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Rurak BK, Rodrigues JP, Power BD, Drummond PD, Vallence AM. Reduced SMA-M1 connectivity in older than younger adults measured using dual-site TMS. Eur J Neurosci 2021; 54:6533-6552. [PMID: 34470079 DOI: 10.1111/ejn.15438] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 08/18/2021] [Indexed: 12/29/2022]
Abstract
With advancing age comes a decline in voluntary movement control. Growing evidence suggests that an age-related decline in effective connectivity between the supplementary motor area and primary motor cortex (SMA-M1) might play a role in an age-related decline of bilateral motor control. Dual-site transcranial magnetic stimulation (TMS) can be used to measure SMA-M1 effective connectivity. In the current study, we aimed to (1) replicate previous dual-site TMS research showing reduced SMA-M1 connectivity in older than younger adults and (2) examine whether SMA-M1 connectivity is associated with bilateral motor control in independent samples of younger (n = 30) and older adults (n = 30). SMA-M1 connectivity was measured using dual-site TMS with interstimulus intervals of 6, 7 and 8 ms, and bilateral motor control was measured using the Purdue Pegboard, Four Square Step Test and the Timed Up and Go task. Findings from this study showed that SMA-M1 connectivity was reduced in older than in younger adults, suggesting that the direct excitatory connections between SMA and M1 had reduced efficacy in older than younger adults. Furthermore, greater SMA-M1 connectivity was associated with better bimanual motor control in older adults. Thus, SMA-M1 connectivity in older adults might underpin, in part, the age-related decline in bilateral motor control. These findings contribute to our understanding of age-related declines in motor control and provide a physiological basis for the development of interventions to improve bimanual and bilateral motor control.
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Affiliation(s)
- Brittany K Rurak
- Discipline of Psychology, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, Western Australia, Australia.,Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
| | | | - Brian D Power
- Hollywood Private Hospital, Nedlands, Western Australia, Australia.,School of Medicine Fremantle, University of Notre Dame, Fremantle, Western Australia, Australia
| | - Peter D Drummond
- Discipline of Psychology, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, Western Australia, Australia.,Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
| | - Ann-Maree Vallence
- Discipline of Psychology, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, Western Australia, Australia.,Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia.,Centre for Molecular Medicine and Innovative Therapeutics, Murdoch, Western Australia, Australia
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2
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Corp DT, Bereznicki HGK, Clark GM, Youssef GJ, Fried PJ, Jannati A, Davies CB, Gomes-Osman J, Kirkovski M, Albein-Urios N, Fitzgerald PB, Koch G, Di Lazzaro V, Pascual-Leone A, Enticott PG. Large-scale analysis of interindividual variability in single and paired-pulse TMS data. Clin Neurophysiol 2021; 132:2639-2653. [PMID: 34344609 DOI: 10.1016/j.clinph.2021.06.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 06/22/2021] [Accepted: 06/29/2021] [Indexed: 01/01/2023]
Abstract
OBJECTIVE This study brought together over 60 transcranial magnetic stimulation (TMS) researchers to create the largest known sample of individual participant single and paired-pulse TMS data to date, enabling a more comprehensive evaluation of factors driving response variability. METHODS Authors of previously published studies were contacted and asked to share deidentified individual TMS data. Mixed-effects regression investigated a range of individual and study level variables for their contribution to variability in response to single and paired-pulse TMS data. RESULTS 687 healthy participant's data were pooled across 35 studies. Target muscle, pulse waveform, neuronavigation use, and TMS machine significantly predicted an individual's single-pulse TMS amplitude. Baseline motor evoked potential amplitude, motor cortex hemisphere, and motor threshold (MT) significantly predicted short-interval intracortical inhibition response. Baseline motor evoked potential amplitude, test stimulus intensity, interstimulus interval, and MT significantly predicted intracortical facilitation response. Age, hemisphere, and TMS machine significantly predicted MT. CONCLUSIONS This large-scale analysis has identified a number of factors influencing participants' responses to single and paired-pulse TMS. We provide specific recommendations to minimise interindividual variability in single and paired-pulse TMS data. SIGNIFICANCE This study has used large-scale analyses to give clarity to factors driving variance in TMS data. We hope that this ongoing collaborative approach will increase standardisation of methods and thus the utility of single and paired-pulse TMS.
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Affiliation(s)
- Daniel T Corp
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Australia; Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| | - Hannah G K Bereznicki
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Australia
| | - Gillian M Clark
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Australia
| | - George J Youssef
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Australia; Centre for Adolescent Health, Murdoch Children's Research Institute, Parkville, Australia
| | - Peter J Fried
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Ali Jannati
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Neuromodulation Program and Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Charlotte B Davies
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Australia
| | - Joyce Gomes-Osman
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Department of Physical Therapy, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Melissa Kirkovski
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Australia
| | - Natalia Albein-Urios
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Australia
| | - Paul B Fitzgerald
- Monash Alfred Psychiatry Research Centre, Central Clinical School, The Alfred and Monash University, Melbourne, Australia; Epworth Centre for Innovation in Mental Health, Epworth HealthCare and Central Clinical School, Melbourne, Australia
| | - Giacomo Koch
- Non-invasive Brain Stimulation Unit, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy; Department of Biomedical and Specialty Surgical Sciences, Section of Human Physiology, University of Ferrara, Italy
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology and Neurobiology, Università Campus Bio-Medico, Rome, Italy
| | - Alvaro Pascual-Leone
- Hinda and Arthur Marcus Institute for Aging Research and Deanna and Sidney Wolk Center for Memory Health, Hebrew SeniorLife, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Guttmann Brain Health Institute, Institut Guttmann de Neurorehabilitació, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Peter G Enticott
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Australia
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3
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Lavrador JP, Gioti I, Hoppe S, Jung J, Patel S, Gullan R, Ashkan K, Bhangoo R, Vergani F. Altered Motor Excitability in Patients With Diffuse Gliomas Involving Motor Eloquent Areas: The Impact of Tumor Grading. Neurosurgery 2021; 88:183-192. [PMID: 32888309 DOI: 10.1093/neuros/nyaa354] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 06/19/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Diffuse gliomas have an increased biological aggressiveness across the World Health Organization (WHO) grading system. The implications of glioma grading on the primary motor cortex (M1)-corticospinal tract (CST) excitability is unknown. OBJECTIVE To assess the excitability of the motor pathway with navigated transcranial magnetic stimulation (nTMS). METHODS Retrospective cohort study of patients admitted for surgery with diffuse gliomas within motor eloquent areas. Demographic, clinical, and nTMS-related variables were collected. The Cortical Excitability Score (CES 0 to 2 according to the number of abnormal interhemispheric resting motor threshold (RMT) ratios) was calculated for patients where bilateral upper and lower limb mapping was performed. RESULTS A total of 45 patients were included: 9 patients had a low-grade glioma and 36 patients had a high-grade glioma. The unadjusted analysis revealed an increase in the latency of the motor evoked potential of the lower limb with an increase of the WHO grade (P = .038). The adjusted analysis confirmed this finding (P = .013) and showed a relation between the increase in the WHO and a decreased RMT (P = .037) of the motor evoked responses in the lower limb. When CES was calculated, an increase in the score was related with an increase in the WHO grade (unadjusted analysis-P = .0001; adjusted analysis-P = .001) and in isocitrate dehydrogenase (IDH) wild-type tumors (unadjusted analysis-P = .020). CONCLUSION An increase in the WHO grading system and IDH wild-type tumors are associated with an abnormal excitability of the motor eloquent areas in patients with diffuse gliomas.
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Affiliation(s)
- José Pedro Lavrador
- Neurosurgical Department, King's College Hospital Foundation Trust, London, United Kingdom
| | - Ifigeneia Gioti
- Neurosurgical Department, King's College Hospital Foundation Trust, London, United Kingdom
| | - Szymon Hoppe
- Neurosurgical Department, King's College Hospital Foundation Trust, London, United Kingdom
| | - Josephine Jung
- Neurosurgical Department, King's College Hospital Foundation Trust, London, United Kingdom
| | - Sabina Patel
- Neurosurgical Department, King's College Hospital Foundation Trust, London, United Kingdom
| | - Richard Gullan
- Neurosurgical Department, King's College Hospital Foundation Trust, London, United Kingdom
| | - Keyoumars Ashkan
- Neurosurgical Department, King's College Hospital Foundation Trust, London, United Kingdom
| | - Ranjeev Bhangoo
- Neurosurgical Department, King's College Hospital Foundation Trust, London, United Kingdom
| | - Francesco Vergani
- Neurosurgical Department, King's College Hospital Foundation Trust, London, United Kingdom
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4
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Hupfeld KE, Swanson CW, Fling BW, Seidler RD. TMS-induced silent periods: A review of methods and call for consistency. J Neurosci Methods 2020; 346:108950. [PMID: 32971133 PMCID: PMC8276277 DOI: 10.1016/j.jneumeth.2020.108950] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/24/2020] [Accepted: 09/15/2020] [Indexed: 12/31/2022]
Abstract
Transcranial magnetic stimulation (TMS)-induced silent periods provide an in vivo measure of human motor cortical inhibitory function. Cortical silent periods (cSP, also sometimes referred to as contralateral silent periods) and ipsilateral silent periods (iSP) may change with advancing age and disease and can provide insight into cortical control of the motor system. The majority of past silent period work has implemented largely varying methodology, sometimes including subjective analyses and incomplete methods descriptions. This limits reproducibility of silent period work and hampers comparisons of silent period measures across studies. Here, we discuss methodological differences in past silent period work, highlighting how these choices affect silent period outcome measures. We also outline challenges and possible solutions for measuring silent periods in the unique case of the lower limbs. Finally, we provide comprehensive recommendations for collection, analysis, and reporting of future silent period studies.
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Affiliation(s)
- K E Hupfeld
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - C W Swanson
- Department of Health & Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - B W Fling
- Department of Health & Exercise Science, Colorado State University, Fort Collins, CO, USA; Molecular, Cellular, and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO, USA
| | - R D Seidler
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA; Department of Neurology, University of Florida, Gainesville, FL, USA.
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5
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Ermer E, Harcum S, Lush J, Magder LS, Whitall J, Wittenberg GF, Dimyan MA. Contraction Phase and Force Differentially Change Motor Evoked Potential Recruitment Slope and Interhemispheric Inhibition in Young Versus Old. Front Hum Neurosci 2020; 14:581008. [PMID: 33132888 PMCID: PMC7573560 DOI: 10.3389/fnhum.2020.581008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/15/2020] [Indexed: 11/13/2022] Open
Abstract
Interhemispheric interactions are important for arm coordination and hemispheric specialization. Unilateral voluntary static contraction is known to increase bilateral corticospinal motor evoked potential (MEP) amplitude. It is unknown how increasing and decreasing contraction affect the opposite limb. Since dynamic muscle contraction is more ecologically relevant to daily activities, we studied MEP recruitment using a novel method and short interval interhemispheric inhibition (IHI) from active to resting hemisphere at 4 phases of contralateral ECR contraction: Rest, Ramp Up [increasing at 25% of maximum voluntary contraction (MVC)], Execution (tonic at 50% MVC), and Ramp Down (relaxation at 25% MVC) in 42 healthy adults. We analyzed the linear portion of resting extensor carpi radialis (ECR) MEP recruitment by stimulating at multiple intensities and comparing slopes, expressed as mV per TMS stimulation level, via linear mixed modeling. In younger participants (age ≤ 30), resting ECR MEP recruitment slopes were significantly and equally larger both at Ramp Up (slope increase = 0.047, p < 0.001) and Ramp Down (slope increase = 0.031, p < 0.001) compared to rest, despite opposite directions of force change. In contrast, Active ECR MEP recruitment slopes were larger in Ramp Down than all other phases (Rest:0.184, p < 0.001; Ramp Up:0.128, p = 0.001; Execution: p = 0.003). Older (age ≥ 60) participants’ resting MEP recruitment slope was higher than younger participants across all phases. IHI did not reduce MEP recruitment slope equally in old compared to young. In conclusion, our data indicate that MEP recruitment slope in the resting limb is affected by the homologous active limb contraction force, irrespective of the direction of force change. The active arm MEP recruitment slope, in contrast, remains relatively unaffected. Older participants had steeper MEP recruitment slopes and less interhemispheric inhibition compared to younger participants.
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Affiliation(s)
- Elsa Ermer
- University of Maryland, Baltimore, MD, United States.,Department of Neurology, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
| | - Stacey Harcum
- University of Maryland, Baltimore, MD, United States
| | - Jaime Lush
- University of Maryland, Baltimore, MD, United States.,Department of Neurology, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
| | - Laurence S Magder
- Department of Epidemiology and Public Health, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
| | - Jill Whitall
- University of Maryland, Baltimore, MD, United States.,Department of Physical Therapy and Rehabilitation Science, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
| | - George F Wittenberg
- University of Maryland, Baltimore, MD, United States.,Department of Neurology, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
| | - Michael A Dimyan
- University of Maryland, Baltimore, MD, United States.,Department of Neurology, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States.,Department of Physical Therapy and Rehabilitation Science, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
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6
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Rosso C, Lamy JC. Does Resting Motor Threshold Predict Motor Hand Recovery After Stroke? Front Neurol 2018; 9:1020. [PMID: 30555404 PMCID: PMC6281982 DOI: 10.3389/fneur.2018.01020] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 11/12/2018] [Indexed: 12/15/2022] Open
Abstract
Background: Resting Motor threshold (rMT) is one of the measurement obtained by Transcranial Magnetic Stimulation (TMS) that reflects corticospinal excitability. As a functional marker of the corticospinal pathway, the question arises whether rMT is a suitable biomarker for predicting post-stroke upper limb function. To that aim, we conducted a systematic review of relevant studies that investigated the clinical significance of rMT in stroke survivors by using correlations between upper limb motor scores and rMT. Methods: Studies that reported correlations between upper limb motor function and rMT as a measure of corticospinal excitability in distal arm muscle were identified via a literature search in stroke patients. Two authors extracted the data using a home-made specific form. Subgroup analyses were carried out with patients classified with respect to time post-stroke onset (early vs. chronic stage) and stroke location (cortical, subcortical, or cortico-subcortical). Methodological quality of the study was also evaluated by a published checklist. Results: Eighteen studies with 22 groups (n = 508 stroke patients) were included in this systematic review. Mean methodological quality score was 14.75/24. rMT was often correlated with motor function or hand dexterity (n = 15/22, 68%), explaining on average 31% of the variance of the motor score. Moreover, the results did not seem impacted if patients were examined at the early or chronic stages of stroke. Two findings could not be properly interpreted: (i) the fact that the rMT is an independent predictor of motor function as several confounding factors are well-established, and, (ii) whether the stroke location impacts this prediction. Conclusion: Most of the studies found a correlation between rMT and upper limb motor function after stroke. However, it is still unclear if rMT is an independent predictor of upper limb motor function when taking into account for age, time post stroke onset and level of corticospinal tract damage as confounding factors. Clear-cut conclusions could not be drawn at that time but our results suggest that rMT could be a suitable candidate although future investigations are needed. Systematic Review Registration Number: (https://www.crd.york.ac.uk/prospero/): ID 114317.
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Affiliation(s)
- Charlotte Rosso
- Institut du Cerveau et de la Moelle épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France.,APHP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, Paris, France
| | - Jean-Charles Lamy
- Institut du Cerveau et de la Moelle épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
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7
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Fresnoza S, Christova M, Feil T, Gallasch E, Körner C, Zimmer U, Ischebeck A. The effects of transcranial alternating current stimulation (tACS) at individual alpha peak frequency (iAPF) on motor cortex excitability in young and elderly adults. Exp Brain Res 2018; 236:2573-2588. [PMID: 29943239 PMCID: PMC6153871 DOI: 10.1007/s00221-018-5314-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 06/14/2018] [Indexed: 11/28/2022]
Abstract
Transcranial alternating current stimulation (tACS) can modulate brain oscillations, cortical excitability and behaviour. In aging, the decrease in EEG alpha activity (8–12 Hz) in the parieto-occipital and mu rhythm in the motor cortex are correlated with the decline in cognitive and motor functions, respectively. Increasing alpha activity using tACS might therefore improve cognitive and motor function in the elderly. The present study explored the influence of tACS on cortical excitability in young and old healthy adults. We applied tACS at individual alpha peak frequency for 10 min (1.5 mA) to the left motor cortex. Transcranial magnetic stimulation was used to assess the changes in cortical excitability as measured by motor-evoked potentials at rest, before and after stimulation. TACS increased cortical excitability in both groups. However, our results also suggest that the mechanism behind the effects was different, as we observed an increase and decrease in intracortical inhibition in the old group and young group, respectively. Our results indicate that both groups profited similarly from the stimulation. There was no indication that tACS was more effective in conditions of low alpha power, that is, in the elderly.
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Affiliation(s)
- Shane Fresnoza
- Institute of Psychology, University of Graz, Graz, Austria. .,Institute of Physiology, Medical University of Graz, Graz, Austria.
| | - Monica Christova
- Otto Loewi Research Center, Physiology Section, Medical University of Graz, Graz, Austria.,Department of Physiotherapy, University of Applied Sciences FH-Joanneum Graz, Graz, Austria
| | - Theresa Feil
- Institute of Psychology, University of Graz, Graz, Austria
| | - Eugen Gallasch
- Institute of Physiology, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Christof Körner
- Institute of Psychology, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Ulrike Zimmer
- Institute of Psychology, University of Graz, Graz, Austria.,Faculty of Human Sciences, Medical School Hamburg (MSH), Hamburg, Germany
| | - Anja Ischebeck
- Institute of Psychology, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
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8
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Gomes-Osman J, Indahlastari A, Fried PJ, Cabral DLF, Rice J, Nissim NR, Aksu S, McLaren ME, Woods AJ. Non-invasive Brain Stimulation: Probing Intracortical Circuits and Improving Cognition in the Aging Brain. Front Aging Neurosci 2018; 10:177. [PMID: 29950986 PMCID: PMC6008650 DOI: 10.3389/fnagi.2018.00177] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 05/22/2018] [Indexed: 12/14/2022] Open
Abstract
The impact of cognitive aging on brain function and structure is complex, and the relationship between aging-related structural changes and cognitive function are not fully understood. Physiological and pathological changes to the aging brain are highly variable, making it difficult to estimate a cognitive trajectory with which to monitor the conversion to cognitive decline. Beyond the information on the structural and functional consequences of cognitive aging gained from brain imaging and neuropsychological studies, non-invasive brain stimulation techniques such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) can enable stimulation of the human brain in vivo, offering useful insights into the functional integrity of intracortical circuits using electrophysiology and neuromodulation. TMS measurements can be used to identify and monitor changes in cortical reactivity, the integrity of inhibitory and excitatory intracortical circuits, the mechanisms of long-term potentiation (LTP)/depression-like plasticity and central cholinergic function. Repetitive TMS and tDCS can be used to modulate neuronal excitability and enhance cortical function, and thus offer a potential means to slow or reverse cognitive decline. This review will summarize and critically appraise relevant literature regarding the use of TMS and tDCS to probe cortical areas affected by the aging brain, and as potential therapeutic tools to improve cognitive function in the aging population. Challenges arising from intra-individual differences, limited reproducibility, and methodological differences will be discussed.
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Affiliation(s)
- Joyce Gomes-Osman
- Department of Physical Therapy, University of Miami Miller School of Medicine, Miami, FL, United States
- Evelyn F. McKnight Brain Institute, University of Miami Miller School of Medicine, Miami, FL, United States
- Berenson-Allen Center for Noninvasive Brain Stimulation, Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Aprinda Indahlastari
- Department of Clinical and Health Psychology, Department of Neuroscience, Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Peter J. Fried
- Berenson-Allen Center for Noninvasive Brain Stimulation, Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Danylo L. F. Cabral
- Department of Physical Therapy, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Jordyn Rice
- Department of Physical Therapy, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Nicole R. Nissim
- Department of Clinical and Health Psychology, Department of Neuroscience, Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Serkan Aksu
- Department of Clinical and Health Psychology, Department of Neuroscience, Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Molly E. McLaren
- Department of Clinical and Health Psychology, Department of Neuroscience, Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Adam J. Woods
- Department of Clinical and Health Psychology, Department of Neuroscience, Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
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9
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Rosso C, Perlbarg V, Valabregue R, Obadia M, Kemlin-Méchin C, Moulton E, Leder S, Meunier S, Lamy JC. Anatomical and functional correlates of cortical motor threshold of the dominant hand. Brain Stimul 2017; 10:952-958. [PMID: 28551318 DOI: 10.1016/j.brs.2017.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/04/2017] [Accepted: 05/15/2017] [Indexed: 10/19/2022] Open
Abstract
BACKGROUND Resting Motor threshold (rMT) provides information about cortical motor excitability. Interestingly, the influences of the structural or functional variability of the motor system on the rMT inter-individual variability have been poorly investigated. OBJECTIVE/HYPOTHESIS To investigate relationships between rMT and measures of brain structures and function of the motor system. The hypothesis is that cortical excitability not only depends on the primary motor cortex (M1) but also on the integration of information originating from its vicinity such as premotor (PMd and SMA) and post-central (S1) cortices. METHODS We measured brain structures, including grey and white matter properties (cortical volume and fiber coherence respectively), and functional interaction (resting-state functional connectivity-FC) in areas contributing to the corticospinal tract axons, i. e, M1, S1, SMA and PMd in the dominant hemisphere of 21 healthy subjects. RESULTS The rMT was inversely correlated with the FC between PMd and M1 (r = -0.496, 95%CI: -0.764; -0.081; p = 0.02) and the grey matter volume of the dominant hemisphere (r = -0.463, 95%CI: -0.746; -0.039; p = 0.03). The multiple regression analysis model retained the FC between M1 and PMd (coefficient: -25 ± 9) as well as the grey matter volume of the dominant hemisphere (coefficient: -0.15 ± 0.06) explaining 44% of the variance of the rMT (p: 0.005). When adding age and coil-to-cortex distance, two factors known to influence rMT, the model reached a R2 of 75% (p: 0.0001). CONCLUSIONS These results underline the major role of the PMd and the cortico-cortical connections toward M1 in the excitation of the corticospinal fibers likely through trans-synaptic pathways.
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Affiliation(s)
- Charlotte Rosso
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France; AP-HP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, F-75013, Paris, France.
| | - Vincent Perlbarg
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, Laboratoire d'imagerie biomédicale (LIB), F-75013, Paris, France; Bioinformatics and Biostatistics Core Facility, iCONICS, IHU-A-ICM, Institut du Cerveau et de la Moelle épinière, Paris, France
| | - Romain Valabregue
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France; Centre de Neuro-imagerie de Recherche, CENIR, F-75013, Paris, France
| | - Mickaël Obadia
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France; AP-HP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Claire Kemlin-Méchin
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Eric Moulton
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Sara Leder
- AP-HP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Sabine Meunier
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Jean-Charles Lamy
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France; Centre de Neuro-imagerie de Recherche, CENIR, F-75013, Paris, France
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10
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Chen M, Summers RLS, Goding GS, Samargia S, Ludlow CL, Prudente CN, Kimberley TJ. Evaluation of the Cortical Silent Period of the Laryngeal Motor Cortex in Healthy Individuals. Front Neurosci 2017; 11:88. [PMID: 28326007 PMCID: PMC5339278 DOI: 10.3389/fnins.2017.00088] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 02/10/2017] [Indexed: 11/13/2022] Open
Abstract
Objective: This work aimed to evaluate the cortical silent period (cSP) of the laryngeal motor cortex (LMC) using the bilateral thyroarytenoid (TA) muscles with transcranial magnetic stimulation (TMS). Methods: In 11 healthy participants, fine-wire electromyography (EMG) was used to record bilateral TA muscle responses to single pulse TMS delivered to the LMC in both hemispheres. Peripheral responses to stimulation over the mastoid, where the vagus nerve exits the skull, were collected to verify the central origin of the cortical stimulation responses by comparing the latencies. Results: The cSP duration ranged from 41.7 to 66.4 ms. The peripherally evoked motor-evoked potential (MEP) peak occurred 5–9 ms earlier than the cortical responses (for both sides of TAs: p < 0.0001) with no silent period. The right TA MEP latencies were earlier than the left TA responses for both peripheral and cortical measures (p ≤ 0.0001). Conclusion: These findings demonstrate the feasibility of measuring cSP of LMC based on intrinsic laryngeal muscles responses during vocalization in healthy volunteers. Significance: The technique could be used to study the pathophysiology of neurological disorders that affect TA muscles, such as spasmodic dysphonia. Further, the methodology has application to other muscles of the head and neck not accessible using surface electrodes.
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Affiliation(s)
- Mo Chen
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota Minneapolis, MN, USA
| | - Rebekah L S Summers
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota Minneapolis, MN, USA
| | - George S Goding
- Department of Otolaryngology-Head and Neck Surgery, University of Minnesota Minneapolis, MN, USA
| | - Sharyl Samargia
- Department of Communication Sciences and Disorders, University of Wisconsin River Falls Campus River Falls, WI, USA
| | - Christy L Ludlow
- Department of Communication Sciences and Disorders, James Madison University Harrisonburg, VA, USA
| | - Cecília N Prudente
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota Minneapolis, MN, USA
| | - Teresa J Kimberley
- Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota Minneapolis, MN, USA
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11
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Yarnall A, Ho B, Eshun E, David R, Rochester L, Burn D, Baker M. Short latency afferent inhibition: Effects of ageing. Clin Neurophysiol 2016; 127:2410-3. [DOI: 10.1016/j.clinph.2016.03.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/06/2016] [Accepted: 03/09/2016] [Indexed: 11/25/2022]
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12
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Cueva AS, Galhardoni R, Cury RG, Parravano DC, Correa G, Araujo H, Cecilio SB, Raicher I, Toledo D, Silva V, Marcolin MA, Teixeira MJ, Ciampi de Andrade D. Normative data of cortical excitability measurements obtained by transcranial magnetic stimulation in healthy subjects. Neurophysiol Clin 2016; 46:43-51. [DOI: 10.1016/j.neucli.2015.12.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 11/23/2015] [Accepted: 12/29/2015] [Indexed: 10/22/2022] Open
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13
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Ziemann U, Reis J, Schwenkreis P, Rosanova M, Strafella A, Badawy R, Müller-Dahlhaus F. TMS and drugs revisited 2014. Clin Neurophysiol 2014; 126:1847-68. [PMID: 25534482 DOI: 10.1016/j.clinph.2014.08.028] [Citation(s) in RCA: 450] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Revised: 08/03/2014] [Accepted: 08/24/2014] [Indexed: 12/18/2022]
Abstract
The combination of pharmacology and transcranial magnetic stimulation to study the effects of drugs on TMS-evoked EMG responses (pharmaco-TMS-EMG) has considerably improved our understanding of the effects of TMS on the human brain. Ten years have elapsed since an influential review on this topic has been published in this journal (Ziemann, 2004). Since then, several major developments have taken place: TMS has been combined with EEG to measure TMS evoked responses directly from brain activity rather than by motor evoked potentials in a muscle, and pharmacological characterization of the TMS-evoked EEG potentials, although still in its infancy, has started (pharmaco-TMS-EEG). Furthermore, the knowledge from pharmaco-TMS-EMG that has been primarily obtained in healthy subjects is now applied to clinical settings, for instance, to monitor or even predict clinical drug responses in neurological or psychiatric patients. Finally, pharmaco-TMS-EMG has been applied to understand the effects of CNS active drugs on non-invasive brain stimulation induced long-term potentiation-like and long-term depression-like plasticity. This is a new field that may help to develop rationales of pharmacological treatment for enhancement of recovery and re-learning after CNS lesions. This up-dated review will highlight important knowledge and recent advances in the contribution of pharmaco-TMS-EMG and pharmaco-TMS-EEG to our understanding of normal and dysfunctional excitability, connectivity and plasticity of the human brain.
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Affiliation(s)
- Ulf Ziemann
- Department of Neurology & Stroke, and Hertie Institute for Clinical Brain Research, Eberhard-Karls-University Tübingen, Tübingen, Germany.
| | - Janine Reis
- Department of Neurology, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Peter Schwenkreis
- Department of Neurology, BG-University Hospital Bergmannsheil Bochum, Bochum, Germany
| | - Mario Rosanova
- Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy; Fondazione Europea di Ricerca Biomedica, FERB Onlus, Milan, Italy
| | - Antonio Strafella
- Morton and Gloria Shulman Movement Disorder Unit & E.J. Safra Parkinson Disease Program, Toronto Western Hospital, UHN, University of Toronto, Ontario, Canada; Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Ontario, Canada
| | - Radwa Badawy
- Department of Neurology, Saint Vincent's Hospital, Fitzroy, The University of Melbourne, Parkville, Victoria, Australia; Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
| | - Florian Müller-Dahlhaus
- Department of Neurology & Stroke, and Hertie Institute for Clinical Brain Research, Eberhard-Karls-University Tübingen, Tübingen, Germany
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14
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Transcranial magnetic stimulation for the treatment of pharmacoresistant nondelusional auditory verbal hallucinations in dementia. Case Rep Psychiatry 2013; 2013:930304. [PMID: 24198993 PMCID: PMC3808098 DOI: 10.1155/2013/930304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 09/15/2013] [Indexed: 11/17/2022] Open
Abstract
Auditory verbal hallucinations (AVHs) are known as a core symptom of schizophrenia, but also occur in a number of other conditions, not least in neurodegenerative disorders such as dementia. In the last decades, Transcranial Magnetic Stimulation (TMS) emerged as a valuable therapeutic approach towards several neurological and psychiatric diseases, including AVHs. Herein we report a case of a seventy-six-years-old woman with vascular-degenerative brain disease, complaining of threatening AVHs. The patient was treated with a high-frequency temporoparietal (T3P3) rTMS protocol for fifteen days. A considerable reduction of AVHs in frequency and content (no more threatening) was observed. Although further research is needed, this seems an encouraging result.
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15
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Relationship between excitability, plasticity and thickness of the motor cortex in older adults. Neuroimage 2013; 83:809-16. [PMID: 23876242 DOI: 10.1016/j.neuroimage.2013.07.033] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 07/07/2013] [Accepted: 07/10/2013] [Indexed: 02/06/2023] Open
Abstract
The relationship between brain structure, cortical physiology, and learning ability in older adults is of particular interest in understanding mechanisms of age-related cognitive decline. Only a few studies addressed this issue so far, yielding mixed results. Here, we used comprehensive multiple regression analyses to investigate associations between brain structure on the one hand, i.e., cortical thickness (CT), fractional anisotropy (FA) of the pyramidal tract and individual coil-to-cortex distance, and cortical physiology on the other hand, i.e. motor cortex excitability and long-term potentiation (LTP)-like cortical plasticity, in healthy older adults (mean age 64 years, 14 women). Additional exploratory analyses assessed correlations between cortical physiology and learning ability in the verbal domain. In the regression models, we found that cortical excitability could be best predicted by CT of the hand knob of the primary motor cortex (CT-M1HAND) and individual coil-to-cortex distance, while LTP-like cortical plasticity was predicted by CT-M1HAND and FA of the pyramidal tract. Exploratory analyses revealed a significant inverse correlation between cortical excitability and learning ability. In conclusion, higher cortical excitability was associated with lower CT and lower learning ability in a cohort of healthy older adults, in line with previous reports of increased cortical excitability in patients with cortical atrophy and cognitive deficits due to Alzheimer's Disease. Cortical excitability may thus be a parameter to identify individuals at risk for cognitive decline and gray matter atrophy, a hypothesis to be explored in future longitudinal studies.
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16
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Ziemann U. Pharmaco-transcranial magnetic stimulation studies of motor excitability. HANDBOOK OF CLINICAL NEUROLOGY 2013; 116:387-397. [PMID: 24112911 DOI: 10.1016/b978-0-444-53497-2.00032-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Application of a single dose of a central nervous system (CNS) active drug with a defined single mode of action has been proven useful to explore and characterize the pharmacophysiological properties of transcranial magnetic stimulation (TMS) measures of motor cortical and corticospinal excitability in humans. With this pharmaco-TMS approach, it was demonstrated that different TMS measures reflect axon excitability (motor threshold), or inhibitory (cortical silent period, short-interval intracortical inhibition, long-interval intracortical inhibition, short-latency afferent inhibition) or excitatory synaptic excitability (motor evoked potential amplitude, intracortical facilitation, short-interval intracortical facilitation) of distinct neuronal elements in the CNS. Pharmaco-TMS has opened an exciting window into human cortical physiology. The array of pharmacophysiologically well defined TMS measures is now used by neurologists, psychiatrists, and clinical neurophysiologists for diagnosis or treatment monitoring in neuropsychiatric disease. This chapter reviews systematically the TMS measures of motor cortical and corticospinal excitability from the perspective of pharmacophysiological characterization. For example, it is demonstrated that blockers of voltage-gated sodium channels specifically increase motor threshold but do not alter other TMS measures of excitability, whereas positive modulators at γ-butyric acid (GABA) type A receptors, such as benzodiazepines, enhance short-interval intracortical inhibition and depress motor evoked potential amplitude but have no effect on motor threshold.
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Affiliation(s)
- Ulf Ziemann
- Department of Neurology and Stroke, Hertie Institute for Clinical Brain Research, Eberhard-Karls University Tübingen, Tübingen, Germany.
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17
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Niskanen E, Könönen M, Määttä S, Hallikainen M, Kivipelto M, Casarotto S, Massimini M, Vanninen R, Mervaala E, Karhu J, Soininen H. New insights into Alzheimer's disease progression: a combined TMS and structural MRI study. PLoS One 2011; 6:e26113. [PMID: 22022529 PMCID: PMC3192142 DOI: 10.1371/journal.pone.0026113] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 09/19/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Combination of structural and functional data of the human brain can provide detailed information of neurodegenerative diseases and the influence of the disease on various local cortical areas. METHODOLOGY AND PRINCIPAL FINDINGS To examine the relationship between structure and function of the brain the cortical thickness based on structural magnetic resonance images and motor cortex excitability assessed with transcranial magnetic stimulation were correlated in Alzheimer's disease (AD) and mild cognitive impairment (MCI) patients as well as in age-matched healthy controls. Motor cortex excitability correlated negatively with cortical thickness on the sensorimotor cortex, the precuneus and the cuneus but the strength of the correlation varied between the study groups. On the sensorimotor cortex the correlation was significant only in MCI subjects. On the precuneus and cuneus the correlation was significant both in AD and MCI subjects. In healthy controls the motor cortex excitability did not correlate with the cortical thickness. CONCLUSIONS In healthy subjects the motor cortex excitability is not dependent on the cortical thickness, whereas in neurodegenerative diseases the cortical thinning is related to weaker cortical excitability, especially on the precuneus and cuneus. However, in AD subjects there seems to be a protective mechanism of hyperexcitability on the sensorimotor cortex counteracting the prominent loss of cortical volume since the motor cortex excitability did not correlate with the cortical thickness. Such protective mechanism was not found on the precuneus or cuneus nor in the MCI subjects. Therefore, our results indicate that the progression of the disease proceeds with different dynamics in the structure and function of neuronal circuits from normal conditions via MCI to AD.
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Affiliation(s)
- Eini Niskanen
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
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18
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Bella R, Ferri R, Pennisi M, Cantone M, Lanza G, Malaguarnera G, Spampinato C, Giordano D, Alagona G, Pennisi G. Enhanced motor cortex facilitation in patients with vascular cognitive impairment-no dementia. Neurosci Lett 2011; 503:171-5. [PMID: 21875648 DOI: 10.1016/j.neulet.2011.08.022] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 07/25/2011] [Accepted: 08/12/2011] [Indexed: 02/07/2023]
Abstract
Data on Transcranial Magnetic Stimulation (TMS) derived measures of cortical excitability and intracortical circuits in age-related white matter changes are scarce. We aimed to assess early changes of motor cortex excitability in nondemented elderly patients with subcortical ischemic vascular disease (SVD). Ten SVD elderly and ten age-matched controls underwent paired-pulse TMS for the analysis of intracortical inhibition (ICI) and facilitation (ICF). All subjects performed neuropsychological assessment and brain magnetic resonance imaging. SVD patients showed abnormal executive control function. No statistically significant differences were found for resting motor threshold, cortical silent period between SVD patients and controls or between the two hemispheres, in patients. A significant enhancement of mean ICF was observed in SVD patients. This study provides the first evidence of functional changes in intracortical excitatory neuronal circuits in patients with SVD and clinical features of vascular cognitive impairment-no dementia. Further studies are required to evaluate whether the observed change of ICF might predict cognitive and/or motor impairment in a population at risk for subcortical vascular dementia.
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Affiliation(s)
- Rita Bella
- Department GF Ingrassia, Section of Neurosciences, University of Catania, Via Santa Sofia, 78, 95123 Catania, Italy
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19
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Bernard JA, Seidler RD. Evidence for motor cortex dedifferentiation in older adults. Neurobiol Aging 2011; 33:1890-9. [PMID: 21813213 DOI: 10.1016/j.neurobiolaging.2011.06.021] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 05/26/2011] [Accepted: 06/21/2011] [Indexed: 11/29/2022]
Abstract
Older adults (OA) show more diffuse brain activity than young adults (YA) during the performance of cognitive, motor, and perceptual tasks. It is unclear whether this overactivation reflects compensation or dedifferentiation. Typically, these investigations have not evaluated the organization of the resting brain, which can help to determine whether more diffuse representations reflect physiological or task-dependent effects. In the present study we used transcranial magnetic stimulation (TMS) to determine whether there are differences in motor cortex organization of both brain hemispheres in young and older adults. We measured resting motor threshold, motor evoked potential (MEP) latency and amplitude, and extent of first dorsal interosseous representations, in addition to a computerized measure of reaction time. There was no significant age difference in motor threshold, but we did find that OA had larger contralateral MEP amplitudes and a longer contralateral MEP latency. Furthermore, the spatial extent of motor representations in OA was larger. We found that larger dominant hemisphere motor representations in OA were associated with higher reaction times, suggesting dedifferentiation rather than compensation effects.
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Affiliation(s)
- Jessica A Bernard
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109-1043, USA.
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20
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Age-related changes in short-latency motor cortex inhibition. Exp Brain Res 2009; 198:489-500. [PMID: 19618169 DOI: 10.1007/s00221-009-1945-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Accepted: 07/03/2009] [Indexed: 01/17/2023]
Abstract
This study examined whether short-latency intracortical inhibition (SICI) and/or facilitation (ICF) changes with ageing, and if this can be attributed to age-related changes in the inhibition and/or corticospinal stimulus-response curves. SICI/ICF was studied in 17 "old" (63.1 +/- 4.2 years) and 13 "young" males (20.0 +/- 2.0 years) in both hemispheres using a paired-pulse transcranial magnetic stimulation paradigm at four interstimulus intervals (1, 3, 10 and 12 ms). Motor-evoked potentials were recorded from the first dorsal interosseous muscle at rest, with a conditioning intensity set at 5% stimulator output below the active threshold (aMT). Regardless of age, SICI was greater in the left compared with the right hemisphere. SICI was increased in old men at 3 ms in the left hemisphere and at 1 ms in the in both hemispheres, but ICF was not altered. However, aMT, and hence the conditioning stimulus intensity, was higher in old men. Comparisons of pairs of young and old men with the same aMT, and of SICI curves constructed relative to aMT, failed to show any age-related increase in SICI, although age-related changes in aMT accounted for less than 20% of the variability. Corticospinal stimulus-response characteristics did not influence SICI/ICF and appear not to be altered by ageing in men. When measured in resting muscles, SICI/ICF appears unaltered by age. But it remains unknown if, when assessed during movement preparation or movement, there are changes in SICI related to functional motor changes commonly associated with ageing, such as slowing of movement.
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21
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Siebner HR, Bergmann TO, Bestmann S, Massimini M, Johansen-Berg H, Mochizuki H, Bohning DE, Boorman ED, Groppa S, Miniussi C, Pascual-Leone A, Huber R, Taylor PCJ, Ilmoniemi RJ, De Gennaro L, Strafella AP, Kähkönen S, Klöppel S, Frisoni GB, George MS, Hallett M, Brandt SA, Rushworth MF, Ziemann U, Rothwell JC, Ward N, Cohen LG, Baudewig J, Paus T, Ugawa Y, Rossini PM. Consensus paper: combining transcranial stimulation with neuroimaging. Brain Stimul 2009; 2:58-80. [PMID: 20633405 DOI: 10.1016/j.brs.2008.11.002] [Citation(s) in RCA: 223] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 11/30/2008] [Indexed: 02/05/2023] Open
Abstract
In the last decade, combined transcranial magnetic stimulation (TMS)-neuroimaging studies have greatly stimulated research in the field of TMS and neuroimaging. Here, we review how TMS can be combined with various neuroimaging techniques to investigate human brain function. When applied during neuroimaging (online approach), TMS can be used to test how focal cortex stimulation acutely modifies the activity and connectivity in the stimulated neuronal circuits. TMS and neuroimaging can also be separated in time (offline approach). A conditioning session of repetitive TMS (rTMS) may be used to induce rapid reorganization in functional brain networks. The temporospatial patterns of TMS-induced reorganization can be subsequently mapped by using neuroimaging methods. Alternatively, neuroimaging may be performed first to localize brain areas that are involved in a given task. The temporospatial information obtained by neuroimaging can be used to define the optimal site and time point of stimulation in a subsequent experiment in which TMS is used to probe the functional contribution of the stimulated area to a specific task. In this review, we first address some general methodologic issues that need to be taken into account when using TMS in the context of neuroimaging. We then discuss the use of specific brain mapping techniques in conjunction with TMS. We emphasize that the various neuroimaging techniques offer complementary information and have different methodologic strengths and weaknesses.
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Affiliation(s)
- Hartwig R Siebner
- Danish Research Center for Magnetic Resonance, Copenhagen University Hospital-Hvidovre, Denmark; Department of Neurology, Christian-Albrechts-University, Kiel, Germany.
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22
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Motor Potentials Evoked by Navigated Transcranial Magnetic Stimulation in Healthy Subjects. J Clin Neurophysiol 2008; 25:367-72. [DOI: 10.1097/wnp.0b013e31818e7944] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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23
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Yoon T, De-Lap BS, Griffith EE, Hunter SK. Age-related muscle fatigue after a low-force fatiguing contraction is explained by central fatigue. Muscle Nerve 2008; 37:457-66. [PMID: 18236468 DOI: 10.1002/mus.20969] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The contribution of central fatigue during and after low- and high-force isometric contractions sustained until failure with age is not established. We compared the time to failure and changes in voluntary activation measured using motor point stimulation of 15 young and 15 old adults for an isometric contraction sustained with the elbow flexor muscles at 20% and 80% of maximal voluntary contraction (MVC) force. Young adults had a briefer time to task failure than old adults for the 20% MVC fatiguing contraction, but a similar duration for the 80% task. Voluntary activation was reduced at the end of the 20% MVC task, but by greater magnitudes for old than young adults. The reduction in MVC torque after the low-force task was associated with the reduction in voluntary activation. After the 80% task, voluntary activation declined to similar levels for the young and old adults. Electromyographic activity levels (% MVC) of the biceps brachii and brachioradialis muscles during the fatiguing contraction were greater for the old than young for the 20% MVC task, but similar with age for the 80% MVC task. Our findings indicate that intensity and duration of contraction can be manipulated in young and old adults to induce varying magnitudes of fatigue within the central nervous system. Aging increases: (1) fatigue within the central nervous system immediately after a low-force fatiguing contraction, and (2) the potential for large neural adaptations during neuromuscular rehabilitation in old adults.
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Affiliation(s)
- Tejin Yoon
- Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, WI 53201, USA
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24
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Bozzali M, Cercignani M, Caltagirone C. Brain volumetrics to investigate aging and the principal forms of degenerative cognitive decline: a brief review. Magn Reson Imaging 2008; 26:1065-70. [PMID: 18436405 DOI: 10.1016/j.mri.2008.01.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 01/14/2008] [Indexed: 11/30/2022]
Abstract
The volume of the brain and of some of its structures can provide insight into the pathological process of several diseases. For this reason, in the recent years we saw a tremendous progress in the development of automated techniques for gaining information about global and regional atrophy. This paper reviews the main methods of analysis to quantify brain volume, and their application to the study of normal aging and the principal forms of degenerative dementias.
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Affiliation(s)
- Marco Bozzali
- Neuroimaging Laboratory, Santa Lucia Foundation, IRCSS, Rome, Italy.
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25
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Tecchio F, Zappasodi F, Pasqualetti P, Gennaro LD, Pellicciari MC, Ercolani M, Squitti R, Rossini PM. Age dependence of primary motor cortex plasticity induced by paired associative stimulation. Clin Neurophysiol 2008; 119:675-682. [PMID: 18178522 DOI: 10.1016/j.clinph.2007.10.023] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Revised: 09/26/2007] [Accepted: 10/31/2007] [Indexed: 02/05/2023]
Affiliation(s)
- F Tecchio
- ISTC-CNR, Franca Tecchio, Unità MEG, Fatebenefratelli Hospital, Isola Tiberina, 00186 Roma, Italy; Casa di Cura San Raffaele Cassino e IRCCS San Raffaele Pisana, Italy.
| | - F Zappasodi
- ISTC-CNR, Franca Tecchio, Unità MEG, Fatebenefratelli Hospital, Isola Tiberina, 00186 Roma, Italy; AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy
| | - P Pasqualetti
- AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy; Casa di Cura San Raffaele Cassino e IRCCS San Raffaele Pisana, Italy
| | - L De Gennaro
- Department of Psychology, University 'Sapienza', Roma, Italy
| | - M C Pellicciari
- Cognitive Neuroscience Unit, IRCCS "Centro San Giovanni di Dio - FBF", Brescia, Italy
| | - M Ercolani
- AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy
| | - R Squitti
- AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy
| | - P M Rossini
- Department of Neurology, 'Campus Bio-Medico' University, Roma, Italy; AFaR, Fatebenefratelli Hospital, Isola Tiberina, Roma, Italy; Cognitive Neuroscience Unit, IRCCS "Centro San Giovanni di Dio - FBF", Brescia, Italy
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