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Gunduz A, Valls-Solé J, Serranová T, Coppola G, Kofler M, Jääskeläinen SK. The blink reflex and its modulation - Part 2: Pathophysiology and clinical utility. Clin Neurophysiol 2024; 160:75-94. [PMID: 38412746 DOI: 10.1016/j.clinph.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 12/30/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024]
Abstract
The blink reflex (BR) is integrated at the brainstem; however, it is modulated by inputs from various structures such as the striatum, globus pallidus, substantia nigra, and nucleus raphe magnus but also from afferent input from the peripheral nervous system. Therefore, it provides information about the pathophysiology of numerous peripheral and central nervous system disorders. The BR is a valuable tool for studying the integrity of the trigemino-facial system, the relevant brainstem nuclei, and circuits. At the same time, some neurophysiological techniques applying the BR may indicate abnormalities involving structures rostral to the brainstem that modulate or control the BR circuits. This is a state-of-the-art review of the clinical application of BR modulation; physiology is reviewed in part 1. In this review, we aim to present the role of the BR and techniques related to its modulation in understanding pathophysiological mechanisms of motor control and pain disorders, in which these techniques are diagnostically helpful. Furthermore, some BR techniques may have a predictive value or serve as a basis for follow-up evaluation. BR testing may benefit in the diagnosis of hemifacial spasm, dystonia, functional movement disorders, migraine, orofacial pain, and psychiatric disorders. Although the abnormalities in the integrity of the BR pathway itself may provide information about trigeminal or facial nerve disorders, alterations in BR excitability are found in several disease conditions. BR excitability studies are suitable for understanding the common pathophysiological mechanisms behind various clinical entities, elucidating alterations in top-down inhibitory systems, and allowing for follow-up and quantitation of many neurological syndromes.
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Affiliation(s)
- Aysegul Gunduz
- Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Department of Neurology, Division of Neurophysiology, Istanbul, Turkey.
| | - Josep Valls-Solé
- IDIBAPS. Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villarroel 170 08024, Barcelona, Spain.
| | - Tereza Serranová
- Department of Neurology and Center of Clinical Neuroscience, Charles University, Prague 1st Faculty of Medicine and General University Hospital, Prague, Kateřinská 30, 12800 Prague 2, Czech Republic.
| | - Gianluca Coppola
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome Polo Pontino ICOT, via Franco Faggiana 1668 04100, Latina, Italy.
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, A-6170 Zirl, Austria.
| | - Satu K Jääskeläinen
- Department of Clinical Neurophysiology, Division of Medical Imaging, Turku University Hospital and University of Turku, Postal Box 52, FIN 20521 Turku, Finland.
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Edwards M, Koens L, Liepert J, Nonnekes J, Schwingenschuh P, van de Stouwe A, Morgante F. Clinical neurophysiology of functional motor disorders: IFCN Handbook Chapter. Clin Neurophysiol Pract 2024; 9:69-77. [PMID: 38352251 PMCID: PMC10862411 DOI: 10.1016/j.cnp.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/18/2023] [Accepted: 12/27/2023] [Indexed: 02/16/2024] Open
Abstract
Functional Motor Disorders are common and disabling. Clinical diagnosis has moved from one of exclusion of other causes for symptoms to one where positive clinical features on history and examination are used to make a "rule in" diagnosis wherever possible. Clinical neurophysiological assessments have developed increasing importance in assisting with this positive diagnosis, not being used simply to demonstrate normal sensory-motor pathways, but instead to demonstrate specific abnormalities that help to positively diagnose these disorders. Here we provide a practical review of these techniques, their application, interpretation and pitfalls. We also highlight particular areas where such tests are currently lacking in sensitivity and specificity, for example in people with functional dystonia and functional tic-like movements.
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Affiliation(s)
- M.J. Edwards
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, UK
- Department of Neuropsychiatry, Maudsley Hospital, London, UK
| | - L.H. Koens
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Department of Neurology and Clinical Neurophysiology, Martini Ziekenhuis, Groningen, the Netherlands
| | - J. Liepert
- Kliniken Schmieder Allensbach, Allensbach, Germany
| | - J. Nonnekes
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
- Center of Expertise for Parkinson & Movement Disorders, Department of Rehabilitation, Nijmegen, the Netherlands
- Department of Rehabilitation, Sint Maartenskliniek, Ubbergen, the Netherlands
| | | | - A.M.M. van de Stouwe
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Department of Neurology, Ommelander Ziekenhuis, Scheemda, the Netherlands
| | - F. Morgante
- Neurosciences Research Centre, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
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Ordás CM, Alonso-Frech F. The neural basis of somatosensory temporal discrimination threshold as a paradigm for time processing in the sub-second range: An updated review. Neurosci Biobehav Rev 2024; 156:105486. [PMID: 38040074 DOI: 10.1016/j.neubiorev.2023.105486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 11/20/2023] [Accepted: 11/27/2023] [Indexed: 12/03/2023]
Abstract
BACKGROUND AND OBJECTIVE The temporal aspect of somesthesia is a feature of any somatosensory process and a pre-requisite for the elaboration of proper behavior. Time processing in the milliseconds range is crucial for most of behaviors in everyday life. The somatosensory temporal discrimination threshold (STDT) is the ability to perceive two successive stimuli as separate in time, and deals with time processing in this temporal range. Herein, we focus on the physiology of STDT, on a background of the anatomophysiology of somesthesia and the neurobiological substrates of timing. METHODS A review of the literature through PubMed & Cochrane databases until March 2023 was performed with inclusion and exclusion criteria following PRISMA recommendations. RESULTS 1151 abstracts were identified. 4 duplicate records were discarded before screening. 957 abstracts were excluded because of redundancy, less relevant content or not English-written. 4 were added after revision. Eventually, 194 articles were included. CONCLUSIONS STDT encoding relies on intracortical inhibitory S1 function and is modulated by the basal ganglia-thalamic-cortical interplay through circuits involving the nigrostriatal dopaminergic pathway and probably the superior colliculus.
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Affiliation(s)
- Carlos M Ordás
- Universidad Rey Juan Carlos, Móstoles, Madrid, Spain; Department of Neurology, Hospital Rey Juan Carlos, Móstoles, Madrid, Spain.
| | - Fernando Alonso-Frech
- Department of Neurology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Spain
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Weissbach A, Moyé J, Takacs A, Verrel J, Chwolka F, Friedrich J, Paulus T, Zittel S, Bäumer T, Frings C, Pastötter B, Beste C, Münchau A. Perception-Action Integration Is Altered in Functional Movement Disorders. Mov Disord 2023; 38:1399-1409. [PMID: 37315159 DOI: 10.1002/mds.29458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 04/25/2023] [Accepted: 05/12/2023] [Indexed: 06/16/2023] Open
Abstract
BACKGROUND Although functional neurological movement disorders (FMD) are characterized by motor symptoms, sensory processing has also been shown to be disturbed. However, how the integration of perception and motor processes, essential for the control of goal-directed behavior, is altered in patients with FMD is less clear. A detailed investigation of these processes is crucial to foster a better understanding of the pathophysiology of FMD and can systematically be achieved in the framework of the theory of event coding (TEC). OBJECTIVE The aim was to investigate perception-action integration processes on a behavioral and neurophysiological level in patients with FMD. METHODS A total of 21 patients and 21 controls were investigated with a TEC-related task, including concomitant electroencephalogram (EEG) recording. We focused on EEG correlates established to reflect perception-action integration processes. Temporal decomposition allowed to distinguish between EEG codes reflecting sensory (S-cluster), motor (R-cluster), and integrated sensory-motor processing (C-cluster). We also applied source localization analyses. RESULTS Behaviorally, patients revealed stronger binding between perception and action, as evidenced by difficulties in reconfiguring previously established stimulus-response associations. Such hyperbinding was paralleled by a modulation of neuronal activity clusters, including reduced C-cluster modulations of the inferior parietal cortex and altered R-cluster modulations in the inferior frontal gyrus. Correlations of these modulations with symptom severity were also evident. CONCLUSIONS Our study shows that FMD is characterized by altered integration of sensory information with motor processes. Relations between clinical severity and both behavioral performance and neurophysiological abnormalities indicate that perception-action integration processes are central and a promising concept for the understanding of FMD. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Anne Weissbach
- Institute of Systems Motor Science, Center of Brain, Behavior, and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Josephine Moyé
- Institute of Systems Motor Science, Center of Brain, Behavior, and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Adam Takacs
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Julius Verrel
- Institute of Systems Motor Science, Center of Brain, Behavior, and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Fabian Chwolka
- Institute of Systems Motor Science, Center of Brain, Behavior, and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Julia Friedrich
- Institute of Systems Motor Science, Center of Brain, Behavior, and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Theresa Paulus
- Institute of Systems Motor Science, Center of Brain, Behavior, and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
- Department of Neurology, University of Lübeck, Lübeck, Germany
| | - Simone Zittel
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias Bäumer
- Institute of Systems Motor Science, Center of Brain, Behavior, and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Christian Frings
- Department of Cognitive Psychology, Trier University Trier, Trier, Germany
| | - Bernhard Pastötter
- Department of Cognitive Psychology, Trier University Trier, Trier, Germany
| | - Christian Beste
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Alexander Münchau
- Institute of Systems Motor Science, Center of Brain, Behavior, and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
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Fischer P, Piña-Fuentes D, Kassavetis P, Sadnicka A. Physiology of dystonia: Human studies. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 169:137-162. [PMID: 37482391 DOI: 10.1016/bs.irn.2023.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
In this chapter, we discuss neurophysiological techniques that have been used in the study of dystonia. We examine traditional disease models such as inhibition and excessive plasticity and review the evidence that these play a causal role in pathophysiology. We then review the evidence for sensory and peripheral influences within pathophysiology and look at an emergent literature that tries to probe how oscillatory brain activity may be linked to dystonia pathophysiology.
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Affiliation(s)
- Petra Fischer
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Dan Piña-Fuentes
- Department of Neurology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, The Netherlands; Department of Neurology, OLVG, Amsterdam, The Netherlands
| | | | - Anna Sadnicka
- Motor Control and Movement Disorders Group, St George's University of London, London, United Kingdom; Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom.
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Ricciardi L, Bologna M, Marsili L, Espay AJ. Dysfunctional Networks in Functional Dystonia. ADVANCES IN NEUROBIOLOGY 2023; 31:157-176. [PMID: 37338701 DOI: 10.1007/978-3-031-26220-3_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
Functional dystonia, the second most common functional movement disorder, is characterized by acute or subacute onset of fixed limb, truncal, or facial posturing, incongruent with the action-induced, position-sensitive, and task-specific manifestations of dystonia. We review neurophysiological and neuroimaging data as the basis for a dysfunctional networks in functional dystonia. Reduced intracortical and spinal inhibition contributes to abnormal muscle activation, which may be perpetuated by abnormal sensorimotor processing, impaired selection of movements, and hypoactive sense of agency in the setting of normal movement preparation but abnormal connectivity between the limbic and motor networks. Phenotypic variability may be related to as-yet undefined interactions between abnormal top-down motor regulation and overactivation of areas implicated in self-awareness, self-monitoring, and active motor inhibition such as the cingulate and insular cortices. While there remain many gaps in knowledge, further combined neurophysiological and neuroimaging assessments stand to inform the neurobiological subtypes of functional dystonia and the potential therapeutic applications.
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Affiliation(s)
- Lucia Ricciardi
- Neurosciences Research Centre, Molecular and Clinical Sciences Institute, St George's University of London, London, UK
- Nuffield Department of Clinical Neurosciences, Medical Research Council Brain Network Dynamics Unit, Oxford, UK
| | - Matteo Bologna
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli, IS, Italy
| | - Luca Marsili
- Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
| | - Alberto J Espay
- Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, USA.
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7
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Kaji R. Direct cerebello-striatal loop in dystonia as a possible new target for deep brain stimulation: A revised view of subcortical pathways involved. Front Neurol 2022; 13:912818. [PMID: 36090883 PMCID: PMC9450946 DOI: 10.3389/fneur.2022.912818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
Dystonia is the second most common movement disorder next to tremor, but its pathophysiology remains unsettled. Its therapeutic measures include anti-cholingerics and other medications, in addition to botulinum neurotoxin injections, and stereotaxic surgery including deep brain stimulation (DBS), but there still remain a number of patients resistant to the therapy. Evidence has been accumulating suggesting that basal ganglia in association with the cerebellum are playing a pivotal role in pathogenesis. Clinical observations such as sensory tricks and the effects of muscle afferent stimulation and blockage suggest the conflict between the cortical voluntary motor plan and the subcortical motor program or motor subroutine controlling the intended action semi-automatically. In this review, the current understanding of the possible pathways or loops involved in dystonia is presented, and we review promising new targets for Deep Brain Stimulation (DBS) including the cerebellum.
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Affiliation(s)
- Ryuji Kaji
- Department of Clinical Neuroscience, Tokushima University, Tokushima, Japan
- National Hospital Organization Utano Hospital, Kyoto, Japan
- *Correspondence: Ryuji Kaji
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8
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Interoceptive accuracy and bias in somatic symptom disorder, illness anxiety disorder, and functional syndromes: A systematic review and meta-analysis. PLoS One 2022; 17:e0271717. [PMID: 35980959 PMCID: PMC9387777 DOI: 10.1371/journal.pone.0271717] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 07/06/2022] [Indexed: 12/03/2022] Open
Abstract
Somatic symptom disorder, illness anxiety disorder, and functional syndromes are characterized by burdensome preoccupation with somatic symptoms. Etiological models propose either increased interoceptive accuracy through hypervigilance to the body, or decreased and biased interoception through top-down predictions about sensory events. This systematic review and meta-analysis summarizes findings of 68 studies examining interoceptive accuracy and 8 studies examining response biases in clinical or non-clinical groups. Analyses yielded a medium population effect size for decreased interoceptive accuracy in functional syndromes, but no observable effect in somatic symptom disorder and illness anxiety disorder. The overall effect size was highly heterogeneous. Regarding response bias, there was a small significant effect in somatic symptom disorder and illness anxiety disorder. Our findings strengthen the notion of top-down factors that result in biased rather than accurate perception of body signals in somatic symptom disorder and illness anxiety disorder.
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Aïssa HB, Sala RW, Georgescu Margarint EL, Frontera JL, Varani AP, Menardy F, Pelosi A, Hervé D, Léna C, Popa D. Functional abnormalities in the cerebello-thalamic pathways in a mouse model of DYT25 dystonia. eLife 2022; 11:79135. [PMID: 35699413 PMCID: PMC9197392 DOI: 10.7554/elife.79135] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/27/2022] [Indexed: 11/18/2022] Open
Abstract
Dystonia is often associated with functional alterations in the cerebello-thalamic pathways, which have been proposed to contribute to the disorder by propagating pathological firing patterns to the forebrain. Here, we examined the function of the cerebello-thalamic pathways in a model of DYT25 dystonia. DYT25 (Gnal+/−) mice carry a heterozygous knockout mutation of the Gnal gene, which notably disrupts striatal function, and systemic or striatal administration of oxotremorine to these mice triggers dystonic symptoms. Our results reveal an increased cerebello-thalamic excitability in the presymptomatic state. Following the first dystonic episode, Gnal+/- mice in the asymptomatic state exhibit a further increase of the cerebello-thalamo-cortical excitability, which is maintained after θ-burst stimulations of the cerebellum. When administered in the symptomatic state induced by a cholinergic activation, these stimulations decreased the cerebello-thalamic excitability and reduced dystonic symptoms. In agreement with dystonia being a multiregional circuit disorder, our results suggest that the increased cerebello-thalamic excitability constitutes an early endophenotype, and that the cerebellum is a gateway for corrective therapies via the depression of cerebello-thalamic pathways.
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Affiliation(s)
- Hind Baba Aïssa
- Neurophysiology of Brain Circuits Team, Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Romain W Sala
- Neurophysiology of Brain Circuits Team, Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Elena Laura Georgescu Margarint
- Neurophysiology of Brain Circuits Team, Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Jimena Laura Frontera
- Neurophysiology of Brain Circuits Team, Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Andrés Pablo Varani
- Neurophysiology of Brain Circuits Team, Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Fabien Menardy
- Neurophysiology of Brain Circuits Team, Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Assunta Pelosi
- Inserm UMR-S 1270, Paris, France.,Sorbonne Université, Sciences and Technology Faculty, Paris, France.,Institut du Fer à Moulin, Paris, France
| | - Denis Hervé
- Inserm UMR-S 1270, Paris, France.,Sorbonne Université, Sciences and Technology Faculty, Paris, France.,Institut du Fer à Moulin, Paris, France
| | - Clément Léna
- Neurophysiology of Brain Circuits Team, Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Daniela Popa
- Neurophysiology of Brain Circuits Team, Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris, France
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Nisticò V, Goeta D, Iacono A, Tedesco R, Giordano B, Faggioli R, Priori A, Gambini O, Demartini B. Clinical overlap between functional neurological disorders and autism spectrum disorders: a preliminary study. Neurol Sci 2022; 43:5067-5073. [PMID: 35511383 PMCID: PMC9349073 DOI: 10.1007/s10072-022-06048-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 03/28/2022] [Indexed: 12/03/2022]
Abstract
Functional neurological disorders (FNDs) and autism spectrum disorders (ASDs) share common features in terms of deficits in emotion regulation and recognition, sensory sensitivity, proprioception and interoception. Nevertheless, few studies have assessed their overlap. We recruited 21 patients with FNDs, 30 individuals with ASDs without intellectual disabilities and 45 neurotypical adults (NA). Participants completed: the Autism Quotient (AQ); the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R); and a questionnaire assessing functional neurological symptoms (FNS). ASDs participants also completed the Sensory Perception Quotient-Short Form (SPQ-SF35), assessing sensory sensitivity. In the FNDs sample, no patient scored above the clinical cut-off at the AQ and the 19% scored above the cut-off at the RAADS-R, a prevalence similar to the one we found in NA (15.6%; both p > 0.05). The 86.7% of participants with ASDs reported at least one FNS, a prevalence significantly higher than the NA one (35.6%, p < 0.001). In the ASDs sample, tactile hypersensitivity was found to be a risk factor for functional weakness (OR = 0.74, p = 0.033) and paraesthesia (OR = 0.753, p = 0.019). In conclusions, FNDs individuals did not present autistic traits more than NA, but ASDs individuals presented a higher number of FNSs than NA; this rate was associated with higher sensory sensitivity, especially in the touch domain.
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Affiliation(s)
- Veronica Nisticò
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Presidio San Paolo, via A. di Rudinì, 8, 20142, Milano, Italy.,"Aldo Ravelli" Research Center for Neurotechnology and Experimental Brain Therapeutics, University of Milan, Milan, Italy.,Dipartimento di Psicologia, Università degli Studi di Milano Bicocca, Milan, Italy
| | - Diana Goeta
- U.O. di Psichiatria, Presidio San Carlo, ASST Santi Paolo e Carlo, Milano, Italy
| | - Adriano Iacono
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Presidio San Paolo, via A. di Rudinì, 8, 20142, Milano, Italy
| | - Roberta Tedesco
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Presidio San Paolo, via A. di Rudinì, 8, 20142, Milano, Italy
| | - Barbara Giordano
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Presidio San Paolo, via A. di Rudinì, 8, 20142, Milano, Italy.,U.O. di Psichiatria 52, Presidio San Paolo, ASST Santi Paolo e Carlo, Milano, Italy
| | - Raffaella Faggioli
- U.O. di Psichiatria 52, Presidio San Paolo, ASST Santi Paolo e Carlo, Milano, Italy
| | - Alberto Priori
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Presidio San Paolo, via A. di Rudinì, 8, 20142, Milano, Italy.,"Aldo Ravelli" Research Center for Neurotechnology and Experimental Brain Therapeutics, University of Milan, Milan, Italy.,III Clinica Neurologica, Presidio San Paolo, ASST Santi Paolo e Carlo, Milano, Italy
| | - Orsola Gambini
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Presidio San Paolo, via A. di Rudinì, 8, 20142, Milano, Italy.,"Aldo Ravelli" Research Center for Neurotechnology and Experimental Brain Therapeutics, University of Milan, Milan, Italy.,U.O. di Psichiatria 52, Presidio San Paolo, ASST Santi Paolo e Carlo, Milano, Italy
| | - Benedetta Demartini
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Presidio San Paolo, via A. di Rudinì, 8, 20142, Milano, Italy. .,"Aldo Ravelli" Research Center for Neurotechnology and Experimental Brain Therapeutics, University of Milan, Milan, Italy. .,U.O. di Psichiatria 52, Presidio San Paolo, ASST Santi Paolo e Carlo, Milano, Italy.
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11
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Mark VW. Functional neurological disorder: Extending the diagnosis to other disorders, and proposing an alternate disease term—Attentionally-modifiable disorder. NeuroRehabilitation 2022; 50:179-207. [DOI: 10.3233/nre-228003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: The term “functional neurological disorder,” or “FND,” applies to disorders whose occurrence of neurological symptoms fluctuate with the patient’s attention to them. However, many other disorders that are not called “FND” nonetheless can also follow this pattern. Consequently, guidelines are unclear for diagnosing “FND.” OBJECTIVE: To review the neurological conditions that follow this pattern, but which have not so far been termed “FND,” to understand their overlap with conditions that have been termed “FND,” and to discuss the rationale for why FND has not been diagnosed for them. METHOD: A systematic review of the PubMed literature registry using the terms “fluctuation,” “inconsistency,” or “attention” did not yield much in the way of these candidate disorders. Consequently, this review instead relied on the author’s personal library of peer-reviewed studies of disorders that have resembled FND but which were not termed this way, due to his longstanding interest in this problem. Consequently, this approach was not systematic and was subjective regarding disease inclusion. RESULTS: This review identified numerous, diverse conditions that generally involve fluctuating neurological symptoms that can vary with the person’s attention to them, but which have not been called “FND.” The literature was unclear for reasons for not referring to “FND” in these instances. CONCLUSION: Most likely because of historical biases, the use of the term “FND” has been unnecessarily restricted. Because at its core FND is an attentionally-influenced disorder that can respond well to behavioral treatments, the field of neurological rehabilitation could benefit by extending the range of conditions that could be considered as “FND” and referred for similar behavioral treatments. Because the term “FND” has been viewed unfavorably by some patients and clinical practitioners and whose treatment is not implied, the alternative term attentionally-modifiable disorder is proposed.
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Affiliation(s)
- Victor W. Mark
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
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Korucu ZT, Onurlu İ, Korucu A, Günendi Z. The effect of supervised dynamic exercise program on somatosensory temporal discrimination in patients with fibromyalgia syndrome. Arch Rheumatol 2021; 36:409-418. [PMID: 34870173 PMCID: PMC8612498 DOI: 10.46497/archrheumatol.2021.8412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/22/2020] [Indexed: 11/04/2022] Open
Abstract
Objectives
This study aims to investigate the effect of a supervised dynamic exercise program on somatosensory temporal discrimination (STD) which indicates the central sensory processing ability. Patients and methods
Forty-eight patients (mean age: 43 years; range, 19 to 64 years) with fibromyalgia syndrome (FMS) were included in this prospective, randomized study between April 2018 and October 2018. Demographics and clinical measurements were recorded. The STD threshold was measured by a researcher blinded to the treatment groups. After baseline assessments, the patients were randomized into two groups: the supervised exercise group (SEG) and the home exercise group (HEG) as the control group. The SEG performed submaximal aerobic exercise and low-medium resistant isotonic exercises under the supervision of a physiotherapist, 1-h per day, three days in a week for four weeks. The HEG was given a home-based exercise program consisting of low-to-medium resistance isotonic exercises and aerobic exercises 1-h per day, three days in a week for four weeks. After exercise program, clinical assessments and STD threshold measurement were repeated. Results
Clinical and STD threshold measures improved significantly after four-week exercise program in both groups. The improvements in clinical measures were significantly higher in the SEG. However, there was no difference in the STD threshold improvement between the groups. No correlation was found between the STD threshold measure and clinical features in any patients. Conclusion
Although a significant improvement was achieved in impaired STD threshold with SEG, it was not found to be superior to the amelioration observed with HEG.
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Affiliation(s)
- Zübeyde Tuğçe Korucu
- Department of Physical Medicine and Rehabilitation, Ankara City Hospital, Ankara, Turkey
| | - İlknur Onurlu
- Department of Physical Medicine and Rehabilitation, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Alperen Korucu
- Department of Orthopedics and Traumatology, Ankara City Hospital, Ankara, Turkey
| | - Zafer Günendi
- Department of Physical Medicine and Rehabilitation, Gazi University Faculty of Medicine, Ankara, Turkey
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Smit M, Albanese A, Benson M, Edwards MJ, Graessner H, Hutchinson M, Jech R, Krauss JK, Morgante F, Pérez Dueñas B, Reilly RB, Tinazzi M, Contarino MF, Tijssen MAJ. Dystonia Management: What to Expect From the Future? The Perspectives of Patients and Clinicians Within DystoniaNet Europe. Front Neurol 2021; 12:646841. [PMID: 34149592 PMCID: PMC8211212 DOI: 10.3389/fneur.2021.646841] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 04/19/2021] [Indexed: 01/02/2023] Open
Abstract
Improved care for people with dystonia presents a number of challenges. Major gaps in knowledge exist with regard to how to optimize the diagnostic process, how to leverage discoveries in pathophysiology into biomarkers, and how to develop an evidence base for current and novel treatments. These challenges are made greater by the realization of the wide spectrum of symptoms and difficulties faced by people with dystonia, which go well-beyond motor symptoms. A network of clinicians, scientists, and patients could provide resources to facilitate information exchange at different levels, share mutual experiences, and support each other's innovative projects. In the past, collaborative initiatives have been launched, including the American Dystonia Coalition, the European Cooperation in Science and Technology (COST-which however only existed for a limited time), and the Dutch DystonieNet project. The European Reference Network on Rare Neurological Diseases includes dystonia among other rare conditions affecting the central nervous system in a dedicated stream. Currently, we aim to broaden the scope of these initiatives to a comprehensive European level by further expanding the DystoniaNet network, in close collaboration with the ERN-RND. In line with the ERN-RND, the mission of DystoniaNet Europe is to improve care and quality of life for people with dystonia by, among other endeavors, facilitating access to specialized care, overcoming the disparity in education of medical professionals, and serving as a solid platform to foster international clinical and research collaborations. In this review, both professionals within the dystonia field and patients and caregivers representing Dystonia Europe highlight important unsolved issues and promising new strategies and the role that a European network can play in activating them.
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Affiliation(s)
- Marenka Smit
- Expertise Centre Movement Disorders Groningen, Department of Neurology, University Medical Centre Groningen, Groningen, Netherlands
| | - Alberto Albanese
- Department of Neurology, Istituto di Ricovero e Cura a Carattere Scientifico Humanitas Research Hospital, Milan, Italy
| | | | - Mark J. Edwards
- Neuroscience Research Centre, Institute of Molecular and Clinical Sciences, St George's University of London, London, United Kingdom
| | - Holm Graessner
- Institute of Medical Genetics and Applied Genomics and Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Michael Hutchinson
- Department of Neurology, St. Vincent's University Hospital, Dublin, Ireland
| | - Robert Jech
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University, Prague, Czechia
| | - Joachim K. Krauss
- Department of Neurosurgery, Medizinische Hochschule Hannover, Hanover, Germany
| | - Francesca Morgante
- Neuroscience Research Centre, Institute of Molecular and Clinical Sciences, St George's University of London, London, United Kingdom
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Belen Pérez Dueñas
- Pediatric Neurology Research Group, Hospital Vall d'Hebron–Institut de Recerca (VHIR), Barcelona, Spain
| | - Richard B. Reilly
- School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
| | - Michele Tinazzi
- Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Verona, Italy
| | - Maria Fiorella Contarino
- Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands
- Department of Neurology, Haga Teaching Hospital, The Hague, Netherlands
| | - Marina A. J. Tijssen
- Expertise Centre Movement Disorders Groningen, Department of Neurology, University Medical Centre Groningen, Groningen, Netherlands
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Movement perception of the tonic vibration reflex is abnormal in functional limb weakness. Parkinsonism Relat Disord 2021; 87:1-6. [PMID: 33895678 DOI: 10.1016/j.parkreldis.2021.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/15/2021] [Accepted: 04/10/2021] [Indexed: 01/14/2023]
Abstract
INTRODUCTION We tested the hypothesis that functional limb weakness is associated with possible dysfunction of the central processing of proprioceptive information, by evaluating the amount of tonic vibration reflex (TVR) and the perception of the TVR movement. METHODS The study sample was 20 patients with functional weakness of the lower and/or the upper limbs and 25 healthy controls; delivery of 92-Hz transcutaneous vibration of the biceps brachii tendon of the unrestrained arm stimulated predominantly the muscle spindle afferent and elicited elbow flexion (tonic vibration reflex, TVR). Blindfolded participants had to match the final position of the vibrated arm with their contralateral tracking arm. The TVR and perception of the TVR movement were measured as angle movements of the vibrated arm and the tracking arm, respectively. RESULTS The magnitude of the TVR of the vibrated arm and movement perception of the TVR of the tracking arm were significantly reduced in the patients compared to the controls. No correlation was found between magnitude of the TVR and perception of the TVR movement, suggesting that the abnormalities were independent of each other. Moreover, the abnormalities did not differ between the patients with/without bilateral upper limb involvement or between the affected and the unaffected side in patients with unilateral impairment, suggesting that the observed deficits are independent of motor impairment. CONCLUSIONS Proprioceptive dysfunction may underlie alterations in body movement and in sense of agency in such patients and may play a role in the pathophysiology of functional limb weakness.
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15
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Frucht L, Perez DL, Callahan J, MacLean J, Song PC, Sharma N, Stephen CD. Functional Dystonia: Differentiation From Primary Dystonia and Multidisciplinary Treatments. Front Neurol 2021; 11:605262. [PMID: 33613415 PMCID: PMC7894256 DOI: 10.3389/fneur.2020.605262] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 12/31/2020] [Indexed: 12/12/2022] Open
Abstract
Dystonia is a common movement disorder, involving sustained muscle contractions, often resulting in twisting and repetitive movements and abnormal postures. Dystonia may be primary, as the sole feature (isolated) or in combination with other movement disorders (combined dystonia), or as one feature of another neurological process (secondary dystonia). The current hypothesis is that dystonia is a disorder of distributed brain networks, including the basal ganglia, cerebellum, thalamus and the cortex resulting in abnormal neural motor programs. In comparison, functional dystonia (FD) may resemble other forms of dystonia (OD) but has a different pathophysiology, as a subtype of functional movement disorders (FMD). FD is the second most common FMD and amongst the most diagnostically challenging FMD subtypes. Therefore, distinguishing between FD and OD is important, as the management of these disorders is distinct. There are also different pathophysiological underpinnings in FD, with for example evidence of involvement of the right temporoparietal junction in functional movement disorders that is believed to serve as a general comparator of internal predictions/motor intentions with actual motor events resulting in disturbances in self-agency. In this article, we present a comprehensive review across the spectrum of FD, including oromandibular and vocal forms and discuss the history, clinical clues, evidence for adjunctive "laboratory-based" testing, pathophysiological research and prognosis data. We also provide the approach used at the Massachusetts General Hospital Dystonia Center toward the diagnosis, management and treatment of FD. A multidisciplinary approach, including neurology, psychiatry, physical, occupational therapy and speech therapy, and cognitive behavioral psychotherapy approaches are frequently required; pharmacological approaches, including possible targeted use of botulinum toxin injections and inpatient programs are considerations in some patients. Early diagnosis and treatment may help prevent unnecessary investigations and procedures, while facilitating the appropriate management of these highly complex patients, which may help to mitigate frequently poor clinical outcomes.
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Affiliation(s)
- Lucy Frucht
- Faculty of Arts and Sciences, Harvard University, Boston, MA, United States
| | - David L. Perez
- Cognitive Behavioral Neurology Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Functional Neurological Disorder Research Program, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Neuropsychiatry Division, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Janet Callahan
- MGH Institute of Healthcare Professionals, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Julie MacLean
- Occupational Therapy Department, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Phillip C. Song
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States
| | - Nutan Sharma
- Functional Neurological Disorder Research Program, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Dystonia Center and Movement Disorders Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Christopher D. Stephen
- Functional Neurological Disorder Research Program, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Dystonia Center and Movement Disorders Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
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16
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Tinazzi M, Geroin C, Erro R, Marcuzzo E, Cuoco S, Ceravolo R, Mazzucchi S, Pilotto A, Padovani A, Romito LM, Eleopra R, Zappia M, Nicoletti A, Dallocchio C, Arbasino C, Bono F, Pascarella A, Demartini B, Gambini O, Modugno N, Olivola E, Bonanni L, Antelmi E, Zanolin E, Albanese A, Ferrazzano G, de Micco R, Lopiano L, Calandra-Buonaura G, Petracca M, Esposito M, Pisani A, Manganotti P, Stocchi F, Coletti Moja M, Antonini A, Ercoli T, Morgante F. Functional motor disorders associated with other neurological diseases: Beyond the boundaries of "organic" neurology. Eur J Neurol 2021; 28:1752-1758. [PMID: 33300269 DOI: 10.1111/ene.14674] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND PURPOSE The aims of this study were to describe the clinical manifestations of functional motor disorders (FMDs) coexisting with other neurological diseases ("comorbid FMDs"), and to compare comorbid FMDs with FMDs not overlapping with other neurological diseases ("pure FMDs"). METHODS For this multicenter observational study, we enrolled outpatients with a definite FMD diagnosis attending 25 tertiary movement disorder centers in Italy. Each patient with FMDs underwent a detailed clinical assessment including screening for other associated neurological conditions. Group comparisons (comorbid FMDs vs. pure FMDs) were performed in order to compare demographic and clinical variables. Logistic regression models were created to estimate the adjusted odds ratios (95% confidence intervals) of comorbid FMDs (dependent variable) in relation to sociodemographic and clinical characteristics (independent variables). RESULTS Out of 410 FMDs, 21.7% of patients (n = 89) had comorbid FMDs. The most frequent coexisting neurological diseases were migraine, cerebrovascular disease and parkinsonism. In the majority of cases (86.5%), FMDs appeared after the diagnosis of a neurological disease. Patients with comorbid FMDs were older, and more frequently had tremor, non-neurological comorbidities, paroxysmal non-epileptic seizures, major depressive disorders, and benzodiazepine intake. Multivariate regression analysis showed that diagnosis of comorbid FMDs was more likely associated with longer time lag until the final diagnosis of FMD, presence of tremor and non-neurological comorbidities. CONCLUSIONS Our findings highlight the need for prompt diagnosis of FMDs, given the relatively high frequency of associated neurological and non-neurological diseases.
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Affiliation(s)
- Michele Tinazzi
- Neurology Unit, Movement Disorders Division, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Christian Geroin
- Neurology Unit, Movement Disorders Division, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Roberto Erro
- Department of Medicine, Surgery and Dentistry -Scuola Medica Salernitana, Center for Neurodegenerative Diseases (CEMAND), University of Salerno, Baronissi, SA, Italy
| | - Enrico Marcuzzo
- Neurology Unit, Movement Disorders Division, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Sofia Cuoco
- Department of Medicine, Surgery and Dentistry -Scuola Medica Salernitana, Center for Neurodegenerative Diseases (CEMAND), University of Salerno, Baronissi, SA, Italy
| | - Roberto Ceravolo
- Neurology Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Sonia Mazzucchi
- Neurology Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Andrea Pilotto
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,FERB Onlus, Ospedale S. Isidoro, Trescore Balneario, Bergamo, Italy
| | - Alessandro Padovani
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Luigi Michele Romito
- Parkinson and Movement Disorders Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Roberto Eleopra
- Parkinson and Movement Disorders Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Mario Zappia
- Section of Neurosciences, Department G.F. Ingrassia, University of Catania, Catania, Italy
| | - Alessandra Nicoletti
- Section of Neurosciences, Department G.F. Ingrassia, University of Catania, Catania, Italy
| | - Carlo Dallocchio
- Neurology Unit, Department of Medical Area, ASST Pavia, Pavia, Italy
| | - Carla Arbasino
- Neurology Unit, Department of Medical Area, ASST Pavia, Pavia, Italy
| | - Francesco Bono
- Botulinum Toxin Center, Neurology Unit, A.O.U. Mater Domini, Catanzaro, Italy
| | - Angelo Pascarella
- Botulinum Toxin Center, Neurology Unit, A.O.U. Mater Domini, Catanzaro, Italy
| | - Benedetta Demartini
- Aldo Ravelli Research Center for Neurotechnology and Experimental Brain Therapeutics - Department of Health Sciences, University of Milan, Milan, Italy
| | - Orsola Gambini
- Aldo Ravelli Research Center for Neurotechnology and Experimental Brain Therapeutics - Department of Health Sciences, University of Milan, Milan, Italy
| | | | | | - Laura Bonanni
- Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio, Chieti-Pescara, Italy
| | - Elena Antelmi
- Neurology Unit, Movement Disorders Division, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Elisabetta Zanolin
- Unit of Epidemiology and Medical Statistics, Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Alberto Albanese
- Department of Neurology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Gina Ferrazzano
- Department of Human Neurosciences, Università La Sapienza, Rome, Italy
| | - Rosa de Micco
- Department of Advanced Medical and Surgery Sciences, University of Campania - Luigi Vanvitelli, Naples, Italy
| | - Leonardo Lopiano
- Department of Neuroscience - Rita Levi Montalcini, University of Turin, Turin, Italy
| | - Giovanna Calandra-Buonaura
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,Institute of Neurological Sciences of Bologna, IRCCS, Bologna, Italy
| | - Martina Petracca
- Movement Disorder Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | | | | | - Paolo Manganotti
- Clinical Neurology Unit, Department of Medical, Surgical and Health Services, University of Trieste, Trieste, Italy
| | - Fabrizio Stocchi
- University and Institute of Research and Medical Care San Raffaele, Roma, Italy
| | | | - Angelo Antonini
- Movement Disorders Unit, Department of Neuroscience, University of Padua, Padua, Italy
| | - Tommaso Ercoli
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Francesca Morgante
- Neurosciences Research Centre, Molecular and Clinical Sciences Neurosciences Research Centre, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK.,Department of Experimental and Clinical Medicine, University of Messina, Messina, Italy
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Functional and Idiopathic Cervical Dystonia in Two Family Members: A Challenging Diagnosis. Tremor Other Hyperkinet Mov (N Y) 2020; 10:51. [PMID: 33354397 PMCID: PMC7731715 DOI: 10.5334/tohm.558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Background: Cervical dystonia (CD) often occurs in the same family. Case report: A 40-year-old woman presented with a longstanding history of CD and signs of inconsistency at history taking and neurological examination; her 65-year-old mother was diagnosed instead with idiopathic CD, which had begun 7 years after the onset of CD in her daughter. Discussion: Idiopathic and functional CD share common clinical and endophenotypic traits, making the differential diagnosis particularly challenging. A complete examination is warranted.
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Thomsen BLC, Teodoro T, Edwards MJ. Biomarkers in functional movement disorders: a systematic review. J Neurol Neurosurg Psychiatry 2020; 91:1261-1269. [PMID: 33087421 DOI: 10.1136/jnnp-2020-323141] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/11/2020] [Accepted: 09/23/2020] [Indexed: 11/04/2022]
Abstract
Functional movement disorders (FMD) are proposed to reflect a specific problem with voluntary control of movement, despite normal intent to move and an intact neural capacity for movement. In many cases, a positive diagnosis of FMD can be established on clinical grounds. However, the diagnosis remains challenging in certain scenarios, and there is a need for predictors of treatment response and long-term prognosis.In this context, we performed a systematic review of biomarkers in FMD. Eighty-six studies met our predefined criteria and were included.We found fairly reliable electroencephalography and electromyography-based diagnostic biomarkers for functional myoclonus and tremor. Promising biomarkers have also been described for functional paresis, gait and balance disorders. In contrast, there is still a lack of diagnostic biomarkers of functional dystonia and tics, where clinical diagnosis is often also more challenging. Importantly, many promising findings focus on pathophysiology and reflect group-level comparisons, but cannot differentiate on an individual basis. Some biomarkers also require access to time-consuming and resource-consuming techniques such as functional MRI.In conclusion, there are important gaps in diagnostic biomarkers in FMD in the areas of most clinical uncertainty. There is also is a lack of treatment response and prognostic biomarkers to aid in the selection of patients who would benefit from rehabilitation and other forms of treatment.
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Affiliation(s)
- Birgitte Liang Chen Thomsen
- Neurology, Bispebjerg Hospital, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tiago Teodoro
- Neurosciences Research Centre, St George's University of London, London, UK.,Instituto de Medicina Molecular, University of Lisbon, Lisboa, Portugal
| | - Mark J Edwards
- Neurosciences Research Centre, St George's University of London, London, UK
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19
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Neurophysiological insights in dystonia and its response to deep brain stimulation treatment. Exp Brain Res 2020; 238:1645-1657. [PMID: 32638036 PMCID: PMC7413898 DOI: 10.1007/s00221-020-05833-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 05/11/2020] [Indexed: 01/29/2023]
Abstract
Dystonia is a movement disorder characterised by involuntary muscle contractions resulting in abnormal movements, postures and tremor. The pathophysiology of dystonia is not fully understood but loss of neuronal inhibition, excessive sensorimotor plasticity and defective sensory processing are thought to contribute to network dysfunction underlying the disorder. Neurophysiology studies have been important in furthering our understanding of dystonia and have provided insights into the mechanism of effective dystonia treatment with pallidal deep brain stimulation. In this article we review neurophysiology studies in dystonia and its treatment with Deep Brain Stimulation, including Transcranial magnetic stimulation studies, studies of reflexes and sensory processing, and oscillatory activity recordings including local field potentials, micro-recordings, EEG and evoked potentials.
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20
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Sadnicka A, Daum C, Meppelink AM, Manohar S, Edwards M. Reduced drift rate: a biomarker of impaired information processing in functional movement disorders. Brain 2020; 143:674-683. [PMID: 31865371 DOI: 10.1093/brain/awz387] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 10/15/2019] [Accepted: 10/17/2019] [Indexed: 12/21/2022] Open
Abstract
Functional neurological disorder is a common and phenomenologically diverse condition. Resultant disability is caused by both the dominant clinical presentation, e.g. paralysis or tremor and additional symptomatology such as cognitive symptoms. Recently the similarity of neuropsychiatric profiles across a range of functional syndromes has been highlighted. This is suggestive of a common underlying mechanism with a theoretical deficit of information processing proposed. Identification of an experimental biomarker for such deficits could offer novel assessment and therapeutic strategies. In this study, we took the temporal discrimination threshold as a paradigm that can be used to model sensory processing in functional movement disorders. Our hypothesis was that we would be able to delineate markers of slowed information processing in this paradigm removed from the phenomenological presentation with a movement disorder. We recorded both response accuracy and reaction time in a two-choice temporal resolution/discrimination task in 36 patients with functional movement disorders and 36 control subjects. A psychometric function was fitted to accuracy data for each individual revealing both abnormally high threshold values (P = 0.0053) and shallow psychometric slopes in patients (P = 0.0015). Patients with functional movement disorders also had significantly slower response times (P = 0.0065). We then used a well-established model for decision-making (the drift diffusion model) that uses both response accuracy and reaction time data to estimate mechanistic physiological dimensions of decision-making and sensory processing. This revealed pathologically reduced drift rate in the patient group, a parameter that quantifies the quality and rate of information accumulation within this sensory task (P = 0.002). We discuss how the deficits we observed in patients with functional movement disorders are likely to stem from abnormal allocation of attention that impairs the quality of sensory information available. Within a predictive coding framework sensory information could be down-weighted in favour of predictions encoded by the prior. Our results therefore offer a parsimonious account for a range of experimental and clinical findings. Reduced drift rate is a potential experimental marker for a generalized deficit in information processing across functional disorders that allows diverse symptomatology to be quantified under a common disease framework.
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Affiliation(s)
- 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
| | - Corinna Daum
- Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Department of Neurology, Zug Cantonal Hospital, Baar, Switzerland
| | - Anne-Marthe Meppelink
- Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,SEIN - Stichting Epilepsie Instellingen Nederland, Zwolle, The Netherlands
| | - Sanjay Manohar
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Mark Edwards
- Motor Control and Movement Disorders Group, St George's University of London, London, UK
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21
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Matthews J, Nagao K, Ding C, Newby R, Kempster P, Hohwy J. Raised visual contrast thresholds with intact attention and metacognition in functional motor disorder. Cortex 2020; 125:161-174. [PMID: 31991241 DOI: 10.1016/j.cortex.2019.12.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 08/04/2019] [Accepted: 12/09/2019] [Indexed: 02/07/2023]
Abstract
Functional motor disorders (FMDs) are distinguished by signs that lack congruence with recognised patterns of organic disease and show inconsistency over time. Their pathophysiology is poorly understood, but there is evidence that irregularities in perceptual and cognitive processing lie at the heart of these conditions. Here, we draw on a predictive coding account of functional neurological disorders to study perceptual decision-making in three groups: 20 patients with FMDs (14 with functional movements and 6 with functional weakness), 20 with phenotypically-matched organic motor disorders, and 20 age-matched healthy controls. We examine four cognitive domains with putative roles in FMD pathogenesis: attention, expectations, sensory processing (perceptual sensitivity), and metacognition (introspective evaluation of performance). We augmented a dual-task paradigm, manipulating the visual contrast required for target detection to examine these domains in one design. With sensory input (stimulus contrast) psychometrically adjusted to staircase target detection at a fixed level for all groups, the FMD group exhibited statistically equivalent attentional, expectational and metacognitive processing to healthy controls. However, we demonstrate Bayesian evidence and a frequentist trend that FMD patients require higher visual contrast than controls to maintain the same detection sensitivity (BF10 = 8.1, pholm = .066). This was statistically equivalent to the visual contrast required by the organic group, and unlikely to be accounted for by medication use or comorbid psychopathology. The organic group showed differences in processing of attention and expectations for target detection that were not observed in either healthy controls or the functional group. The distinctive behavioural profile of FMDs may arise from abnormalities in basic sensory processing, while higher attentional, expectational and metacognitive mechanisms remain intact. Conceptualising functional neurological disorders under a predictive coding account may consolidate and refine existing pathophysiological theories about them.
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Affiliation(s)
- Julian Matthews
- Cognition & Philosophy Lab, Monash University, Clayton, Australia.
| | - Kanae Nagao
- Neurosciences Department, Monash Medical Centre, Clayton, Australia.
| | - Catherine Ding
- Neurosciences Department, Monash Medical Centre, Clayton, Australia.
| | - Rachel Newby
- Neurosciences Department, Monash Medical Centre, Clayton, Australia.
| | - Peter Kempster
- Neurosciences Department, Monash Medical Centre, Clayton, Australia; Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Australia.
| | - Jakob Hohwy
- Cognition & Philosophy Lab, Monash University, Clayton, Australia.
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Vreeswijk SME, Hoang TNL, Korzeczek A, Neef NE, Wolff von Gudenberg A, Paulus W, Sommer M. No Evidence for Dystonia-Like Sensory Overflow of Tongue Representations in Adults Who Stutter. Front Hum Neurosci 2019; 13:336. [PMID: 31636553 PMCID: PMC6787140 DOI: 10.3389/fnhum.2019.00336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/12/2019] [Indexed: 11/13/2022] Open
Abstract
Persistent developmental stuttering (PDS) disrupts speech fluency in about 1% of adults. Although many models of speech production assume an intact sensory feedback from the speech organs to the brain, very little is actually known about the integrity of their sensory representation in PDS. Here, we studied somatosensory evoked potentials (SEPs) in adults who stutter (AWS), with the aim of probing the integrity of sensory pathways. In addition, we tested the processing of dual sensory input to address a putative link between stuttering and focal dystonia. In 15 AWS (aged 15-55 years; three females) and 14 matched fluent speaking adults (ANS), we recorded SEPs at C5' and C6' induced by stimulating separately or simultaneously the tongue or the cheek at the corner of the mouth. We determined latencies (N13, P19, and N27) and peak-to-peak amplitudes (N13-P19, P19-N27). We divided amplitudes from simultaneous stimulation by the sum of those from separate stimulation. Amplitude ratios did not differ between groups, indicating normal processing of dual sensory input. This does not support a clinical analogy between focal dystonia and persistent stuttering. SEP latencies as a measure of transmission speed in sensory pathways were significantly shorter in stuttering subjects than in fluent speaking participants, however, this might have been related to a trend for a height difference between groups, and was not confirmed in a replication dataset. In summary, we did not find evidence for dystonia-like sensory overflow of tongue representations in AWS.
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Affiliation(s)
- Sarah M E Vreeswijk
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg-August-University, Göttingen, Germany
| | - T N Linh Hoang
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg-August-University, Göttingen, Germany
| | - Alexandra Korzeczek
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg-August-University, Göttingen, Germany
| | - Nicole E Neef
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | | | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg-August-University, Göttingen, Germany
| | - Martin Sommer
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg-August-University, Göttingen, Germany
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Conte A, Rocchi L, Latorre A, Belvisi D, Rothwell JC, Berardelli A. Ten‐Year Reflections on the Neurophysiological Abnormalities of Focal Dystonias in Humans. Mov Disord 2019; 34:1616-1628. [DOI: 10.1002/mds.27859] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/20/2019] [Accepted: 08/23/2019] [Indexed: 12/12/2022] Open
Affiliation(s)
- Antonella Conte
- Department of Human Neurosciences Sapienza, University of Rome Rome Italy
- IRCCS Neuromed Pozzilli (IS) Italy
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences UCL Queen Square Institute of Neurology London UK
| | - Anna Latorre
- Department of Human Neurosciences Sapienza, University of Rome Rome Italy
- 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
| | - Alfredo Berardelli
- Department of Human Neurosciences Sapienza, University of Rome Rome Italy
- IRCCS Neuromed Pozzilli (IS) Italy
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Vizcarra JA, Lopez-Castellanos JR, Dwivedi AK, Schmerler DA, Ries S, Espay AJ. OnabotulinumtoxinA and cognitive behavioral therapy in functional dystonia: A pilot randomized clinical trial. Parkinsonism Relat Disord 2019; 63:174-178. [DOI: 10.1016/j.parkreldis.2019.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/17/2019] [Accepted: 02/11/2019] [Indexed: 11/25/2022]
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Baizabal-Carvallo JF, Hallett M, Jankovic J. Pathogenesis and pathophysiology of functional (psychogenic) movement disorders. Neurobiol Dis 2019; 127:32-44. [PMID: 30798005 DOI: 10.1016/j.nbd.2019.02.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/31/2019] [Accepted: 02/20/2019] [Indexed: 11/17/2022] Open
Abstract
Functional movement disorders (FMDs), known over time as "hysteria", "dissociative", "conversion", "somatoform", "non-organic" and "psychogenic" disorders, are characterized by having a voluntary quality, being modifiable by attention and distraction but perceived by the patient as involuntary. Although a high prevalence of depression and anxiety is observed in these patients, a definitive role of psychiatric disorders in FMDs has not been proven, and many patients do not endorse such manifestations. Stressful events, social influences and minor trauma may precede the onset of FMDs, but their pathogenic mechanisms are unclear. Patients with FMDs have several abnormalities in their neurobiology including strengthened connectivity between the limbic and motor networks. Additionally, there is altered top-down regulation of motor activities and increased activation of areas implicated in self-awareness, self-monitoring, and active motor inhibition such as the cingulate and insular cortex. Decreased activation of the supplementary motor area (SMA) and pre-SMA, implicated in motor control and preparation, is another finding. The sense of agency defined as the feeling of controlling external events through one's own action also seems to be impaired in individuals with FMDs. Correlating with this is a loss of intentional binding, a subjective time compression between intentional action and its sensory consequences. Organic and functional dystonia may be difficult to differentiate since they share diverse neurophysiological features including decreased cortical inhibition, and similar local field potentials in the globus pallidus and thalamus; although increased cortical plasticity is observed only in patients with organic dystonia. Advances in the pathogenesis and pathophysiology of FMDs may be helpful to understand the nature of these disorders and plan further treatment strategies.
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Affiliation(s)
- José Fidel Baizabal-Carvallo
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA; University of Guanajuato, Mexico.
| | - Mark Hallett
- Human Motor Control Section, NINDS, National Institutes of Health, Bethesda, MD, USA
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA
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26
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Gunendi Z, Polat M, Vuralli D, Cengiz B. Somatosensory temporal discrimination is impaired in fibromyalgia. J Clin Neurosci 2018; 60:44-48. [PMID: 30528354 DOI: 10.1016/j.jocn.2018.10.067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/15/2018] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Fibromyalgia is the prototypical central sensitivity syndrome which is associated with increased sensitivity to pain and other stimuli. In this study, we aimed to evaluate whether somatosensory temporal discrimination ability, which provides information about central processing of sensory stimuli, was impaired in patients with fibromyalgia. METHODS Fifteen patients with fibromyalgia and 15 healthy subjects participated in the study. Demographic characteristics of participants and severity for fatigue, sleep quality, cognitive symptoms, somatic symptoms and health-related quality of life in fibromyalgia patients were recorded. Somatosensory temporal discrimination thresholds were measured from the dorsum of the dominant hands of the participants by using a constant current stimulator (Medtronic, Keypoint). RESULTS Patients with fibromyalgia had higher somatosensory temporal discrimination thresholds than healthy subjects (p < 0.001). There were significant correlations between STDTs and pain intensity, FIQ scores and symptom severity scale scores in fibromyalgia group (p = 0.006, r = 0.68; p = 0.037, r = 0.54; p = 0.017, r = 0.61 respectively). CONCLUSION Somatosensory temporal discrimination ability is impaired in fibromyalgia patients compared to healthy subjects. Disrupted somatosensory temporal discrimination ability correlates with increased widespread pain and severity of other symptoms including fatigue, sleep quality, cognitive symptoms, somatic symptoms and decreased functional status. The impaired somatosensory temporal discrimination ability indicates an alteration in higher cognitive sensory processing in fibromyalgia patients.
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Affiliation(s)
- Zafer Gunendi
- Gazi University Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Besevler, 06510 Ankara, Turkey
| | - Musa Polat
- Gazi University Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Besevler, 06510 Ankara, Turkey
| | - Doga Vuralli
- Gazi University, Faculty of Medicine, Department of Neurology and Algology, Besevler, 06510 Ankara, Turkey.
| | - Bulent Cengiz
- Gazi University, Faculty of Medicine, Department of Neurology, Motor Control Laboratory, Besevler, 06510 Ankara, Turkey
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Spatial Integration of Somatosensory Inputs during Sensory-Motor Plasticity Phenomena Is Normal in Focal Hand Dystonia. Neural Plast 2018; 2018:4135708. [PMID: 30405710 PMCID: PMC6199881 DOI: 10.1155/2018/4135708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 07/18/2018] [Accepted: 08/29/2018] [Indexed: 11/28/2022] Open
Abstract
Background Surround inhibition is a system that sharpens sensation by creating an inhibitory zone around the central core of activation. In the motor system, this mechanism probably contributes to the selection of voluntary movements, and it seems to be lost in dystonia. Objectives. To explore if sensory information is abnormally processed and integrated in focal hand dystonia (FHD) and if surround inhibition phenomena are operating during sensory-motor plasticity and somatosensory integration in normal humans and in patients with FHD. Methods. We looked at the MEP facilitation obtained after 5 Hz repetitive paired associative stimulation of median (PAS M), ulnar (PAS U), and median + ulnar nerve (PAS MU) stimulation in 8 normal subjects and 8 FHD. We evaluated the ratio MU/(M + U) ∗ 100 and the spatial and temporal somatosensory integration recording the somatosensory evoked potentials (SEPs) evoked by a dual nerve input. Results FHD had two main abnormalities: first, the amount of facilitation was larger than normal subjects; second, the spatial specificity was lost. The MU/(M + U) ∗ 100 ratio was similar in healthy subjects and in FHD patients, and the somatosensory integration was normal in this subset of patients. Conclusions. The inhibitory integration of somatosensory inputs and the somatosensory inhibition are normal in patients with focal dystonia as well as lateral surrounding inhibition phenomena during sensory-motor plasticity in FHD.
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28
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Fiorio M, Emadi Andani M, Recchia S, Tinazzi M. The somatosensory temporal discrimination threshold changes after a placebo procedure. Exp Brain Res 2018; 236:2983-2990. [DOI: 10.1007/s00221-018-5357-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/10/2018] [Indexed: 10/28/2022]
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Abstract
Within the field of movement disorders, the conceptual understanding of dystonia has continued to evolve. Clinical advances have included improvements in recognition of certain features of dystonia, such as tremor, and understanding of phenotypic spectrums in the genetic dystonias and dystonia terminology and classification. Progress has also been made in the understanding of underlying biological processes which characterize dystonia from discoveries using approaches such as neurophysiology, functional imaging, genetics, and animal models. Important advances include the role of the cerebellum in dystonia, the concept of dystonia as an aberrant brain network disorder, additional evidence supporting the concept of dystonia endophenotypes, and new insights into psychogenic dystonia. These discoveries have begun to shape treatment approaches as, in parallel, important new treatment modalities, including magnetic resonance imaging-guided focused ultrasound, have emerged and existing interventions such as deep brain stimulation have been further refined. In this review, these topics are explored and discussed.
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Affiliation(s)
- Stephen Tisch
- Faculty of Medicine, University of New South Wales, Sydney, Australia.,Department of Neurology, St Vincent's Hospital, Sydney, Australia
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30
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Morgante F, Matinella A, Andrenelli E, Ricciardi L, Allegra C, Terranova C, Girlanda P, Tinazzi M. Pain processing in functional and idiopathic dystonia: An exploratory study. Mov Disord 2018; 33:1340-1348. [PMID: 29737565 DOI: 10.1002/mds.27402] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 02/27/2018] [Accepted: 03/05/2018] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Pain is often experienced by patients with functional dystonia and idiopathic cervical dystonia and is likely to be determined by different neural mechanisms. OBJECTIVE In this exploratory study, we tested the sensory-discriminative and cognitive-emotional component of pain in patients with functional and idiopathic dystonia. METHODS Ten patients with idiopathic cervical dystonia, 12 patients with functional dystonia, and 16 age- and sex-matched healthy controls underwent psychophysical testing of tactile and pain thresholds and pain tolerance. We delivered electrical pulses of increasing intensity to the index finger of each hand and the halluces of each foot. Pain threshold and pain tolerance were respectively defined as the (1) intensity at which sensation changed from unpainful to faintly painful and (2) intensity at which painful sensation was intolerable. RESULTS No differences were found between the three groups for tactile and pain thresholds assessed in hands and feet. Pain tolerance was significantly increased in all body regions only in functional dystonia. Patients with continuous functional dystonia had higher pain tolerance compared to subjects with paroxysmal functional dystonia and idiopathic cervical dystonia. There was no correlation between pain tolerance and pain scores, depression, anxiety, disease duration, and motor disability in both groups. CONCLUSIONS Patients with functional dystonia have a dissociation between the sensory-discriminative and cognitive-emotional components of pain, as revealed by normal pain thresholds and increased pain tolerance. Abnormal connectivity between the motor and limbic systems might account for abnormal pain processing in functional dystonia. © 2018 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Francesca Morgante
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.,Neurosciences Research Centre, Molecular and Clinical Sciences Research Institute, St George's University of London, London, United Kingdom
| | - Angela Matinella
- Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Elisa Andrenelli
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy
| | - Lucia Ricciardi
- Neurosciences Research Centre, Molecular and Clinical Sciences Research Institute, St George's University of London, London, United Kingdom
| | - Cosimo Allegra
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Carmen Terranova
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Paolo Girlanda
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Michele Tinazzi
- Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona, Italy
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31
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Chen R. Spatial versus temporal inhibition in dystonia. Clin Neurophysiol 2018; 129:458-459. [PMID: 29305207 DOI: 10.1016/j.clinph.2017.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 12/14/2017] [Indexed: 10/18/2022]
Affiliation(s)
- Robert Chen
- Division of Neurology, Department of Medicine, University of Toronto and Krembil Research Institute, University Health Network, 7McL409, 399 Bathurst St, Toronto, Ontario M5T 2S8, Canada.
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32
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Pastore A, Pierri G, Fabio G, Ferramosca S, Gigante A, Superbo M, Pellicciari R, Margari F. Differences in psychopathology and behavioral characteristics of patients affected by conversion motor disorder and organic dystonia. Neuropsychiatr Dis Treat 2018; 14:1287-1295. [PMID: 29849460 PMCID: PMC5965383 DOI: 10.2147/ndt.s151695] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Typically, the diagnosis of conversion motor disorder (CMD) is achieved by the exclusion of a wide range of organic illnesses rather than by applying positive criteria. New diagnostic criteria are highly needed in this scenario. The main aim of this study was to explore the use of behavioral features as an inclusion criterion for CMD, taking into account the relationship of the patients with physicians, and comparing the results with those from patients affected by organic dystonia (OD). PATIENTS AND METHODS Patients from the outpatient Movement Disorder Service were assigned to either the CMD or the OD group based on Fahn and Williams criteria. Differences in sociodemographics, disease history, psychopathology, and degree of satisfaction about care received were assessed. Patient-neurologist agreement about the etiological nature of the disorder was also assessed using the k-statistic. A logistic regression analysis estimated the discordance status as a predictor to case/control status. RESULTS In this study, 31 CMD and 31 OD patients were included. CMD patients showed a longer illness life span, involvement of more body regions, higher comorbidity with anxiety, depression, and borderline personality disorder, as well as higher negative opinions about physicians' delivering of proper care. Contrary to our expectations, CMD disagreement with neurologists about the etiological nature of the disorder was not statistically significant. Additional analysis showed that having at least one personality disorder was statistically associated with the discordance status. CONCLUSION This study suggests that CMD patients show higher conflicting behavior toward physicians. Contrary to our expectations, they show awareness of their psychological needs, suggesting a possible lack of recognition of psychological distress in the neurological setting.
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Affiliation(s)
- Adriana Pastore
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Grazia Pierri
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Giada Fabio
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Silvia Ferramosca
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Angelo Gigante
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Maria Superbo
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Roberta Pellicciari
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Francesco Margari
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
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Sadnicka A, Daum C, Cordivari C, Bhatia KP, Rothwell JC, Manohar S, Edwards MJ. Mind the gap: temporal discrimination and dystonia. Eur J Neurol 2017; 24:796-806. [PMID: 28544409 DOI: 10.1111/ene.13293] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 03/06/2017] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE One of the most widely studied perceptual measures of sensory dysfunction in dystonia is the temporal discrimination threshold (TDT) (the shortest interval at which subjects can perceive that there are two stimuli rather than one). However the elevated thresholds described may be due to a number of potential mechanisms as current paradigms test not only temporal discrimination but also extraneous sensory and decision-making parameters. In this study two paradigms designed to better quantify temporal processing are presented and a decision-making model is used to assess the influence of decision strategy. METHODS 22 patients with cervical dystonia and 22 age-matched controls completed two tasks (i) temporal resolution (a randomized, automated version of existing TDT paradigms) and (ii) interval discrimination (rating the length of two consecutive intervals). RESULTS In the temporal resolution task patients had delayed (P = 0.021) and more variable (P = 0.013) response times but equivalent discrimination thresholds. Modelling these effects suggested this was due to an increased perceptual decision boundary in dystonia with patients requiring greater evidence before committing to decisions (P = 0.020). Patient performance on the interval discrimination task was normal. CONCLUSIONS Our work suggests that previously observed abnormalities in TDT may not be due to a selective sensory deficit of temporal processing as decision-making itself is abnormal in cervical dystonia.
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Affiliation(s)
- A Sadnicka
- Sobell Department for Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - C Daum
- Sobell Department for Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - C Cordivari
- Sobell Department for Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - K P Bhatia
- Sobell Department for Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - J C Rothwell
- Sobell Department for Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - S Manohar
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - M J Edwards
- Institute of Cardiovascular and Cell Sciences, St George's University, London, UK
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34
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Temporal discrimination threshold with healthy aging. Neurobiol Aging 2016; 43:174-9. [PMID: 27255827 DOI: 10.1016/j.neurobiolaging.2016.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 02/10/2016] [Accepted: 04/13/2016] [Indexed: 01/16/2023]
Abstract
The temporal discrimination threshold (TDT) is the shortest interstimulus interval at which a subject can perceive successive stimuli as separate. To investigate the effects of aging on TDT, we studied tactile TDT using the method of limits with 120% of sensory threshold in each hand for each of 100 healthy volunteers, equally divided among men and women, across 10 age groups, from 18 to 79 years. Linear regression analysis showed that age was significantly related to left-hand mean, right-hand mean, and mean of 2 hands with R-square equal to 0.08, 0.164, and 0.132, respectively. Reliability analysis indicated that the 3 measures had fair-to-good reliability (intraclass correlation coefficient: 0.4-0.8). We conclude that TDT is affected by age and has fair-to-good reproducibility using our technique.
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Abstract
Functional neurologic disorders are largely genuine and represent conversion disorders, where the dysfunction is unconscious, but there are some that are factitious, where the abnormality is feigned and conscious. Malingering, which can have the same manifestations, is similarly feigned, but not considered a genuine disease. There are no good methods for differentiating these three entities at the present time. Physiologic studies of functional weakness and sensory loss reveal normal functioning of primary motor and sensory cortex, but abnormalities of premotor cortex and association cortices. This suggests a top-down influence creating the dysfunction. Studies of functional tremor and myoclonus show that these disorders utilize normal voluntary motor structures to produce the involuntary movements, again suggesting a higher-level abnormality. Agency is abnormal and studies shows that dysfunction of the temporoparietal junction may be a correlate. The limbic system is overactive and might initiate involuntary movements, but the mechanism for this is not known. The limbic system would then be the source of top-down dysfunction. It can be speculated that the involuntary movements are involuntary due to lack of proper feedforward signaling.
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Affiliation(s)
- M Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
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36
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Abstract
Although currently lacking a sensitive and specific electrophysiologic battery test, functional (psychogenic) dystonia can sometimes be diagnosed with clinically definite certainty using available criteria. Certain regional phenotypes have been recognized as distinctive, such as unilateral lip and jaw deviation, laterocollis with ipsilateral shoulder elevation and contralateral shoulder depression, fixed wrist and finger flexion with relative sparing of the thumb and index fingers, and fixed foot plantar flexion and inversion. The pathophysiologic abnormalities in functional dystonia overlap substantially with those of organic dystonia, with similar impairments in cortical and spinal inhibition and somatosensory processing, but with emerging data suggesting abnormalities in regional blood flow and activation patterns on positron emission tomography and functional magnetic resonance imaging, respectively. Management of functional dystonia begins with compassionate and assertive debriefing of the diagnosis to ensure full acceptance by the patient, a critical step in enhancing the likelihood of success with physical rehabilitation, and psychodynamic or cognitive therapy. Physical therapy, with or without cognitive behavioral therapy, appears to be of benefit but has not yet been examined in a controlled fashion. While the prognosis remains grim for a substantial majority of patients, partly stemming from restricted mobility, delayed diagnosis, and inappropriate pharmacotherapy, early recognition and initiation of therapy stand to minimize iatrogenic harm and unnecessary laboratory investigations, and potentially reduce the long-term neurologic disability.
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Ferrazzano G, Conte A, Fabbrini G, Bologna M, Macerollo A, Defazio G, Hallett M, Berardelli A. Botulinum toxin and blink rate in patients with blepharospasm and increased blinking. J Neurol Neurosurg Psychiatry 2015; 86:336-40. [PMID: 24963123 DOI: 10.1136/jnnp-2014-307821] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE The aim of the study was to investigate the effect of botulinum toxin (BoNT) on blink rate (BR) in patients with blepharospasm (BSP) and increased blinking (IB). METHODS 37 patients with a clinical diagnosis of primary BSP (19 patients had tonic orbicularis oculi (OO) spasms and 18 patients had clonic OO spasms) and 8 patients with IB were included in this case-control study. All subjects underwent a standardised video protocol and clinical evaluation with a validated questionnaire designed to identify eye symptoms and Blepharospasm Disability Index (BSDI) before and 1 month after BoNT injection. BR was measured from the video recording before and after BoNT. BR in BSP and IB patients was compared with that from a group of healthy subjects and from a group of patients with hemifacial spasm (HFS). BR in HFS was also measured before and after BoNT. RESULTS BR was increased in patients with IB and in BSP patients with clonic spasms but not in BSP patients with tonic spasms. BoNT reduced BR in patients with IB and in patients with clonic spasms, but not in patients with tonic spasms. BoNT left BR in patients with HFS unchanged. Changes in BR after BoNT were also independent of the presence of ocular symptoms. Despite the differential response of BR, BoNT significantly reduced BSDI in patients with BSP and IB. CONCLUSIONS BoNT differentially modulates BR in patients with BSP and IB depending on the baseline BR. BoNT injection reduces BR only when the blink generator is overactive, possibly influencing tear film retention.
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Affiliation(s)
- Gina Ferrazzano
- Department of Neurology and Psychiatry, 'Sapienza' University of Rome, Rome, Italy
| | - Antonella Conte
- Department of Neurology and Psychiatry, 'Sapienza' University of Rome, Rome, Italy IRCCS Neuromed Institute, Pozzilli (IS), Italy
| | - Giovanni Fabbrini
- Department of Neurology and Psychiatry, 'Sapienza' University of Rome, Rome, Italy IRCCS Neuromed Institute, Pozzilli (IS), Italy
| | | | - Antonella Macerollo
- Department of Neurosciences and Sensory Organs, 'Aldo Moro' University of Bari, Bari, Italy
| | - Giovanni Defazio
- Department of Neurosciences and Sensory Organs, 'Aldo Moro' University of Bari, Bari, Italy
| | - Mark Hallett
- Human Motor Control Section, NINDS, NIH, Bethesda, Maryland, USA
| | - Alfredo Berardelli
- Department of Neurology and Psychiatry, 'Sapienza' University of Rome, Rome, Italy IRCCS Neuromed Institute, Pozzilli (IS), Italy
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Tinazzi M, Fasano A, Peretti A, Bove F, Conte A, Dall'Occhio C, Arbasino C, Defazio G, Fiorio M, Berardelli A. Tactile and proprioceptive temporal discrimination are impaired in functional tremor. PLoS One 2014; 9:e102328. [PMID: 25051180 PMCID: PMC4106827 DOI: 10.1371/journal.pone.0102328] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Accepted: 06/12/2014] [Indexed: 11/18/2022] Open
Abstract
Background and Methods In order to obtain further information on the pathophysiology of functional tremor, we assessed tactile discrimination threshold and proprioceptive temporal discrimination motor threshold values in 11 patients with functional tremor, 11 age- and sex-matched patients with essential tremor and 13 healthy controls. Results Tactile discrimination threshold in both the right and left side was significantly higher in patients with functional tremor than in the other groups. Proprioceptive temporal discrimination threshold for both right and left side was significantly higher in patients with functional and essential tremor than in healthy controls. No significant correlation between discrimination thresholds and duration or severity of tremor was found. Conclusions Temporal processing of tactile and proprioceptive stimuli is impaired in patients with functional tremor. The mechanisms underlying this impaired somatosensory processing and possible ways to apply these findings clinically merit further research.
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Affiliation(s)
- Michele Tinazzi
- Department of Neurological and Movement Sciences, University of Verona, Verona, Italy
| | - Alfonso Fasano
- Division of Neurology, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
| | - Alessia Peretti
- Department of Neurological and Movement Sciences, University of Verona, Verona, Italy
| | - Francesco Bove
- Department of Neurology, Università Cattolica, Rome, Italy
| | - Antonella Conte
- Department of Neurology and Psychiatry, Sapienza, University of Rome and IRCCS INM Neuromed, Pozzilli, Italy
| | | | - Carla Arbasino
- Division of Neurology, Ospedale di Voghera, Voghera, Italy
| | - Giovanni Defazio
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, University of Bari, Bari, Italy
| | - Mirta Fiorio
- Department of Neurological and Movement Sciences, University of Verona, Verona, Italy
| | - Alfredo Berardelli
- Department of Neurology and Psychiatry, Sapienza, University of Rome and IRCCS INM Neuromed, Pozzilli, Italy
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Abstract
PURPOSE OF REVIEW The purpose of this review is to provide an update on the classification, phenomenology, pathophysiology, and treatment of dystonia. RECENT FINDINGS A revised definition based on the main phenomenologic features of dystonia has recently been developed in an expert consensus approach. Classification is based on two main axes: clinical features and etiology. Currently, genes have been reported for 14 types of monogenic isolated and combined dystonia. Isolated dystonia (with dystonic tremor) can be caused by mutations in TOR1A (DYT1), TUBB4 (DYT4), THAP1 (DYT6), PRKRA (DYT16), CIZ1 (DYT23), ANO3 (DYT24), and GNAL (DYT25). Combined dystonias (with parkinsonism or myoclonus) are further subdivided into persistent (GCHI [DYT5], SGCE [DYT11], and ATP1A3 [DYT12], with TAF1 most likely but not yet proven to be linked to DYT3) and paroxysmal (PNKD [DYT8], PRRT2 [DYT10], and SLC2A1 [DYT18]). Recent insights from neurophysiologic studies identified functional abnormalities in two networks in dystonia: the basal ganglia-sensorimotor network and, more recently, the cerebellothalamocortical pathway. Besides the well-known lack of inhibition at different CNS levels, dystonia is specifically characterized by maladaptive plasticity in the sensorimotor cortex and loss of cortical surround inhibition. The exact role (modulatory or compensatory) of the cerebellar-cortical pathways still has to be further elucidated. In addition to botulinum toxin for focal forms, deep brain stimulation of the globus pallidus internus is increasingly recognized as an effective treatment for generalized and segmental dystonia. SUMMARY The revised classification and identification of new genes for different forms of dystonia, including adult-onset segmental dystonia, enable an improved diagnostic approach. Recent pathophysiologic insights have fundamentally contributed to a better understanding of the disease mechanisms and impact on treatment, such as functional neurosurgery and nonpharmacologic treatment options.
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Abstract
PURPOSE OF REVIEW This review describes the main clinical features of psychogenic (functional) movement disorders and reports recent advances in diagnosis, pathophysiology, and treatment. RECENT FINDINGS The terminology and definition of patients with psychogenic movement disorders remain subjects of controversy; the term "functional" has been used more frequently in the literature in recent years regarding the neurobiological substrate underpinning these disorders. Correct diagnosis of psychogenic movement disorders should rely not on the exclusion of organic disorders or the sole presence of psychological factors but on the observation or elicitation of clinical features related to the specific movement disorder (ie, a positive or inclusionary rather than exclusionary diagnosis). Sudden onset, spontaneous remissions, and variability over time or during clinical examination are useful "red flags" suggestive of a psychogenic movement disorder. Imaging studies have demonstrated impaired connectivity between limbic and motor areas involved in movement programming and hypoactivity of a brain region that compares expected data with actual sensory data occurring during voluntary movement. Treatment of psychogenic movement disorders begins with ensuring the patient's acceptance of the diagnosis during the initial debriefing and includes nonpharmacologic (cognitive-behavioral therapy, physiotherapy) and pharmacologic options. SUMMARY Psychogenic movement disorders represent a challenging disorder for neurologists to diagnose and treat. Recent advances have increased understanding of the neurobiological mechanism of psychogenic movement disorders. Treatment with cognitive strategies and physical rehabilitation can benefit some patients. As short duration of disease correlates with better prognosis, early diagnosis and initiation of treatment are critical.
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Ganos C, Edwards MJ, Bhatia KP. The Phenomenology of Functional (Psychogenic) Dystonia. Mov Disord Clin Pract 2014; 1:36-44. [PMID: 30363921 PMCID: PMC6183180 DOI: 10.1002/mdc3.12013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 02/21/2014] [Accepted: 02/24/2014] [Indexed: 12/29/2022] Open
Abstract
From the very first descriptions of dystonia, there has been a lack of agreement on the differentiation of organic from functional (psychogenic) dystonia. This lack of agreement has had a significant effect on patients over the years, most particularly in the lack of access to appropriate management, whether for those with organic dystonia diagnosed as having a functional cause or vice versa. However, clinico-genetic advances have led to greater certainty about the phenomenology of organic dystonia and therefore recognition of atypical forms. The diagnosis of functional dystonia rests on recognition of its phenomenology and should not be, as far as possible, a diagnosis of exclusion. Here, we present an overview of the phenomenology of functional dystonia, concentrating on the three main phenotypic presentations: functional cranial dystonia; functional fixed dystonia; and functional paroxysmal dystonia. We hope that this review of phenomenology will aid in the positive diagnosis of functional dystonia and, through this, will lead to more rapid access to appropriate management.
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Affiliation(s)
- Christos Ganos
- Sobell Department of Motor Neuroscience and Movement DisordersUCL Institute of NeurologyUniversity College LondonLondonUnited Kingdom
- Department of NeurologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
- Department of Pediatric and Adult Movement Disorders and NeuropsychiatryInstitute of NeurogeneticsUniversity of LübeckLübeckGermany
| | - Mark J. Edwards
- Sobell Department of Motor Neuroscience and Movement DisordersUCL Institute of NeurologyUniversity College LondonLondonUnited Kingdom
| | - Kailash P. Bhatia
- Sobell Department of Motor Neuroscience and Movement DisordersUCL Institute of NeurologyUniversity College LondonLondonUnited Kingdom
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Abstract
Movement disorders, which include disorders such as Parkinson's disease, dystonia, Tourette's syndrome, restless legs syndrome, and akathisia, have traditionally been considered to be disorders of impaired motor control resulting predominantly from dysfunction of the basal ganglia. This notion has been revised largely because of increasing recognition of associated behavioural, psychiatric, autonomic, and other non-motor symptoms. The sensory aspects of movement disorders include intrinsic sensory abnormalities and the effects of external sensory input on the underlying motor abnormality. The basal ganglia, cerebellum, thalamus, and their connections, coupled with altered sensory input, seem to play a key part in abnormal sensorimotor integration. However, more investigation into the phenomenology and physiological basis of sensory abnormalities, and about the role of the basal ganglia, cerebellum, and related structures in somatosensory processing, and its effect on motor control, is needed.
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Affiliation(s)
- Neepa Patel
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA.
| | - Mark Hallett
- Human Motor Control Section, NINDS, National Institutes of Health, Bethesda, MD, USA
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Impaired temporal processing of tactile and proprioceptive stimuli in cerebellar degeneration. PLoS One 2013; 8:e78628. [PMID: 24244328 PMCID: PMC3823840 DOI: 10.1371/journal.pone.0078628] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 09/13/2013] [Indexed: 12/03/2022] Open
Abstract
Performance of timed motor sequences relies on the cerebellum and basal ganglia, which integrate proprioceptive information during the motor task and set internal timing mechanisms. Accordingly, these structures are also involved in other temporal processes, such as the discrimination of the different afferent information in the domain of time. In the present study we tested temporal processing of proprioceptive and tactile stimuli in 20 patients with neurodegenerative cerebellar ataxia and 20 age- and sex-matched healthy subjects. Tactile temporal discrimination threshold was defined as the value at which subjects recognized the two stimuli as asynchronous. Temporal discrimination movement threshold of the first dorsal interosseous and flexor carpi radialis was defined as the shortest interval between two paired electrical stimuli in which the subjects blindfolded perceived two separate index finger abductions and wrist flexions. Both tactile and movement temporal discrimination thresholds were higher in patients with cerebellar ataxia. No correlation was found with disease duration and severity. Our study demonstrates that temporal processing of tactile and proprioceptive stimuli is impaired in patients with cerebellar neurodegeneration and highlights the involvement of cerebellum in temporal processing of somatosensory stimuli of different type.
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Abstract
The neurobiological basis of psychogenic movement disorders (PMDs) has been elusive, and they remain difficult to treat. In the last few years, functional neuroimaging studies have provided insight into their pathophysiology and neural correlates. Here, we review the various methodological approaches that have been used in both clinical and research practice to address neural correlates of functional disorders. We then review the dominant hypotheses generated from the literature on psychogenic paralysis. Overall, these studies emphasize abnormalities in the prefrontal and anterior cingulate cortices. Recently, functional neuroimaging has been used to specifically examine PMDs. These studies have addressed a major point of controversy: whether higher frontal brain areas are directly responsible for inhibiting motor areas or whether they reflect modulation by attentional and/or emotional processes. In addition to elucidating the mechanism and cause, recent work has also explored the lack of agency that characterizes PMDs. We describe the results and implications of the results of these imaging studies and discuss possible interpretations.
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Affiliation(s)
- Arpan R. Mehta
- Division of Clinical Neurology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - James B. Rowe
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK
- Behavioural and Clinical Neuroscience Institute, Cambridge, UK
| | - Anette E. Schrag
- Institute of Neurology, Royal Free Campus, University College London, London, UK
- UCL Institute of Neurology, University College London, Royal Free Campus, Clinical Neurosciences, Rowland Hill Street, London, NW3 2PF UK
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Garcin B, Roze E, Mesrati F, Cognat E, Fournier E, Vidailhet M, Degos B. Transcranial magnetic stimulation as an efficient treatment for psychogenic movement disorders. J Neurol Neurosurg Psychiatry 2013; 84:1043-6. [PMID: 23385844 DOI: 10.1136/jnnp-2012-304062] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Management of psychogenic movement disorders (PMDs) is challenging for neurologists and, to date, there is no consensus about their treatment. Recent studies suggested a possible therapeutic effect of repeated transcranial magnetic stimulation (TMS) in psychogenic paralysis and tremor. OBJECTIVE To document the clinical impact of TMS in PMDs. METHODS We blindly video scored symptoms of consecutive patients with PMD who were recorded before and after TMS. TMS was delivered at low frequency (0.25 Hz) over the motor cortex contralateral to symptoms. RESULTS Twenty-four patients were included. They presented with dystonia, myoclonus, tremor, Parkinsonism or stereotypies. The median duration of symptoms before TMS was 2.8 years (6 months to 30 years). The overall score of 75% of patients improved by >50% and, furthermore, the clinical benefits were sustained upon protracted follow-up (median 19.8 months). There was no correlation between improvement and duration of symptoms before TMS. CONCLUSIONS TMS is a therapeutic option for PMDs, including chronic PMDs.
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Affiliation(s)
- Béatrice Garcin
- Département de Neurologie, Hôpital Pitié-Salpêtrière, Centre de Référence Maladie de Parkinson, APHP, Paris, France
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Conte A, Defazio G, Ferrazzano G, Hallett M, Macerollo A, Fabbrini G, Berardelli A. Is increased blinking a form of blepharospasm? Neurology 2013; 80:2236-41. [PMID: 23751916 DOI: 10.1212/wnl.0b013e318296e99d] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The aim of this study was to investigate whether increased blink rate (BR) is part of the clinical spectrum of primary blepharospasm (BSP). METHODS We enrolled 40 patients (16 patients with an increased BR but without typical orbicularis oculi [OO] spasms, and 24 patients with typical involuntary OO spasms) and 18 healthy subjects. The BR, blink reflex recovery cycle, and somatosensory temporal discrimination threshold (STDT) were tested in patients and controls. RESULTS Patients who had typical OO spasms had an altered R2 recovery cycle whereas those who had an increased BR alone had a normal blink reflex recovery cycle. STDT values were higher in patients than in healthy subjects and no difference was found in the STDT abnormalities in the 2 groups of patients. CONCLUSIONS Our study shows that, despite the similar STDT abnormalities, the different changes in the R2 recovery cycle in patients with BSP and those with increased BR alone suggest that these disorders arise from different pathologic mechanisms.
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Affiliation(s)
- Antonella Conte
- Department of Neurology and Psychiatry, Sapienza University of Rome, Italy
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Konczak J, Abbruzzese G. Focal dystonia in musicians: linking motor symptoms to somatosensory dysfunction. Front Hum Neurosci 2013; 7:297. [PMID: 23805090 PMCID: PMC3691509 DOI: 10.3389/fnhum.2013.00297] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 06/05/2013] [Indexed: 11/29/2022] Open
Abstract
Musician's dystonia (MD) is a neurological motor disorder characterized by involuntary contractions of those muscles involved in the play of a musical instrument. It is task-specific and initially only impairs the voluntary control of highly practiced musical motor skills. MD can lead to a severe decrement in a musician's ability to perform. While the etiology and the neurological pathomechanism of the disease remain unknown, it is known that MD like others forms of focal dystonia is associated with somatosensory deficits, specifically a decreased precision of tactile and proprioceptive perception. The sensory component of the disease becomes also evident by the patients' use of “sensory tricks” such as touching dystonic muscles to alleviate motor symptoms. The central premise of this paper is that the motor symptoms of MD have a somatosensory origin and are not fully explained as a problem of motor execution. We outline how altered proprioceptive feedback ultimately leads to a loss of voluntary motor control and propose two scenarios that explain why sensory tricks are effective. They are effective, because the sensorimotor system either recruits neural resources normally involved in tactile-proprioceptive (sensory) integration, or utilizes a fully functioning motor efference copy mechanism to align experienced with expected sensory feedback. We argue that an enhanced understanding of how a primary sensory deficit interacts with mechanisms of sensorimotor integration in MD provides helpful insights for the design of more effective behavioral therapies.
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Affiliation(s)
- Jürgen Konczak
- Human Sensorimotor Control Laboratory, Center for Clinical Movement Science, School of Kinesiology, University of Minnesota Minneapolis, MN, USA
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Somatosensory Temporal Discrimination Threshold Is Increased in Patients with Cerebellar Atrophy. THE CEREBELLUM 2013; 12:456-9. [DOI: 10.1007/s12311-012-0435-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
PURPOSE OF REVIEW This review provides an overview of recent developments in diagnosis, pathophysiology, neuroimaging and management of functional (psychogenic) movement disorders (FMD). RECENT FINDINGS There has been increasing interest to study the underlying pathophysiology of FMD, which has resulted in a broadened disease model, taking neurobiologic and psychosocial factors equally into account. In this context, the term 'psychogenic' has been replaced by 'functional' movement disorders by many authors in the field to express the changing focus toward a multifactorial disease model. The need for establishing a positive diagnosis of FMD as opposed to providing a diagnosis of exclusion is increasingly recognized and reflected by the introduction of 'laboratory-supported' diagnostic criteria of FMD. Important advances have been made through behavioral, electrophysiological and neuroimaging studies, although the fundamental cause of FMD remains poorly understood. Of particular interest have been several reports on abnormal sensorimotor features and cortical inhibition in both organic and functional dystonia, highlighting possible shared traits of both conditions. In terms of treatment, recent studies have reported benefit from both psychiatric and physical therapy-based interventions. SUMMARY Increasing efforts have been made toward better understanding of FMD, and the disease model has been broadened to include neurobiologic and psychosocial factors. Laboratory-based diagnostic criteria have been established for many FMD to support the clinical diagnosis. To determine the most effective management strategies for FMD, a closer collaboration between neurologists and psychiatrists and intensified research efforts with prospective treatment trials are needed.
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Affiliation(s)
- Kathrin Czarnecki
- Human Motor Control Section, NINDS, NIH, Bethesda, Maryland 20892-1428, USA
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