force can be identified, due to the one-to-one association between the action potentials generated by an alpha motor neuron and those received by the innervated muscle fibers. Such a powerful assessment has been conventionally performed with invasive electrodes (i.e., intramuscular electromyography (EMG)), however, recent advances in signal processing techniques have enabled the identification of single motor unit (SMU) activity in high-density surface electromyography (HDsEMG) recordings. This matrix, developed by the Consensus for Experimental Design in Electromyography (CEDE) project, provides recommendations for the recording and analysis of SMU activity with both invasive (needle and fine-wire EMG) and non-invasive (HDsEMG) SMU identification methods, summarizing their advantages and disadvantages when used during different testing conditions. Recommendations for the analysis and reporting of discharge rate and peripheral (i.e., muscle fiber conduction velocity) SMU properties are also provided. The results of the Delphi process to reach consensus are contained in an appendix. This matrix is intended to help researchers to collect, report, and interpret SMU data in the context of both research and clinical applications.
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Affiliation(s)
- Eduardo Martinez-Valdes
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, UK
| | - Roger M Enoka
- Department of Integrative Physiology, University of Colorado Boulder, CO, USA
| | - Aleš Holobar
- Faculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, Maribor, Slovenia
| | | | - Dario Farina
- Department of Bioengineering, Imperial College London, London, UK
| | - Manuela Besomi
- School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - François Hug
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia; LAMHESS, Université Côte d'Azur, Nice, France; Institut Universitaire de France (IUF), Paris, France
| | - Deborah Falla
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, UK
| | - Richard G Carson
- Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Dublin, Ireland; School of Psychology, Queen's University Belfast, Belfast, UK; School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Australia
| | | | - Catherine Disselhorst-Klug
- Department of Rehabilitation and Prevention Engineering, Institute of Applied Medical Engineering, RWTH Aachen University, Aachen, Germany
| | - Jaap H van Dieën
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, the Netherlands
| | - Kylie Tucker
- School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Simon Gandevia
- Neuroscience Research Australia, University of New South Wales, Sydney, Australia
| | - Madeleine Lowery
- School of Electrical and Electronic Engineering, University College Dublin, Belfield, Dublin, Ireland
| | - Karen Søgaard
- Department of Clinical Research and Department of Sports Sciences and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Thor Besier
- Auckland Bioengineering Institute and Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - Roberto Merletti
- LISiN, Department of Electronics and Telecommunications, Politecnico di Torino, Torino, Italy
| | - Matthew C Kiernan
- Brain and Mind Centre, University of Sydney, Sydney, Australia Department of Neurology, Royal Prince Alfred Hospital, Sydney, Australia
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
| | - Eric Perreault
- Northwestern University, Evanston, IL, USA; Shirley Ryan AbilityLab, Chicago, IL, USA
| | - Paul W Hodges
- School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia.
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13
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Silvennoinen K, Säisänen L, Hyppönen J, Rissanen SM, Karjalainen PA, D'Ambrosio S, Jimenez‐Jimenez D, Zagaglia S, Rothwell JC, Balestrini S, Sisodiya SM, Julkunen P, Mervaala E, Kälviäinen R. Short- and long-interval intracortical inhibition in EPM1 is related to genotype. Epilepsia 2023; 64:208-217. [PMID: 36398398 PMCID: PMC10107775 DOI: 10.1111/epi.17466] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Progressive myoclonic epilepsy type 1 (EPM1) is caused by biallelic alterations in the CSTB gene, most commonly dodecamer repeat expansions. Although transcranial magnetic stimulation (TMS)-induced long-interval intracortical inhibition (LICI) was previously reported to be normal in EPM1, short-interval intracortical inhibition (SICI) was reduced. We explored the association between these measures and the clinical and genetic features in a separate group of patients with EPM1. METHODS TMS combined with electromyography was performed under neuronavigation. LICI was induced with an inter-stimulus interval (ISI) of 100 ms, and SICI with ISIs of 2 and 3 ms, and their means (mSICIs) were expressed as the ratio of conditioned to unconditioned stimuli. LICI and mSICI were compared between patients and controls. Nonparametric correlation was used to study the association between inhibition and parameters of clinical severity, including the Unified Myoclonus Rating Scale (UMRS); among patients with EPM1 due to biallelic expansion repeats, also the association with the number of repeats was assessed. RESULTS The study protocol was completed in 19 patients (15 with biallelic expansion repeats and 4 compound heterozygotes), and 7 healthy, age- and sex-matched control participants. Compared to controls, patients demonstrated significantly less SICI (median mSICI ratio 1.18 vs 0.38; p < .001). Neither LICI nor SICI was associated with parameters of clinical severity. In participants with biallelic repeat expansions, the number of repeats in the more affected allele (greater repeat number [GRN]) correlated with LICI (rho = 0.872; p < .001) and SICI (rho = 0.689; p = .006). SIGNIFICANCE Our results strengthen the finding of deranged γ-aminobutyric acid (GABA)ergic inhibition in EPM1. LICI and SICI may have use as markers of GABAergic impairment in future trials of disease-modifying treatment in this condition. Whether a higher number of expansion repeats leads to greater GABAergic impairment warrants further study.
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Affiliation(s)
- Katri Silvennoinen
- Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Chalfont Centre for EpilepsyUK
| | - Laura Säisänen
- Department of Clinical Neurophysiology, Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Jelena Hyppönen
- Department of Clinical Neurophysiology, Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
| | - Saara M. Rissanen
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | | | - Sasha D'Ambrosio
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Dipartimento di Scienze Biomediche e Cliniche "L. Sacco"Università degli Studi di MilanoMilanItaly
| | - Diego Jimenez‐Jimenez
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
| | - Sara Zagaglia
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
| | - John C. Rothwell
- Sobell Department of Motor Neuroscience and Movement DisordersUCL Queen Square Institute of NeurologyLondonUK
| | - Simona Balestrini
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Chalfont Centre for EpilepsyUK
- Neuroscience DepartmentMember of ERN EpiCARE, Meyer Children HospitalFlorenceItaly
| | - Sanjay M. Sisodiya
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Chalfont Centre for EpilepsyUK
| | - Petro Julkunen
- Department of Clinical Neurophysiology, Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Esa Mervaala
- Department of Clinical Neurophysiology, Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Institute of Clinical Medicine, School of Medicine, Faculty of Health SciencesUniversity of Eastern FinlandKuopioFinland
| | - Reetta Kälviäinen
- Kuopio Epilepsy Center, NeurocenterMember of ERN EpiCARE, Kuopio University HospitalKuopioFinland
- Institute of Clinical Medicine, School of Medicine, Faculty of Health SciencesUniversity of Eastern FinlandKuopioFinland
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14
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Ma K, Rothwell JC, Goetz SM. A revised calcium-dependent model of transcranial magnetic theta-burst stimulation. Clin Neurophysiol 2022; 144:41-49. [PMID: 36242947 DOI: 10.1016/j.clinph.2022.09.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/02/2022] [Accepted: 09/15/2022] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Calcium dependency is presently an essential assumption in modelling the neuromodulatory effects of transcranial magnetic stimulation. Y.Z.Huang et al.developed the first neuromodulation model to explain the bidirectional effects of theta-burst stimulation (TBS) based on the postsynaptic intracellular calcium concentration elevation. However, we discover that the published computer code is not consistent with the model formulation, neither do the parameters and derived plots consequently match the formulations. Here we intend to fix the computer code and re-calibrate the model. METHODS We corrected the affected difference equations and re-calibrated the revised model with experimental data using non-convex optimisation based on a L2 penalty. RESULTS The revised model outperforms the initial model in characterising the relative motor-evoked potential levels of TBS-induced after-effects in various conditions. CONCLUSIONS We corrected the inconsistencies in the previous model and computer code and provided a complete calibration to support the research that is based on it. SIGNIFICANCE This work improves the accuracy and secures the scope of the model, which is necessary to retain a rich body of research resulting from the model. Furthermore, this model provides both a quantitative model for several parameters of TBS and a basic model foundation for future refinement.
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Affiliation(s)
- Ke Ma
- Department of Engineering, School of Technology, University of Cambridge, Cambridge, United Kingdom.
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, United Kingdom
| | - Stephan M Goetz
- Department of Engineering, School of Technology, University of Cambridge, Cambridge, United Kingdom.
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15
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Li Z, Peterchev AV, Rothwell JC, Goetz SM. Detection of motor-evoked potentials below the noise floor: rethinking the motor stimulation threshold. J Neural Eng 2022; 19:10.1088/1741-2552/ac7dfc. [PMID: 35785762 PMCID: PMC10155352 DOI: 10.1088/1741-2552/ac7dfc] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 07/04/2022] [Indexed: 12/24/2022]
Abstract
Objective. Motor-evoked potentials (MEPs) are among the most prominent responses to brain stimulation, such as supra-threshold transcranial magnetic stimulation and electrical stimulation. Understanding of the neurophysiology and the determination of the lowest stimulation strength that evokes responses requires the detection of even smaller responses, e.g. from single motor units. However, available detection and quantization methods suffer from a large noise floor. This paper develops a detection method that extracts MEPs hidden below the noise floor. With this method, we aim to estimate excitatory activations of the corticospinal pathways well below the conventional detection level.Approach. The presented MEP detection method presents a self-learning matched-filter approach for improved robustness against noise. The filter is adaptively generated per subject through iterative learning. For responses that are reliably detected by conventional detection, the new approach is fully compatible with established peak-to-peak readings and provides the same results but extends the dynamic range below the conventional noise floor.Main results. In contrast to the conventional peak-to-peak measure, the proposed method increases the signal-to-noise ratio by more than a factor of 5. The first detectable responses appear to be substantially lower than the conventional threshold definition of 50µV median peak-to-peak amplitude.Significance. The proposed method shows that stimuli well below the conventional 50µV threshold definition can consistently and repeatably evoke muscular responses and thus activate excitable neuron populations in the brain. As a consequence, the input-output (IO) curve is extended at the lower end, and the noise cut-off is shifted. Importantly, the IO curve extends so far that the 50µV point turns out to be closer to the center of the logarithmic sigmoid curve rather than close to the first detectable responses. The underlying method is applicable to a wide range of evoked potentials and other biosignals, such as in electroencephalography.
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Affiliation(s)
- Zhongxi Li
- Department of Electrical & Computer Engineering, Duke University, Durham, USA
| | - Angel V. Peterchev
- Departments of Psychiatry & Behavioral Sciences, Neurosurgery, Biomedical Engineering, and Electrical & Computer Engineering, Duke University, Durham, USA
| | | | - Stefan M. Goetz
- (Corresponding author) Department of Engineering, University of Cambridge, Cambridge, UK () and Departments of Psychiatry & Behavioral Sciences, Neurosurgery, and Electrical & Computer Engineering, Duke University, Durham, USA ()
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16
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Casula EP, Leodori G, Ibáñez J, Benussi A, Rawji V, Tremblay S, Latorre A, Rothwell JC, Rocchi L. The Effect of Coil Orientation on the Stimulation of the Pre-Supplementary Motor Area: A Combined TMS and EEG Study. Brain Sci 2022; 12:brainsci12101358. [PMID: 36291292 PMCID: PMC9599651 DOI: 10.3390/brainsci12101358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 09/26/2022] [Accepted: 10/03/2022] [Indexed: 11/26/2022] Open
Abstract
Studies using transcranial magnetic stimulation (TMS) have demonstrated the importance of direction and intensity of the applied current when the primary motor cortex (M1) is targeted. By varying these, it is possible to stimulate different subsets of neural elements, as demonstrated by modulation of motor evoked potentials (MEPs) and motor behaviour. The latter involves premotor areas as well, and among them, the presupplementary motor area (pre–SMA) has recently received significant attention in the study of motor inhibition. It is possible that, similar to M1, different neuronal populations can be activated by varying the direction and intensity of TMS; however, the absence of a direct electrophysiological outcome has limited this investigation. The problem can be solved by quantifying direct cortical responses by means of combined TMS and electroencephalography (TMS–EEG). We investigated the effect of variable coil orientations (0°, 90°, 180° and 270°) and stimulation intensities (100%, 120% and 140% of resting motor threshold) on local mean field potential (LMFP), transcranial evoked potential (TEP) peaks and TMS–related spectral perturbation (TRSP) from pre–SMA stimulation. As a result, early and late LMFP and peaks were larger, with the coil handle pointing posteriorly (0°) and laterally (90°). This was true also for TRSP in the β–γ range, but, surprisingly, θ–α TRSP was larger with the coil pointing at 180°. A 90° orientation activated the right M1, as shown by MEPs elicitation, thus limiting the spatial specificity of the stimulation. These results suggest that coil orientation and stimulation intensity are critical when stimulating the pre–SMA.
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Affiliation(s)
- Elias P. Casula
- Non−Invasive Brain Stimulation Unit, IRCCS Santa Lucia Foundation, 00179 Rome, Italy
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Giorgio Leodori
- Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
- IRCCS Neuromed, 86077 Pozzilli, Italy
| | - Jaime Ibáñez
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
- Department of Bioengineering, Imperial College, London SW7 2AZ, UK
- BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, 50009 Zaragoza, Spain
| | - Alberto Benussi
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, 25121 Brescia, Italy
| | - Vishal Rawji
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Sara Tremblay
- The Royal’s Institute of Mental Health Research, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Département de Psychoéducation et Psychologie, Université du Québec en Outaouais, Gatineau, QC J8X 3X7, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - John C. Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
- Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy
- Correspondence:
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17
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Siebner HR, Funke K, Aberra AS, Antal A, Bestmann S, Chen R, Classen J, Davare M, Di Lazzaro V, Fox PT, Hallett M, Karabanov AN, Kesselheim J, Beck MM, Koch G, Liebetanz D, Meunier S, Miniussi C, Paulus W, Peterchev AV, Popa T, Ridding MC, Thielscher A, Ziemann U, Rothwell JC, Ugawa Y. Transcranial magnetic stimulation of the brain: What is stimulated? - A consensus and critical position paper. Clin Neurophysiol 2022; 140:59-97. [PMID: 35738037 PMCID: PMC9753778 DOI: 10.1016/j.clinph.2022.04.022] [Citation(s) in RCA: 98] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 03/14/2022] [Accepted: 04/15/2022] [Indexed: 12/11/2022]
Abstract
Transcranial (electro)magnetic stimulation (TMS) is currently the method of choice to non-invasively induce neural activity in the human brain. A single transcranial stimulus induces a time-varying electric field in the brain that may evoke action potentials in cortical neurons. The spatial relationship between the locally induced electric field and the stimulated neurons determines axonal depolarization. The induced electric field is influenced by the conductive properties of the tissue compartments and is strongest in the superficial parts of the targeted cortical gyri and underlying white matter. TMS likely targets axons of both excitatory and inhibitory neurons. The propensity of individual axons to fire an action potential in response to TMS depends on their geometry, myelination and spatial relation to the imposed electric field and the physiological state of the neuron. The latter is determined by its transsynaptic dendritic and somatic inputs, intrinsic membrane potential and firing rate. Modeling work suggests that the primary target of TMS is axonal terminals in the crown top and lip regions of cortical gyri. The induced electric field may additionally excite bends of myelinated axons in the juxtacortical white matter below the gyral crown. Neuronal excitation spreads ortho- and antidromically along the stimulated axons and causes secondary excitation of connected neuronal populations within local intracortical microcircuits in the target area. Axonal and transsynaptic spread of excitation also occurs along cortico-cortical and cortico-subcortical connections, impacting on neuronal activity in the targeted network. Both local and remote neural excitation depend critically on the functional state of the stimulated target area and network. TMS also causes substantial direct co-stimulation of the peripheral nervous system. Peripheral co-excitation propagates centrally in auditory and somatosensory networks, but also produces brain responses in other networks subserving multisensory integration, orienting or arousal. The complexity of the response to TMS warrants cautious interpretation of its physiological and behavioural consequences, and a deeper understanding of the mechanistic underpinnings of TMS will be critical for advancing it as a scientific and therapeutic tool.
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Affiliation(s)
- Hartwig R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark; Institute for Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Klaus Funke
- Department of Neurophysiology, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
| | - Aman S Aberra
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Andrea Antal
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Sven Bestmann
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom; Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Robert Chen
- Krembil Brain Institute, University Health Network and Division of Neurology, University of Toronto, Toronto, Ontario, Canada
| | - Joseph Classen
- Department of Neurology, University of Leipzig, Leipzig, Germany
| | - Marco Davare
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom; Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, via Álvaro del Portillo 21, 00128 Rome, Italy
| | - Peter T Fox
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Anke N Karabanov
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Nutrition and Exercise, University of Copenhagen, Copenhagen, Denmark
| | - Janine Kesselheim
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Mikkel M Beck
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Giacomo Koch
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy; Non-invasive Brain Stimulation Unit, Laboratorio di NeurologiaClinica e Comportamentale, Fondazione Santa Lucia IRCCS, Rome, Italy
| | - David Liebetanz
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Sabine Meunier
- Sorbonne Université, Faculté de Médecine, INSERM U 1127, CNRS 4 UMR 7225, Institut du Cerveau, F-75013, Paris, France
| | - Carlo Miniussi
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Italy; Cognitive Neuroscience Section, IRCCS Centro San Giovanni di DioFatebenefratelli, Brescia, Italy
| | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Angel V Peterchev
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Psychiatry & Behavioral Sciences, School of Medicine, Duke University, Durham, NC, USA; Department of Electrical & Computer Engineering, Duke University, Durham, NC, USA; Department of Neurosurgery, School of Medicine, Duke University, Durham, NC, USA
| | - Traian Popa
- Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland; Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL Valais), Clinique Romande de Réadaptation, Sion, Switzerland
| | - Michael C Ridding
- University of South Australia, IIMPACT in Health, Adelaide, Australia
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Ulf Ziemann
- Department of Neurology & Stroke, University Tübingen, Tübingen, Germany; Hertie Institute for Clinical Brain Research, University Tübingen, Tübingen, Germany
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Yoshikazu Ugawa
- Department of Neurology, Fukushima Medical University, Fukushima, Japan; Fukushima Global Medical Science Centre, Advanced Clinical Research Centre, Fukushima Medical University, Fukushima, Japan
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18
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Ginatempo F, Loi N, Manca A, Rothwell JC, Deriu F. Is it possible to compare inhibitory and excitatory intracortical circuits in face and hand primary motor cortex? J Physiol 2022; 600:3567-3583. [PMID: 35801987 PMCID: PMC9544430 DOI: 10.1113/jp283137] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 06/13/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract Face muscles are important in a variety of different functions, such as feeding, speech and communication of non‐verbal affective states, which require quite different patterns of activity from those of a typical hand muscle. We ask whether there are differences in their neurophysiological control that might reflect this. Fifteen healthy individuals were studied. Standard single‐ and paired‐pulse transcranial magnetic stimulation (TMS) methods were used to compare intracortical inhibitory (short interval intracortical inhibition (SICI); cortical silent period (CSP)) and excitatory circuitries (short interval intracortical facilitation (SICF)) in two typical muscles, the depressor anguli oris (DAO), a face muscle, and the first dorsal interosseous (FDI), a hand muscle. TMS threshold was higher in DAO than in FDI. Over a range of intensities, resting SICF was not different between DAO and FDI, while during muscle activation SICF was stronger in FDI than in DAO (P = 0.012). At rest, SICI was stronger in FDI than in DAO (P = 0.038) but during muscle contraction, SICI was weaker in FDI than in DAO (P = 0.034). We argue that although many of the difference in response to the TMS protocols could result from the difference in thresholds, some, such as the reduction of resting SICI in DAO, may reflect fundamental differences in the physiology of the two muscle groups.
![]() Key points Transcranial magnetic stimulation (TMS) single‐ and paired‐pulse protocols were used to investigate and compare the activity of facilitatory and inhibitory intracortical circuits in a face (depressor anguli oris; DAO) and hand (first dorsal interosseous; FDI) muscles. Several TMS intensities and interstimulus intervals were tested with the target muscles at rest and when voluntarily activated. At rest, intracortical inhibitory activity was stronger in FDI than in DAO. In contrast, during muscle contraction inhibitory activity was stronger in DAO than in FDI. As many previous reports have found, the motor evoked potential threshold was higher in DAO than in FDI. Although many of the differences in response to the TMS protocols could result from the difference in thresholds, some, such as the reduction of resting short interval intracortical inhibition in DAO, may reflect fundamental differences in the physiology of the two muscle groups.
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Affiliation(s)
- Francesca Ginatempo
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, Sassari, 07100, Italy
| | - Nicola Loi
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, Sassari, 07100, Italy
| | - Andrea Manca
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, Sassari, 07100, Italy
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
| | - Franca Deriu
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, Sassari, 07100, Italy.,Unit of Endocrinology, Nutritional and Metabolic Disorders, AOU Sassari, Sassari, Italy
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19
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Rothwell JC, Chen RS. Ying-Zu Huang, 1966-2021. Clin Neurophysiol 2022; 139:S1388-2457(22)00266-8. [PMID: 35599163 DOI: 10.1016/j.clinph.2022.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 05/02/2022] [Indexed: 11/03/2022]
Affiliation(s)
- John C Rothwell
- UCL Queen Square Institute of Neurology, London WC1E 6JW, UK
| | - Rou-Shayn Chen
- Department of Neurology, Chang Gung University College of Medicine, Taoyuan, Taiwan
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20
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Iannone A, Santiago I, Ajao ST, Brasil-Neto J, Rothwell JC, Spampinato DA. Comparing the effects of focal and conventional tDCS on motor skill learning: A proof of principle study. Neurosci Res 2022; 178:83-86. [PMID: 35123828 PMCID: PMC9042790 DOI: 10.1016/j.neures.2022.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 01/05/2022] [Accepted: 01/21/2022] [Indexed: 02/06/2023]
Abstract
Transcranial direct current stimulation (tDCS) has emerged as a promising intervention in clinical and behavioral neuroscience; however, the response variability to this technique has limited its impact, partly due to the widespread of current flow with conventional methods. Here, we investigate whether a more targeted, focal approach over the primary motor cortex (M1) is advantageous for motor learning and targeting specific neuronal populations. Our preliminary results show that focal stimulation leads to enhanced skill learning and differentially recruits distinct pathways to M1. This finding suggests that focal tDCS approaches may improve the outcomes of future studies aiming to enhance behavior.
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Affiliation(s)
- Aline Iannone
- Department of Clinical and Movement Neurosciences, University College London, London, UK; Department of Physiological Sciences, Biology Institute, University of Brasília, Brasília, DF, Brazil
| | - Irene Santiago
- Department of Clinical and Movement Neurosciences, University College London, London, UK; Department of Biomedicine, University of Sevilla, Sevilla, Spain
| | - Silvia T Ajao
- Department of Clinical and Movement Neurosciences, University College London, London, UK; Department of Psychological Sciences, University of Liverpool, Liverpool, UK
| | - Joaquim Brasil-Neto
- Department of Physiological Sciences, Biology Institute, University of Brasília, Brasília, DF, Brazil
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, University College London, London, UK
| | - Danny A Spampinato
- Department of Clinical and Movement Neurosciences, University College London, London, UK; Department of Clinical and Behavioural Neurology, IRCCS Santa Lucia Foundation, Rome, Italy.
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21
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Ginatempo F, Loi N, Rothwell JC, Deriu F. Corrigendum to "Physiological Differences in Hand and Face Areas of the Primary Motor Cortex in Skilled Wind and String Musicians" [Neuroscience 455 (2021) 141-150]. Neuroscience 2022; 490:315. [PMID: 35346638 DOI: 10.1016/j.neuroscience.2022.03.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | - Nicola Loi
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
| | - Franca Deriu
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
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22
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Sadnicka A, Rocchi L, Latorre A, Antelmi E, Teo J, Pareés I, Hoffland BS, Brock K, Kornysheva K, Edwards MJ, Bhatia KP, Rothwell JC. A Critical Investigation of Cerebellar Associative Learning in Isolated Dystonia. Mov Disord 2022; 37:1187-1192. [PMID: 35312111 PMCID: PMC9313805 DOI: 10.1002/mds.28967] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 01/20/2022] [Accepted: 01/24/2022] [Indexed: 12/31/2022] Open
Abstract
Background Objective Methods Results Conclusions
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Affiliation(s)
- Anna Sadnicka
- Department of Clinical and Movement Neurosciences University College London London UK
- Movement Disorders and Neuromodulation Group St. George's University of London London UK
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences University College London London UK
- Department of Medical Sciences and Public Health University of Cagliari Cagliari Italy
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences University College London London UK
| | - Elena Antelmi
- Department of Clinical and Movement Neurosciences University College London London UK
- Department of Neuroscience, Biomedicine and Movement University of Verona Verona Italy
| | - James Teo
- Department of Clinical and Movement Neurosciences University College London London UK
- Department of Neurosciences Kings College Hospital NHS Foundation Trust London UK
| | - Isabel Pareés
- Department of Clinical and Movement Neurosciences University College London London UK
- Movement Disorders Program, Neurology Department Hospital Ruber Internacional Madrid Spain
| | - Britt S. Hoffland
- Department of Clinical and Movement Neurosciences University College London London UK
- Department of Neurology Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center Nijmegen the Netherlands
| | - Kristian Brock
- Cancer Research UK Clinical Trials Unit University of Birmingham Birmingham UK
| | | | - Mark J. Edwards
- Department of Clinical and Movement Neurosciences University College London London UK
- Movement Disorders and Neuromodulation Group St. George's University of London London UK
| | - Kailash P. Bhatia
- Department of Clinical and Movement Neurosciences University College London London UK
| | - John C. Rothwell
- Department of Clinical and Movement Neurosciences University College London London UK
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23
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Leodori G, De Bartolo MI, Guerra A, Fabbrini A, Rocchi L, Latorre A, Paparella G, Belvisi D, Conte A, Bhatia KP, Rothwell JC, Berardelli A. Motor Cortical Network Excitability in Parkinson's Disease. Mov Disord 2022; 37:734-744. [PMID: 35001420 DOI: 10.1002/mds.28914] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Motor impairment in Parkinson's disease (PD) reflects changes in the basal ganglia-thalamocortical circuit converging on the primary motor cortex (M1) and supplementary motor area (SMA). Previous studies assessed M1 excitability in PD using transcranial magnetic stimulation (TMS)-evoked electromyographic activity. TMS-evoked electroencephalographic activity may unveil broader motor cortical network changes in PD. OBJECTIVE The aim was to assess motor cortical network excitability in PD. METHODS We compared TMS-evoked cortical potentials (TEPs) from M1 and the pre-SMA between 20 PD patients tested off and on medication and 19 healthy controls (HCs) and investigated possible correlations with bradykinesia. RESULTS Off PD patients compared to HCs had smaller P30 responses from the M1s contralateral (M1+) and ipsilateral (M1-) to the most bradykinetic side and increased pre-SMA N40. Dopaminergic therapy normalized the amplitude of M1+ and M1- P30 as well as pre-SMA N40. We found a positive correlation between M1+ P30 amplitude and bradykinesia in off PD patients. CONCLUSIONS Changes in M1 P30 and pre-SMA N40 in PD suggest that M1 excitability is reduced on both sides, whereas pre-SMA excitability is increased. The effect of dopaminergic therapy and the clinical correlation suggest that these cortical changes may reflect abnormal basal ganglia-thalamocortical activity. TMS electroencephalography provides novel insight into motor cortical network changes related to the pathophysiology of PD. © 2022 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Giorgio Leodori
- IRCCS Neuromed, Pozzilli, Italy.,Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | | | | | - Andrea Fabbrini
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom.,Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | | | - Daniele Belvisi
- IRCCS Neuromed, Pozzilli, Italy.,Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Antonella Conte
- IRCCS Neuromed, Pozzilli, Italy.,Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Alfredo Berardelli
- IRCCS Neuromed, Pozzilli, Italy.,Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
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24
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Hirschbichler ST, Rothwell JC, Manohar SG. Dopamine increases risky choice while D2 blockade shortens decision time. Exp Brain Res 2022; 240:3351-3360. [PMID: 36350356 PMCID: PMC9678996 DOI: 10.1007/s00221-022-06501-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022]
Abstract
Dopamine is crucially involved in decision-making and overstimulation within dopaminergic pathways can lead to impulsive behaviour, including a desire to take risks and reduced deliberation before acting. These behavioural changes are side effects of treatment with dopaminergic drugs in Parkinson disease, but their likelihood of occurrence is difficult to predict and may be influenced by the individual's baseline endogenous dopamine state, and indeed correlate with sensation-seeking personality traits. We here collected data on a standard gambling task in healthy volunteers given either placebo, 2.5 mg of the dopamine antagonist haloperidol or 100/25 mg of the dopamine precursor levodopa in a within-subject design. We found an increase in risky choices on levodopa. Choices were, however, made faster on haloperidol with no effect of levodopa on deliberation time. Shortened deliberation times on haloperidol occurred in low sensation-seekers only, suggesting a correlation between sensation-seeking personality trait and baseline dopamine levels. We hypothesise that levodopa increases risk-taking behaviour via overstimulation at both D1 and D2 receptor level, while a single low dose of haloperidol, as previously reported (Frank and O'Reilly 2006), may block D2 receptors pre- and post-synaptically and may paradoxically lead to higher striatal dopamine acting on remaining striatal D1 receptors, causing speedier decision without influencing risk tolerance. These effects could also fit with a recently proposed computational model of the basal ganglia (Moeller and Bogacz 2019; Moeller et al. 2021). Furthermore, our data suggest that the actual dopaminergic drug effect may be dependent on the individual's baseline dopamine state, which may influence our therapeutic decision as clinicians in the future.
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Affiliation(s)
- Stephanie T. Hirschbichler
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, WC1N 3BG UK ,Department of Neurology, University Hospital St. Pölten, Dunant-Platz 1, 3100 St. Pölten, Austria ,Karl Landsteiner University of Health Sciences, Dr. Karl-Dorrek-Straße 30, 3500 Krems, Austria
| | - John C. Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, WC1N 3BG UK
| | - Sanjay G. Manohar
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, WC1N 3BG UK ,Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, OX3 9DU UK
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25
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Manto M, Argyropoulos GPD, Bocci T, Celnik PA, Corben LA, Guidetti M, Koch G, Priori A, Rothwell JC, Sadnicka A, Spampinato D, Ugawa Y, Wessel MJ, Ferrucci R. Consensus Paper: Novel Directions and Next Steps of Non-invasive Brain Stimulation of the Cerebellum in Health and Disease. Cerebellum 2021; 21:1092-1122. [PMID: 34813040 DOI: 10.1007/s12311-021-01344-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/08/2021] [Indexed: 12/11/2022]
Abstract
The cerebellum is involved in multiple closed-loops circuitry which connect the cerebellar modules with the motor cortex, prefrontal, temporal, and parietal cortical areas, and contribute to motor control, cognitive processes, emotional processing, and behavior. Among them, the cerebello-thalamo-cortical pathway represents the anatomical substratum of cerebellum-motor cortex inhibition (CBI). However, the cerebellum is also connected with basal ganglia by disynaptic pathways, and cerebellar involvement in disorders commonly associated with basal ganglia dysfunction (e.g., Parkinson's disease and dystonia) has been suggested. Lately, cerebellar activity has been targeted by non-invasive brain stimulation (NIBS) techniques including transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) to indirectly affect and tune dysfunctional circuitry in the brain. Although the results are promising, several questions remain still unsolved. Here, a panel of experts from different specialties (neurophysiology, neurology, neurosurgery, neuropsychology) reviews the current results on cerebellar NIBS with the aim to derive the future steps and directions needed. We discuss the effects of TMS in the field of cerebellar neurophysiology, the potentials of cerebellar tDCS, the role of animal models in cerebellar NIBS applications, and the possible application of cerebellar NIBS in motor learning, stroke recovery, speech and language functions, neuropsychiatric and movement disorders.
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Affiliation(s)
- Mario Manto
- Service de Neurologie, CHU-Charleroi, 6000, Charleroi, Belgium.,Service Des Neurosciences, UMons, 7000, Mons, Belgium
| | - Georgios P D Argyropoulos
- Division of Psychology, Faculty of Natural Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Tommaso Bocci
- Aldo Ravelli Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142, Milan, Italy.,ASST Santi Paolo E Carlo, Via di Rudinì, 8, 20142, Milan, Italy
| | - Pablo A Celnik
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Louise A Corben
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, Department of Paediatrics, University of Melbourne, Parkville. Victoria, Australia
| | - Matteo Guidetti
- Aldo Ravelli Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142, Milan, Italy.,Department of Electronics, Information and Bioengineering, Politecnico Di Milano, 20133, Milan, Italy
| | - Giacomo Koch
- Fondazione Santa Lucia IRCCS, via Ardeatina 306, 00179, Rome, Italy
| | - Alberto Priori
- Aldo Ravelli Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142, Milan, Italy.,ASST Santi Paolo E Carlo, Via di Rudinì, 8, 20142, Milan, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Anna Sadnicka
- Motor Control and Movement Disorders Group, St George's University of London, London, UK.,Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Danny Spampinato
- Fondazione Santa Lucia IRCCS, via Ardeatina 306, 00179, Rome, Italy
| | - Yoshikazu Ugawa
- Department of Human Neurophysiology, Fukushima Medical University, Fukushima, Japan
| | - Maximilian J Wessel
- Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland.,Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL Valais), Clinique Romande de Réadaptation, Sion, Switzerland
| | - Roberta Ferrucci
- Aldo Ravelli Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142, Milan, Italy. .,ASST Santi Paolo E Carlo, Via di Rudinì, 8, 20142, Milan, Italy.
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26
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Fong PY, Spampinato D, Rocchi L, Hannah R, Teng Y, Di Santo A, Shoura M, Bhatia K, Rothwell JC. Two forms of short-interval intracortical inhibition in human motor cortex. Brain Stimul 2021; 14:1340-1352. [PMID: 34481097 PMCID: PMC8460995 DOI: 10.1016/j.brs.2021.08.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 08/21/2021] [Accepted: 08/31/2021] [Indexed: 11/24/2022] Open
Abstract
Background Pulses of transcranial magnetic stimulation (TMS) with a predominantly anterior-posterior (AP) or posterior-anterior (PA) current direction over the primary motor cortex appear to activate distinct excitatory inputs to corticospinal neurons. In contrast, very few reports have examined whether the inhibitory neurons responsible for short-interval intracortical inhibition (SICI) are sensitive to TMS current direction. Objectives To investigate whether SICI evaluated with AP and PA conditioning stimuli (CSPA and CSAP) activate different inhibitory pathways. SICI was always assessed using a PA-oriented test stimulus (TSPA). Methods Using two superimposed TMS coils, CSPA and CSAP were applied at interstimulus intervals (ISI) of 1–5 ms before a TSPA, and at a range of different intensities. Using a triple stimulation design, we then tested whether SICI at ISI of 3 ms using opposite directions of CS (SICICSPA3 and SICICSAP3) interacted differently with three other forms of inhibition, including SICI at ISI of 2 ms (SICICSPA2), cerebellum-motor cortex inhibition (CBI 5 ms) and short-latency afferent inhibition (SAI 22 ms). Finally, we compared the effect of tonic and phasic voluntary contraction on SICICSPA3 and SICICSAP3. Results CSAP produced little SICI at ISIs = 1 and 2 ms. However, at ISI = 3 ms, both CSAP and CSPA were equally effective at the same percent of maximum stimulator output. Despite this apparent similarity, combining SICICSPA3 or SICICSAP3 with other forms of inhibition led to quite different results: SICICSPA3 interacted in complex ways with CBI, SAI and SICICSPA2, whereas the effect of SICICSAP3 appeared to be quite independent of them. Although SICICSPA and SICICSAP were both reduced by the same amount during voluntary tonic contraction compared with rest, in a simple reaction time task SICICSAP was disinhibited much earlier following the imperative signal than SICICSPA. Conclusions SICICSPA appears to activate a different inhibitory pathway to that activated by SICICSAP. The difference is behaviourally relevant since the pathways are controlled differently during volitional contraction. The results may explain some previous pathological data and open the possibility of testing whether these pathways are differentially recruited in a range of tasks. Opposite directions of conditioning stimulus (CS) used to suppress MEPs evoked by a conventional test stimulus. Different directions of CS have different time courses of short-interval intracortical inhibition (SICI). They also interact differently with short-latency afferent inhibition and with cerebellar inhibition. They are differently affected in a reaction time task. We suggest there are two forms of SICI in motor cortex.
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Affiliation(s)
- Po-Yu Fong
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Division of Movement Disorders, Department of Neurology and Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan City, Taiwan; Medical School, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
| | - Danny Spampinato
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Non-invasive Brain Stimulation Unit, IRCCS Santa Lucia Foundation, Via Ardeatina 306/354, 00142, Rome, Italy
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Ricci Hannah
- Department of Psychology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Yinghui Teng
- Division of Biosciences, University College London, London, UK
| | - Alessandro Di Santo
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK; Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Mohamed Shoura
- Department of Neurology, Heliopolis and Al Azhar University Hospitals, Cairo, Egypt
| | - Kailash Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
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27
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Latorre A, Rocchi L, Batla A, Berardelli A, Rothwell JC, Bhatia KP. Reply to: "A Primary Writing Tremor Is a Form of Dystonic Tremor: Is the Debate Settled?". Mov Disord 2021; 36:1996-1997. [PMID: 34409688 DOI: 10.1002/mds.28695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 11/12/2022] Open
Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, United Kingdom
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, United Kingdom.,Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Amit Batla
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, United Kingdom
| | - Alfredo Berardelli
- Department of Human Neurosciences, University of Rome "Sapienza", Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, United Kingdom
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, United Kingdom
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28
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Vargas Luna JL, Brown J, Krenn MJ, McKay B, Mayr W, Rothwell JC, Dimitrijevic MR. Neurophysiology of epidurally evoked spinal cord reflexes in clinically motor-complete posttraumatic spinal cord injury. Exp Brain Res 2021; 239:2605-2620. [PMID: 34213632 PMCID: PMC8354937 DOI: 10.1007/s00221-021-06153-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 06/13/2021] [Indexed: 11/24/2022]
Abstract
Increased use of epidural Spinal Cord Stimulation (eSCS) for the rehabilitation of spinal cord injury (SCI) has highlighted the need for a greater understanding of the properties of reflex circuits in the isolated spinal cord, particularly in response to repetitive stimulation. Here, we investigate the frequency-dependence of modulation of short- and long-latency EMG responses of lower limb muscles in patients with SCI at rest. Single stimuli could evoke short-latency responses as well as long-latency (likely polysynaptic) responses. The short-latency component was enhanced at low frequencies and declined at higher rates. In all muscles, the effects of eSCS were more complex if polysynaptic activity was elicited, making the motor output become an active process expressed either as suppression, tonic or rhythmical activity. The polysynaptic activity threshold is not constant and might vary with different stimulation frequencies, which speaks for its temporal dependency. Polysynaptic components can be observed as direct responses, neuromodulation of monosynaptic responses or driving the muscle activity by themselves, depending on the frequency level. We suggest that the presence of polysynaptic activity could be a potential predictor for appropriate stimulation conditions. This work studies the complex behaviour of spinal circuits deprived of voluntary motor control from the brain and in the absence of any other inputs. This is done by describing the monosynaptic responses, polysynaptic activity, and its interaction through its input–output interaction with sustain stimulation that, unlike single stimuli used to study the reflex pathway, can strongly influence the interneuron circuitry and reveal a broader spectrum of connectivity.
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Affiliation(s)
- Jose Luis Vargas Luna
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20/4L, 1090, Vienna, Austria.
| | - Justin Brown
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114, USA
| | - Matthias J Krenn
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.,Center for Neuroscience and Neurological Recovery, Methodist Rehabilitation Center, 1350 East Woodrow Wilson, Jackson, MS, 39216, USA
| | - Barry McKay
- Hulse S.C.I. Research Lab, Shepherd Center, 2020 Peachtree Rd NW, Atlanta, GA, 30309, USA
| | - Winfried Mayr
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20/4L, 1090, Vienna, Austria
| | - John C Rothwell
- Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK
| | - Milan R Dimitrijevic
- Department of Rehabilitation and Physical Medicine, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA.,Foundation for Movement Recovery, Bolette Brygge 1, 0252, Oslo, Norway
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29
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Ibáñez J, Del Vecchio A, Rothwell JC, Baker SN, Farina D. Only the Fastest Corticospinal Fibers Contribute to β Corticomuscular Coherence. J Neurosci 2021; 41:4867-4879. [PMID: 33893222 PMCID: PMC8260170 DOI: 10.1523/jneurosci.2908-20.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/04/2021] [Accepted: 03/15/2021] [Indexed: 01/09/2023] Open
Abstract
Human corticospinal transmission is commonly studied using brain stimulation. However, this approach is biased to activity in the fastest conducting axons. It is unclear whether conclusions obtained in this context are representative of volitional activity in mild-to-moderate contractions. An alternative to overcome this limitation may be to study the corticospinal transmission of endogenously generated brain activity. Here, we investigate in humans (N = 19; of either sex), the transmission speeds of cortical β rhythms (∼20 Hz) traveling to arm (first dorsal interosseous) and leg (tibialis anterior; TA) muscles during tonic mild contractions. For this purpose, we propose two improvements for the estimation of corticomuscular β transmission delays. First, we show that the cumulant density (cross-covariance) is more accurate than the commonly-used directed coherence to estimate transmission delays in bidirectional systems transmitting band-limited signals. Second, we show that when spiking motor unit activity is used instead of interference electromyography, corticomuscular transmission delay estimates are unaffected by the shapes of the motor unit action potentials (MUAPs). Applying these improvements, we show that descending corticomuscular β transmission is only 1-2 ms slower than expected from the fastest corticospinal pathways. In the last part of our work, we show results from simulations using estimated distributions of the conduction velocities for descending axons projecting to lower motoneurons (from macaque histologic measurements) to suggest two scenarios that can explain fast corticomuscular transmission: either only the fastest corticospinal axons selectively transmit β activity, or else the entire pool does. The implications of these two scenarios for our understanding of corticomuscular interactions are discussed.SIGNIFICANCE STATEMENT We present and validate an improved methodology to measure the delay in the transmission of cortical β activity to tonically-active muscles. The estimated corticomuscular β transmission delays obtained with this approach are remarkably similar to those expected from transmission in the fastest corticospinal axons. A simulation of β transmission along a pool of corticospinal axons using an estimated distribution of fiber diameters suggests two possible mechanisms by which fast corticomuscular transmission is achieved: either a very small fraction of the fastest descending axons transmits β activity to the muscles or, alternatively, the entire population does and natural cancellation of slow channels occurs because of the distribution of axon diameters in the corticospinal tract.
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Affiliation(s)
- J Ibáñez
- Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
- Department of Clinical and Movement Disorders, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
| | - A Del Vecchio
- Department Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander University, Erlangen-Nürnberg, Erlangen 91052, Germany
| | - J C Rothwell
- Department of Clinical and Movement Disorders, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
| | - S N Baker
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - D Farina
- Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
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30
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Hordacre B, Austin D, Brown KE, Graetz L, Parees I, De Trane S, Vallence AM, Koblar S, Kleinig T, McDonnell MN, Greenwood R, Ridding MC, Rothwell JC. Evidence for a Window of Enhanced Plasticity in the Human Motor Cortex Following Ischemic Stroke. Neurorehabil Neural Repair 2021; 35:307-320. [PMID: 33576318 PMCID: PMC7610679 DOI: 10.1177/1545968321992330] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND In preclinical models, behavioral training early after stroke produces larger gains compared with delayed training. The effects are thought to be mediated by increased and widespread reorganization of synaptic connections in the brain. It is viewed as a period of spontaneous biological recovery during which synaptic plasticity is increased. OBJECTIVE To look for evidence of a similar change in synaptic plasticity in the human brain in the weeks and months after ischemic stroke. METHODS We used continuous theta burst stimulation (cTBS) to activate synapses repeatedly in the motor cortex. This initiates early stages of synaptic plasticity that temporarily reduces cortical excitability and motor-evoked potential amplitude. Thus, the greater the effect of cTBS on the motor-evoked potential, the greater the inferred level of synaptic plasticity. Data were collected from separate cohorts (Australia and UK). In each cohort, serial measurements were made in the weeks to months following stroke. Data were obtained for the ipsilesional motor cortex in 31 stroke survivors (Australia, 66.6 ± 17.8 years) over 12 months and the contralesional motor cortex in 29 stroke survivors (UK, 68.2 ± 9.8 years) over 6 months. RESULTS Depression of cortical excitability by cTBS was most prominent shortly after stroke in the contralesional hemisphere and diminished over subsequent sessions (P = .030). cTBS response did not differ across the 12-month follow-up period in the ipsilesional hemisphere (P = .903). CONCLUSIONS Our results provide the first neurophysiological evidence consistent with a period of enhanced synaptic plasticity in the human brain after stroke. Behavioral training given during this period may be especially effective in supporting poststroke recovery.
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Affiliation(s)
- Brenton Hordacre
- University of South Australia, IIMPACT in Health, Adelaide,
Australia
| | - Duncan Austin
- UCL Institute of Neurology, Queen Square, London, UK
| | | | - Lynton Graetz
- Lifespan Human Neurophysiology group, Adelaide Medical
School, The University of Adelaide, Australia
| | - Isabel Parees
- Servicio de Neurologia, Hospital Universitario Ramón
y Cajal, Madrid, Spain
- Servicio de Neurología, Hospital Ruber
Internacional, Madrid, Spain
| | - Stefania De Trane
- The Blizard Institute, Barts and The London School of
Medicine & Dentistry, Queen Mary University of London, London, UK
- Clinical Board: Medicine (Neuroscience), The Royal London
Hospital, Barts Health NHS Trust, London, UK
- National Hospital for Neurology and Neurosurgery, Queen
Square, London, UK
| | - Ann-Maree Vallence
- Discipline of Psychology, College of Science, Health,
Engineering and Education, Murdoch University, Western Australia, Australia
| | - Simon Koblar
- Department of Medicine, The University of Adelaide,
Adelaide, Australia
- Department of Neurology, Royal Adelaide Hospital,
Adelaide, Australia
| | - Timothy Kleinig
- Department of Medicine, The University of Adelaide,
Adelaide, Australia
- Department of Neurology, Royal Adelaide Hospital,
Adelaide, Australia
| | | | - Richard Greenwood
- National Hospital for Neurology and Neurosurgery, Queen
Square, London, UK
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31
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Latorre A, Rocchi L, Batla A, Berardelli A, Rothwell JC, Bhatia KP. The Signature of Primary Writing Tremor Is Dystonic. Mov Disord 2021; 36:1715-1720. [PMID: 33786886 DOI: 10.1002/mds.28579] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND It has been debated for decades whether primary writing tremor is a form of dystonic tremor, a variant of essential tremor, or a separate entity. We wished to test the hypothesis that primary writing tremor and dystonia share a common pathophysiology. OBJECTIVES The objective of the present study was to investigate the pathophysiological hallmarks of dystonia in patients affected by primary writing tremor. METHODS Ten patients with idiopathic dystonic tremor syndrome, 7 with primary writing tremor, 10 with essential tremor, and 10 healthy subjects were recruited. They underwent eyeblink classic conditioning, blink recovery cycle, and transcranial magnetic stimulation assessment, including motor-evoked potentials and short- and long-interval intracortical inhibition at baseline. Transcranial magnetic stimulation measures were also recorded after paired-associative plasticity protocol. RESULTS Primary writing tremor and dystonic tremor syndrome had a similar pattern of electrophysiological abnormalities, consisting of reduced eyeblink classic conditioning learning, reduced blink recovery cycle inhibition, and a lack of effect of paired-associative plasticity on long-interval intracortical inhibition. The latter 2 differ from those obtained in essential tremor and healthy subjects. Although not significant, slightly reduced short-interval intracortical inhibition and a larger effect of paired-associative plasticity in primary writing tremor and dystonic tremor syndrome, compared with essential tremor and healthy subjects, was observed. CONCLUSIONS Our initial hypothesis of a common pathophysiology between dystonia and primary writing tremor has been confirmed. Primary writing tremor might be considered a form of dystonic tremor. © 2021 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK.,Department of Human Neurosciences, University of Rome "Sapienza,", Rome, Italy
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK.,Department of Medical Sciences and Public Health, University of Cagliari, 09124, Cagliari, Italy
| | - Amit Batla
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK
| | - Alfredo Berardelli
- Department of Human Neurosciences, University of Rome "Sapienza,", Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK
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32
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Bootsma JM, Caljouw SR, Veldman MP, Maurits NM, Rothwell JC, Hortobágyi T. Neural Correlates of Motor Skill Learning Are Dependent on Both Age and Task Difficulty. Front Aging Neurosci 2021; 13:643132. [PMID: 33828478 PMCID: PMC8019720 DOI: 10.3389/fnagi.2021.643132] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/23/2021] [Indexed: 12/21/2022] Open
Abstract
Although a general age-related decline in neural plasticity is evident, the effects of age on neural plasticity after motor practice are inconclusive. Inconsistencies in the literature may be related to between-study differences in task difficulty. Therefore, we aimed to determine the effects of age and task difficulty on motor learning and associated brain activity. We used task-related electroencephalography (EEG) power in the alpha (8–12 Hz) and beta (13–30 Hz) frequency bands to assess neural plasticity before, immediately after, and 24-h after practice of a mirror star tracing task at one of three difficulty levels in healthy younger (19–24 yr) and older (65–86 yr) adults. Results showed an age-related deterioration in motor performance that was more pronounced with increasing task difficulty and was accompanied by a more bilateral activity pattern for older vs. younger adults. Task difficulty affected motor skill retention and neural plasticity specifically in older adults. Older adults that practiced at the low or medium, but not the high, difficulty levels were able to maintain improvements in accuracy at retention and showed modulation of alpha TR-Power after practice. Together, these data indicate that both age and task difficulty affect motor learning, as well as the associated neural plasticity.
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Affiliation(s)
- Josje M Bootsma
- Department of Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Simone R Caljouw
- Department of Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Menno P Veldman
- Movement Control and Neuroplasticity Research Group, Department of Movement Science, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Natasha M Maurits
- Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, United Kingdom
| | - Tibor Hortobágyi
- Department of Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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33
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Goldsworthy MR, Hordacre B, Rothwell JC, Ridding MC. Effects of rTMS on the brain: is there value in variability? Cortex 2021; 139:43-59. [PMID: 33827037 DOI: 10.1016/j.cortex.2021.02.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 02/16/2021] [Accepted: 02/26/2021] [Indexed: 01/02/2023]
Abstract
The ability of repetitive transcranial magnetic stimulation (rTMS) to non-invasively induce neuroplasticity in the human cortex has opened exciting possibilities for its application in both basic and clinical research. Changes in the amplitude of motor evoked potentials (MEPs) elicited by single-pulse transcranial magnetic stimulation has so far provided a convenient model for exploring the neurophysiology of rTMS effects on the brain, influencing the ways in which these stimulation protocols have been applied therapeutically. However, a growing number of studies have reported large inter-individual variability in the mean MEP response to rTMS, raising legitimate questions about the usefulness of this model for guiding therapy. Although the increasing application of different neuroimaging approaches has made it possible to probe rTMS-induced neuroplasticity outside the motor cortex to measure changes in neural activity that impact other aspects of human behaviour, the high variability of rTMS effects on these measurements remains an important issue for the field to address. In this review, we seek to move away from the conventional facilitation/inhibition dichotomy that permeates much of the rTMS literature, presenting a non-standard approach for measuring rTMS-induced neuroplasticity. We consider the evidence that rTMS is able to modulate an individual's moment-to-moment variability of neural activity, and whether this could have implications for guiding the therapeutic application of rTMS.
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Affiliation(s)
- Mitchell R Goldsworthy
- Lifespan Human Neurophysiology Group, Adelaide Medical School, University of Adelaide, Adelaide, Australia; Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia; Discipline of Psychiatry, Adelaide Medical School, University of Adelaide, Adelaide, Australia.
| | - Brenton Hordacre
- Innovation, IMPlementation and Clinical Translation (IIMPACT) in Health, University of South Australia, Adelaide, Australia
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Michael C Ridding
- Innovation, IMPlementation and Clinical Translation (IIMPACT) in Health, University of South Australia, Adelaide, Australia
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34
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Rawji V, Kaczmarczyk I, Rocchi L, Fong PY, Rothwell JC, Sharma N. Preconditioning Stimulus Intensity Alters Paired-Pulse TMS Evoked Potentials. Brain Sci 2021; 11:326. [PMID: 33806701 PMCID: PMC7998341 DOI: 10.3390/brainsci11030326] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 12/14/2022] Open
Abstract
Motor cortex (M1) paired-pulse TMS (ppTMS) probes excitatory and inhibitory intracortical dynamics by measurement of motor-evoked potentials (MEPs). However, MEPs reflect cortical and spinal excitabilities and therefore cannot isolate cortical function. Concurrent TMS-EEG has the ability to measure cortical function, while limiting peripheral confounds; TMS stimulates M1, whilst EEG acts as the readout: the TMS-evoked potential (TEP). Whilst varying preconditioning stimulus intensity influences intracortical inhibition measured by MEPs, the effects on TEPs is undefined. TMS was delivered to the left M1 using single-pulse and three, ppTMS paradigms, each using a different preconditioning stimulus: 70%, 80% or 90% of resting motor threshold. Corticospinal inhibition was present in all three ppTMS conditions. ppTMS TEP peaks were reduced predominantly under the ppTMS 70 protocol but less so for ppTMS 80 and not at all for ppTMS 90. There was a significant negative correlation between MEPs and N45 TEP peak for ppTMS 70 reaching statistical trends for ppTMS 80 and 90. Whilst ppTMS MEPs show inhibition across a range of preconditioning stimulus intensities, ppTMS TEPs do not. TEPs after M1 ppTMS vary as a function of preconditioning stimulus intensity: smaller preconditioning stimulus intensities result in better discriminability between conditioned and unconditioned TEPs. We recommend that preconditioning stimulus intensity should be minimized when using ppTMS to probe intracortical inhibition.
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Affiliation(s)
- Vishal Rawji
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK; (V.R.); (I.K.); (L.R.); (P.-Y.F.); (J.C.R.)
| | - Isabella Kaczmarczyk
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK; (V.R.); (I.K.); (L.R.); (P.-Y.F.); (J.C.R.)
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK; (V.R.); (I.K.); (L.R.); (P.-Y.F.); (J.C.R.)
- Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy
| | - Po-Yu Fong
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK; (V.R.); (I.K.); (L.R.); (P.-Y.F.); (J.C.R.)
- Neuroscience Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan City 333, Taiwan
- Division of Movement Disorders, Department of Neurology, Chang Gung Memorial Hospital at Linkou, Taoyuan City 333, Taiwan
| | - John C. Rothwell
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK; (V.R.); (I.K.); (L.R.); (P.-Y.F.); (J.C.R.)
| | - Nikhil Sharma
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK; (V.R.); (I.K.); (L.R.); (P.-Y.F.); (J.C.R.)
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35
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Kaczmarczyk I, Rawji V, Rothwell JC, Hodson-Tole E, Sharma N. Comparison between surface electrodes and ultrasound monitoring to measure TMS evoked muscle contraction. Muscle Nerve 2021; 63:724-729. [PMID: 33533504 DOI: 10.1002/mus.27192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/29/2021] [Accepted: 01/31/2021] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Transcranial magnetic stimulation (TMS) is widely used to explore cortical physiology in health and disease. Surface electromyography (sEMG) is appropriate for superficial muscles, but cannot be applied easily to less accessible muscles. Muscle ultrasound (mUS) may provide an elegant solution to this problem, but fundamental questions remain. We explore the relationship between TMS evoked muscle potentials and TMS evoked muscle contractions measured with mUS. METHODS In 10 participants, we performed a TMS recruitment curve, simultaneously measuring motor evoked potentials (MEPs) and mUS in biceps (BI), first dorsal interosseous (FDI), tibialis anterior (TA), and the tongue (TO). RESULTS Resting motor threshold (RMT) measurements and recruitment curves were found to be consistent across sEMG and mUS. DISCUSSION This work supports the use of TMS-US to study less accessible muscles. The implications are broad but could include the study of a new range of muscles in disorders such as amyotrophic lateral sclerosis.
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Affiliation(s)
- Isabella Kaczmarczyk
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Vishal Rawji
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - John C Rothwell
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Emma Hodson-Tole
- Musculoskeletal Sciences and Sports Medicine Research Centre, Manchester Metropolitan University, Manchester, UK
| | - Nikhil Sharma
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
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Latorre A, Rocchi L, Magrinelli F, Mulroy E, Berardelli A, Rothwell JC, Bhatia KP. Unravelling the enigma of cortical tremor and other forms of cortical myoclonus. Brain 2021; 143:2653-2663. [PMID: 32417917 DOI: 10.1093/brain/awaa129] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 02/11/2020] [Accepted: 02/27/2020] [Indexed: 12/21/2022] Open
Abstract
Cortical tremor is a fine rhythmic oscillation involving distal upper limbs, linked to increased sensorimotor cortex excitability, as seen in cortical myoclonus. Cortical tremor is the hallmark feature of autosomal dominant familial cortical myoclonic tremor and epilepsy (FCMTE), a syndrome not yet officially recognized and characterized by clinical and genetic heterogeneity. Non-coding repeat expansions in different genes have been recently recognized to play an essential role in its pathogenesis. Cortical tremor is considered a rhythmic variant of cortical myoclonus and is part of the 'spectrum of cortical myoclonus', i.e. a wide range of clinical motor phenomena, from reflex myoclonus to myoclonic epilepsy, caused by abnormal sensorimotor cortical discharges. The aim of this update is to provide a detailed analysis of the mechanisms defining cortical tremor, as seen in FCMTE. After reviewing the clinical and genetic features of FCMTE, we discuss the possible mechanisms generating the distinct elements of the cortical myoclonus spectrum, and how cortical tremor fits into it. We propose that the spectrum is due to the evolution from a spatially limited focus of excitability to recruitment of more complex mechanisms capable of sustaining repetitive activity, overcoming inhibitory mechanisms that restrict excitatory bursts, and engaging wide areas of cortex. Finally, we provide evidence for a possible common denominator of the elements of the spectrum, i.e. the cerebellum, and discuss its role in FCMTE, according to recent genetic findings.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
- Department of Human Neurosciences, Sapienza University of Rome, Italy
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Francesca Magrinelli
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Eoin Mulroy
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza University of Rome, Italy
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, IS, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
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Vallence AM, Dansie K, Goldsworthy MR, McAllister SM, Yang R, Rothwell JC, Ridding MC. Examining motor evoked potential amplitude and short-interval intracortical inhibition on the up-going and down-going phases of a transcranial alternating current stimulation (tacs) imposed alpha oscillation. Eur J Neurosci 2021; 53:2755-2762. [PMID: 33480046 DOI: 10.1111/ejn.15124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 12/19/2020] [Accepted: 01/17/2021] [Indexed: 01/18/2023]
Abstract
Many brain regions exhibit rhythmical activity thought to reflect the summed behaviour of large populations of neurons. The endogenous alpha rhythm has been associated with phase-dependent modulation of corticospinal excitability. However, whether exogenous alpha rhythm, induced using transcranial alternating current stimulation (tACS) also has a phase-dependent effect on corticospinal excitability remains unknown. Here, we triggered transcranial magnetic stimuli (TMS) on the up- or down-going phase of a tACS-imposed alpha oscillation and measured motor evoked potential (MEP) amplitude and short-interval intracortical inhibition (SICI). There was no significant difference in MEP amplitude or SICI when TMS was triggered on the up- or down-going phase of the tACS-imposed alpha oscillation. The current study provides no evidence of differences in corticospinal excitability or GABAergic inhibition when targeting the up-going (peak) and down-going (trough) phase of the tACS-imposed oscillation.
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Affiliation(s)
- Ann-Maree Vallence
- Discipline of Psychology, College of Science, Health, Engineering, and Education, Murdoch University, Perth, Australia
| | - Kathryn Dansie
- Australia and New Zealand Dialysis and Transplant Registry (ANZDATA), South Australian Health and Medical Research Institute (SAHMIR), Adelaide, South, Australia
| | - Mitchell R Goldsworthy
- Adelaide Medical School, University of Adelaide, Adelaide, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Suzanne M McAllister
- Formerly of the Discipline of Physiology, School of Medical Science, University of Adelaide, Adelaide, Australia
| | | | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - Michael C Ridding
- University of South Australia, IIMPACT in Health, Adelaide, Australia
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Obeso I, Herrero MT, Ligneul R, Rothwell JC, Jahanshahi M. A Causal Role for the Right Dorsolateral Prefrontal Cortex in Avoidance of Risky Choices and Making Advantageous Selections. Neuroscience 2021; 458:166-179. [PMID: 33476698 DOI: 10.1016/j.neuroscience.2020.12.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/30/2020] [Accepted: 12/31/2020] [Indexed: 11/29/2022]
Abstract
In everyday life, risky decision-making relies on multiple cognitive processes including sensitivity to reinforcers, exploration, learning, and forgetting. Neuroimaging evidence suggests that the dorsolateral prefrontal cortex (DLPFC) is involved in exploration and risky decision-making, but the nature of its computations and its causal role remain uncertain. We provide evidence for the role of the DLPFC in value-independent, directed exploration on the Iowa Gambling Task (IGT) and we describe a new computational model to account for the competition of directed exploration and exploitation in guiding decisions. Forty-two healthy human participants were included in a right DLPFC, left DLPFC or sham stimulation groups using continuous theta-burst stimulation (cTBS). Immediately after cTBS, the IGT was completed. Computational modelling was used to account for exploration and exploitation with different combinations with value-based and sensitivity to reinforcers for each group. Applying cTBS to the left and right DLPFC selectively decreased directed exploration on the IGT compared to sham stimulation. Model-based analyses further indicated that the right (but not the left) DLPFC stimulation increased sensitivity to reinforcers, leading to avoidance of risky choices and promoting advantageous choices during the task. Although these findings are based on small sample sizes per group, they nevertheless elucidate the causal role of the right DLPFC in governing the exploration-exploitation tradeoff during decision-making in uncertain and ambiguous contexts.
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Affiliation(s)
- Ignacio Obeso
- HM Hospitales - HM CINAC, 28938 Móstoles, and CEU-San Pablo University, 28003 Madrid, Spain.
| | - Maria-Trinidad Herrero
- Clinical & Experimental Neuroscience (NiCE-IMIB-IUIE), Department of Human Anatomy & Psychobiology, School of Medicine, Campus Espinardo, University of Murcia, 30071 Murcia, Spain
| | - Romain Ligneul
- Donders Institute for Brain, Cognition and Behaviour, Montessorilaan 3, 6525 HR Nijmejen, Netherlands
| | - John C Rothwell
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, 33 Queen Square, London WC1N3BG, United Kingdom
| | - Marjan Jahanshahi
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, 33 Queen Square, London WC1N3BG, United Kingdom; Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu, China.
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Ginatempo F, Loi N, Rothwell JC, Deriu F. Physiological Differences in Hand and Face Areas of the Primary Motor Cortex in Skilled Wind and String Musicians. Neuroscience 2020; 455:141-150. [PMID: 33359658 DOI: 10.1016/j.neuroscience.2020.12.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 10/22/2022]
Abstract
The process of learning and playing a musical instrument modulates the structural and functional organization of cortical motor networks. In the present study the excitability and short-term functional plasticity of face and hand areas of primary motor cortex (M1) were compared in woodwind musicians (WM), string musicians (SM) and non-musicians (NM) to test the hypothesis that neurophysiological adaptations to the long-term experience of playing a musical instrument are site-specific and related to the particular physiological properties of the representation area in M1. Twenty-two musicians (11 SM, 11 WM) and 11 NM participated in the study. Transcranial magnetic stimulation (TMS) was used to probe rest and active short-latency intracortical inhibition (SICI), interhemispheric inhibition (IHI) and response to paired associative stimulation (PAS). TMS-induced motor evoked potentials (MEP) were recorded from the depressor anguli oris (DAO) and the first dorsal interosseous (FDI) muscles, respectively. Rest and active SICI were the same in all groups (all p > 0.05). WM exhibited significant IHI in the DAO (p = 0.031), in contrast to its absence in SM and NM. Compared with NM and WM, the PAS-induced increase in MEP amplitude in SM was significantly larger in hand M1 (p = 0.008) but not in face M1. In conclusion, neurophysiological adaptations differ between WM, in whom control of the embouchure is highly important, and SM who perform a large range of sequential finger movements and are site-specific in M1.
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Affiliation(s)
| | - Nicola Loi
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
| | - Franca Deriu
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
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40
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Berlot R, Rothwell JC, Bhatia KP, Kojović M. Variability of Movement Disorders: The Influence of Sensation, Action, Cognition, and Emotions. Mov Disord 2020; 36:581-593. [PMID: 33332680 DOI: 10.1002/mds.28415] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/02/2020] [Accepted: 11/16/2020] [Indexed: 12/13/2022] Open
Abstract
Patients with movement disorders experience fluctuations unrelated to disease progression or treatment. Extrinsic factors that contribute to the variable expression of movement disorders are environment related. They influence the expression of movement disorders through sensory-motor interactions and include somatosensory, visual, and auditory stimuli. Examples of somatosensory effects are stimulus sensitivity of myoclonus on touch and sensory amelioration in dystonia but also some less-appreciated effects on parkinsonian tremor and gait. Changes in visual input may affect practically all types of movement disorders, either by loss of its compensatory role or by disease-related alterations in the pathways subserving visuomotor integration. The interaction between auditory input and motor function is reflected in simple protective reflexes and in complex behaviors such as singing or dancing. Various expressions range from the effect of music on parkinsonian bradykinesia to tics. Changes in body position affect muscle tone and may result in marked fluctuations of rigidity or may affect dystonic manifestations. Factors intrinsic to the patient are related to their voluntary activity and cognitive, motivational, and emotional states. Depending on the situation or disease, they may improve or worsen movement disorders. We discuss various factors that can influence the phenotypic variability of movement disorders, highlighting the potential mechanisms underlying these manifestations. We also describe how motor fluctuations can be provoked during the clinical assessment to help reach the diagnosis and appreciated to understand complaints that seem discrepant with objective findings. We summarize advice and interventions based on the variability of movement disorders that may improve patients' functioning in everyday life. © 2020 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Rok Berlot
- Department of Neurology, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - John C Rothwell
- Department of Clinical and Motor Neuroscience, UCL Institute of Neurology, Queen Square, London, United Kingdom
| | - Kailash P Bhatia
- Department of Clinical and Motor Neuroscience, UCL Institute of Neurology, Queen Square, London, United Kingdom
| | - Maja Kojović
- Department of Neurology, University Medical Centre Ljubljana, Ljubljana, Slovenia
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41
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Latorre A, Cocco A, Bhatia KP, Erro R, Antelmi E, Conte A, Rothwell JC, Rocchi L. Defective Somatosensory Inhibition and Plasticity Are Not Required to Develop Dystonia. Mov Disord 2020; 36:1015-1021. [PMID: 33332649 DOI: 10.1002/mds.28427] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/21/2020] [Accepted: 11/18/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Dystonia may have different neuroanatomical substrates and pathophysiology. This is supported by studies on the motor system showing, for instance, that plasticity is abnormal in idiopathic dystonia, but not in dystonia secondary to basal ganglia lesions. OBJECTIVE The aim of this study was to test whether somatosensory inhibition and plasticity abnormalities reported in patients with idiopathic dystonia also occur in patients with dystonia caused by basal ganglia damage. METHODS Ten patients with acquired dystonia as a result of basal ganglia lesions and 12 healthy control subjects were recruited. They underwent electrophysiological testing at baseline and after a single 45-minute session of high-frequency repetitive somatosensory stimulation. Electrophysiological testing consisted of somatosensory temporal discrimination, somatosensory-evoked potentials (including measurement of early and late high-frequency oscillations and the spatial inhibition ratio of N20/25 and P14 components), the recovery cycle of paired-pulse somatosensory-evoked potentials, and primary motor cortex short-interval intracortical inhibition. RESULTS Unlike previous reports of patients with idiopathic dystonia, patients with acquired dystonia did not differ from healthy control subjects in any of the electrophysiological measures either before or after high-frequency repetitive somatosensory stimulation, except for short-interval intracortical inhibition, which was reduced at baseline in patients compared to control subjects. CONCLUSIONS The data show that reduced somatosensory inhibition and enhanced cortical plasticity are not required for the clinical expression of dystonia, and that the abnormalities reported in idiopathic dystonia are not necessarily linked to basal ganglia damage. © 2020 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Antoniangela Cocco
- Department of Neurology, IRCCS Humanitas Research Hospital, Milan, Italy.,Department of Neuroscience, Catholic University, Milan, Italy
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Roberto Erro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Elena Antelmi
- Neurology Unit, Movement Disorders Division, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Antonella Conte
- Department of Human Neurosciences, Sapienza, University of Rome, Rome, Italy.,IRCCS Neuromed, Pozzilli, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
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Jha A, Menozzi E, Oyekan R, Latorre A, Mulroy E, Schreglmann SR, Stamate C, Daskalopoulos I, Kueppers S, Luchini M, Rothwell JC, Roussos G, Bhatia KP. The CloudUPDRS smartphone software in Parkinson's study: cross-validation against blinded human raters. NPJ Parkinsons Dis 2020; 6:36. [PMID: 33293531 PMCID: PMC7722731 DOI: 10.1038/s41531-020-00135-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 10/23/2020] [Indexed: 12/17/2022]
Abstract
Digital assessments of motor severity could improve the sensitivity of clinical trials and personalise treatment in Parkinson’s disease (PD) but have yet to be widely adopted. Their ability to capture individual change across the heterogeneous motor presentations typical of PD remains inadequately tested against current clinical reference standards. We conducted a prospective, dual-site, crossover-randomised study to determine the ability of a 16-item smartphone-based assessment (the index test) to predict subitems from the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale part III (MDS-UPDRS III) as assessed by three blinded clinical raters (the reference-standard). We analysed data from 60 subjects (990 smartphone tests, 2628 blinded video MDS-UPDRS III subitem ratings). Subject-level predictive performance was quantified as the leave-one-subject-out cross-validation (LOSO-CV) accuracy. A pre-specified analysis classified 70.3% (SEM 5.9%) of subjects into a similar category to any of three blinded clinical raters and was better than random (36.7%; SEM 4.3%) classification. Post hoc optimisation of classifier and feature selection improved performance further (78.7%, SEM 5.1%), although individual subtests were variable (range 53.2–97.0%). Smartphone-based measures of motor severity have predictive value at the subject level. Future studies should similarly mitigate against subjective and feature selection biases and assess performance across a range of motor features as part of a broader strategy to avoid overly optimistic performance estimates.
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Affiliation(s)
- Ashwani Jha
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.
| | - Elisa Menozzi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Rebecca Oyekan
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Queen Square Movement Disorders Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Eoin Mulroy
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Sebastian R Schreglmann
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | | | | | | | | | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - George Roussos
- Queen Square Movement Disorders Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.
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Erro R, Antelmi E, Bhatia KP, Latorre A, Tinazzi M, Berardelli A, Rothwell JC, Rocchi L. Reversal of Temporal Discrimination in Cervical Dystonia after Low-Frequency Sensory Stimulation. Mov Disord 2020; 36:761-766. [PMID: 33159823 DOI: 10.1002/mds.28369] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 09/26/2020] [Accepted: 10/12/2020] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Somatosensory temporal discrimination is abnormal in dystonia and reflects reduced somatosensory inhibition. In healthy individuals, both the latter are enhanced by high-frequency repetitive somatosensory stimulation, whereas opposite effects are observed in patients with cervical dystonia. OBJECTIVES We tested whether low-frequency repetitive sensory stimulation, which in healthy individuals worsens discrimination, might have the opposite effect in patients with cervical dystonia at the physiological level and, in turn, improve their perceptual performance. METHODS Somatosensory temporal discrimination and several electrophysiological measures of sensorimotor inhibition were collected before and after 45 minutes of low-frequency repetitive sensory stimulation. RESULTS As predicted, and opposite to what happened in controls, low-frequency repetitive sensory stimulation in patients enhanced sensorimotor inhibition and normalized somatosensory temporal discrimination. CONCLUSIONS Patients with cervical dystonia have an abnormal response to repetitive sensory stimulation, which we hypothesize is attributed to abnormally sensitive homeostatic mechanisms of inhibitory circuitry in both sensory and motor systems. © 2020 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Roberto Erro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi (SA), Italy
| | - Elena Antelmi
- Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Verona, Italy
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, University College London, Queen Square Institute of Neurology, London, UK
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, University College London, Queen Square Institute of Neurology, London, UK
- Department of Human Neurosciences, University of Rome "Sapienza", Rome, Italy
| | - Michele Tinazzi
- Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Verona, Italy
| | - Alfredo Berardelli
- Department of Human Neurosciences, University of Rome "Sapienza", Rome, Italy
- IRCCS Neuromed Institute, Pozzilli, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, University College London, Queen Square Institute of Neurology, London, UK
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, University College London, Queen Square Institute of Neurology, London, UK
- Department of Human Neurosciences, University of Rome "Sapienza", Rome, Italy
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Rawji V, Latorre A, Sharma N, Rothwell JC, Rocchi L. On the Use of TMS to Investigate the Pathophysiology of Neurodegenerative Diseases. Front Neurol 2020; 11:584664. [PMID: 33224098 PMCID: PMC7669623 DOI: 10.3389/fneur.2020.584664] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 10/05/2020] [Indexed: 12/22/2022] Open
Abstract
Neurodegenerative diseases are a collection of disorders that result in the progressive degeneration and death of neurons. They are clinically heterogenous and can present as deficits in movement, cognition, executive function, memory, visuospatial awareness and language. Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation tool that allows for the assessment of cortical function in vivo. We review how TMS has been used for the investigation of three neurodegenerative diseases that differ in their neuroanatomical axes: (1) Motor cortex-corticospinal tract (motor neuron diseases), (2) Non-motor cortical areas (dementias), and (3) Subcortical structures (parkinsonisms). We also make four recommendations that we hope will benefit the use of TMS in neurodegenerative diseases. Firstly, TMS has traditionally been limited by the lack of an objective output and so has been confined to stimulation of the motor cortex; this limitation can be overcome by the use of concurrent neuroimaging methods such as EEG. Given that neurodegenerative diseases progress over time, TMS measures should aim to track longitudinal changes, especially when the aim of the study is to look at disease progression and symptomatology. The lack of gold-standard diagnostic confirmation undermines the validity of findings in clinical populations. Consequently, diagnostic certainty should be maximized through a variety of methods including multiple, independent clinical assessments, imaging and fluids biomarkers, and post-mortem pathological confirmation where possible. There is great interest in understanding the mechanisms by which symptoms arise in neurodegenerative disorders. However, TMS assessments in patients are usually carried out during resting conditions, when the brain network engaged during these symptoms is not expressed. Rather, a context-appropriate form of TMS would be more suitable in probing the physiology driving clinical symptoms. In all, we hope that the recommendations made here will help to further understand the pathophysiology of neurodegenerative diseases.
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Affiliation(s)
| | | | | | | | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
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45
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Latorre A, Rothwell JC. Myoclonus and COVID-19: A Challenge for the Present, a Lesson for the Future. Mov Disord Clin Pract 2020; 7:888-890. [PMID: 33163558 PMCID: PMC7604694 DOI: 10.1002/mdc3.13103] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 12/11/2022] Open
Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement NeurosciencesUniversity College London (UCL) Queen Square Institute of NeurologyLondonUnited Kingdom
| | - John C. Rothwell
- Department of Clinical and Movement NeurosciencesUniversity College London (UCL) Queen Square Institute of NeurologyLondonUnited Kingdom
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Bootsma JM, Caljouw SR, Veldman MP, Maurits NM, Rothwell JC, Hortobágyi T. Failure to Engage Neural Plasticity through Practice of a High-difficulty Task is Accompanied by Reduced Motor Skill Retention in Older Adults. Neuroscience 2020; 451:22-35. [PMID: 33075459 DOI: 10.1016/j.neuroscience.2020.10.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/29/2022]
Abstract
While the difficulty of a motor task can act as a stimulus for learning in younger adults, it is unknown how task difficulty interacts with age-related reductions in motor performance and altered brain activation. We examined the effects of task difficulty on motor performance and used electroencephalography (EEG) to probe task-related brain activation after acquisition and 24-h retention of a mirror star-tracing skill in healthy older adults (N = 36, 65-86 years). The results showed that the difficulty of the motor skill affected both the magnitude of motor skill learning and the underlying neural mechanisms. Behavioral data revealed that practicing a motor task at a high difficulty level hindered motor skill consolidation. The EEG data indicated that task difficulty modulated changes in brain activation after practice. Specifically, a decrease in task-related alpha power in frontal and parietal electrodes was only present after practice of the skill at the low and medium, but not the high difficulty level. Taken together, our findings show that a failure to engage neural plasticity through practice of a high-difficulty task is accompanied by reduced motor skill retention in older adults. The data help us better understand how older adults learn new motor skills and might have implications for prescribing motor skill practice according to its difficulty in rehabilitation settings.
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Affiliation(s)
- Josje M Bootsma
- Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Simone R Caljouw
- Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Menno P Veldman
- Movement Control and Neuroplasticity Research Group, Department of Movement Science, KU Leuven, Leuven, Belgium; Leuven Brain Institute, Leuven, Belgium
| | - Natasha M Maurits
- Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, United Kingdom
| | - Tibor Hortobágyi
- Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Latorre A, Rocchi L, Magrinelli F, Mulroy E, Berardelli A, Rothwell JC, Bhatia KP. Reply: Pentameric repeat expansions: cortical myoclonus or cortical tremor? and Cortical tremor: a tantalizing conundrum between cortex and cerebellum. Brain 2020; 143:e88. [PMID: 33011762 DOI: 10.1093/brain/awaa261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Francesca Magrinelli
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Eoin Mulroy
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza University of Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, IS, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK
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Silvennoinen K, Balestrini S, Rothwell JC, Sisodiya SM. Transcranial magnetic stimulation as a tool to understand genetic conditions associated with epilepsy. Epilepsia 2020; 61:1818-1839. [PMID: 32783192 PMCID: PMC8432162 DOI: 10.1111/epi.16634] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/09/2020] [Accepted: 07/09/2020] [Indexed: 12/30/2022]
Abstract
Advances in genetics may enable a deeper understanding of disease mechanisms and promote a shift to more personalised medicine in the epilepsies. At present, understanding of consequences of genetic variants mainly relies on preclinical functional work; tools for acquiring similar data from the living human brain are needed. Transcranial magnetic stimulation (TMS), in particular paired-pulse TMS protocols which depend on the function of cortical GABAergic interneuron networks, has the potential to become such a tool. For this report, we identified and reviewed 23 publications on TMS studies of cortical excitability and inhibition in 15 different genes or conditions relevant to epilepsy. Reduced short-interval intracortical inhibition (SICI) and reduced cortical silent period (CSP) duration were the most commonly reported findings, suggesting abnormal GABAA - (SICI) or GABAB ergic (CSP) signalling. For several conditions, these findings are plausible based on established evidence of involvement of the GABAergic system; for some others, they may inform future research around such mechanisms. Challenges of TMS include lack of complete understanding of the neural underpinnings of the measures used: hypotheses and analyses should be based on existing clinical and preclinical data. Further pitfalls include gathering sufficient numbers of participants, and the effect of confounding factors, especially medications. TMS-EEG is a unique perturbational technique to study the intrinsic properties of the cortex with excellent temporal resolution; while it has the potential to provide further information of use in interpreting effects of genetic variants, currently the links between measures and neurophysiology are less established. Despite these challenges, TMS is a tool with potential for elucidating the system-level in vivo functional consequences of genetic variants in people carrying genetic changes of interest, providing unique insights.
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Affiliation(s)
- Katri Silvennoinen
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St. Peter, UK
| | - Simona Balestrini
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St. Peter, UK
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, Department of UCL Queen Square, Institute of Neurology, London, UK
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St. Peter, UK
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Rawji V, Modi S, Latorre A, Rocchi L, Hockey L, Bhatia K, Joyce E, Rothwell JC, Jahanshahi M. Impaired automatic but intact volitional inhibition in primary tic disorders. Brain 2020; 143:906-919. [PMID: 32125364 PMCID: PMC7089661 DOI: 10.1093/brain/awaa024] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 11/02/2019] [Accepted: 12/11/2019] [Indexed: 01/10/2023] Open
Abstract
The defining character of tics is that they can be transiently suppressed by volitional effort of will, and at a behavioural level this has led to the concept that tics result from a failure of inhibition. However, this logic conflates the mechanism responsible for the production of tics with that used in suppressing them. Volitional inhibition of motor output could be increased to prevent the tic from reaching the threshold for expression, although this has been extensively investigated with conflicting results. Alternatively, automatic inhibition could prevent the initial excitation of the striatal tic focus-a hypothesis we have previously introduced. To reconcile these competing hypotheses, we examined different types of motor inhibition in a group of 19 patients with primary tic disorders and 15 healthy volunteers. We probed proactive and reactive inhibition using the conditional stop-signal task, and applied transcranial magnetic stimulation to the motor cortex, to assess movement preparation and execution. We assessed automatic motor inhibition with the masked priming task. We found that volitional movement preparation, execution and inhibition (proactive and reactive) were not impaired in tic disorders. We speculate that these mechanisms are recruited during volitional tic suppression, and that they prevent expression of the tic by inhibiting the nascent excitation released by the tic generator. In contrast, automatic inhibition was abnormal/impaired in patients with tic disorders. In the masked priming task, positive and negative compatibility effects were found for healthy controls, whereas patients with tics exhibited strong positive compatibility effects, but no negative compatibility effect indicative of impaired automatic inhibition. Patients also made more errors on the masked priming task than healthy control subjects and the types of errors were consistent with impaired automatic inhibition. Errors associated with impaired automatic inhibition were positively correlated with tic severity. We conclude that voluntary movement preparation/generation and volitional inhibition are normal in tic disorders, whereas automatic inhibition is impaired-a deficit that correlated with tic severity and thus may constitute a potential mechanism by which tics are generated.
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Affiliation(s)
- Vishal Rawji
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Sachin Modi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Leanne Hockey
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Kailash Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Eileen Joyce
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Marjan Jahanshahi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK
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Ugawa Y, Rothwell JC, Paulus W. Possible role of backpropagating action potentials in corticospinal neurons in I-wave periodicity following a TMS pulse. Neurosci Res 2020; 156:234-236. [DOI: 10.1016/j.neures.2019.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/17/2019] [Accepted: 09/27/2019] [Indexed: 10/25/2022]
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