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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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2
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Belvisi D, Leodori G, Costanzo M, Conte A, Berardelli A. How does botulinum toxin really work? INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 169:441-479. [PMID: 37482400 DOI: 10.1016/bs.irn.2023.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Over the past 30 years, Botulinum toxin (BoNT) has emerged as an effective and safe therapeutic tool for a number of neurological conditions, including dystonia. To date, the exact mechanism of action of BoNT in dystonia is not fully understood. Although it is well known that BoNT mainly acts on the neuromuscular junction, a growing body of evidence suggests that the therapeutic effect of BoNT in dystonia may also depend on its ability to modulate peripheral sensory feedback from muscle spindles. Animal models also suggest a retrograde and anterograde BoNT transportation from the site of injection to central nervous system structures. In humans, however, BoNT central effects seem to depend on the modulation of afferent input rather than on BoNT transportation. In this chapter, we aimed to report and discuss research evidence providing information on the possible mechanisms of action of BoNT in relation to treatment of dystonia.
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Affiliation(s)
- Daniele Belvisi
- Department of Human Neurosciences, Sapienza, University of Rome, Viale dell' Università 30, Rome, Italy; IRCCS Neuromed, via Atinense 18, Pozzilli, IS, Italy
| | - Giorgio Leodori
- Department of Human Neurosciences, Sapienza, University of Rome, Viale dell' Università 30, Rome, Italy; IRCCS Neuromed, via Atinense 18, Pozzilli, IS, Italy
| | | | - Antonella Conte
- Department of Human Neurosciences, Sapienza, University of Rome, Viale dell' Università 30, Rome, Italy; IRCCS Neuromed, via Atinense 18, Pozzilli, IS, Italy
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza, University of Rome, Viale dell' Università 30, Rome, Italy; IRCCS Neuromed, via Atinense 18, Pozzilli, IS, Italy.
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3
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Bologna M, Valls-Solè J, Kamble N, Pal PK, Conte A, Guerra A, Belvisi D, Berardelli A. Dystonia, chorea, hemiballismus and other dyskinesias. Clin Neurophysiol 2022; 140:110-125. [PMID: 35785630 DOI: 10.1016/j.clinph.2022.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/12/2022] [Accepted: 05/24/2022] [Indexed: 11/30/2022]
Abstract
Hyperkinesias are heterogeneous involuntary movements that significantly differ in terms of clinical and semeiological manifestations, including rhythm, regularity, speed, duration, and other factors that determine their appearance or suppression. Hyperkinesias are due to complex, variable, and largely undefined pathophysiological mechanisms that may involve different brain areas. In this chapter, we specifically focus on dystonia, chorea and hemiballismus, and other dyskinesias, specifically, levodopa-induced, tardive, and cranial dyskinesia. We address the role of neurophysiological studies aimed at explaining the pathophysiology of these conditions. We mainly refer to human studies using surface and invasive in-depth recordings, as well as spinal, brainstem, and transcortical reflexology and non-invasive brain stimulation techniques. We discuss the extent to which the neurophysiological abnormalities observed in hyperkinesias may be explained by pathophysiological models. We highlight the most relevant issues that deserve future research efforts. The potential role of neurophysiological assessment in the clinical context of hyperkinesia is also discussed.
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Affiliation(s)
- Matteo Bologna
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli (IS), Italy
| | - Josep Valls-Solè
- Institut d'Investigació Biomèdica August Pi I Sunyer, Villarroel, 170, Barcelona, Spain
| | - Nitish Kamble
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Bengaluru, India
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Bengaluru, India
| | - Antonella Conte
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli (IS), Italy
| | | | - Daniele Belvisi
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli (IS), Italy
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli (IS), Italy.
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Gründahl J, Großbach M, Altenmüller E. Video-based long-term follow up of musician’s dystonia in pianists reveals similar improvements following different treatment strategies: a retrospective observational study. JOURNAL OF CLINICAL MOVEMENT DISORDERS 2022. [PMCID: PMC8787894 DOI: 10.1186/s40734-021-00092-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Abstract
Background
Musician’s Dystonia (MD) by impaired or complete loss of fine motor control in extensively trained movements at the instrument. In pianists, it frequently leads to involuntary flexion or extension of one or more fingers. Treatment remains challenging, although local injections with Botulinum toxin, anticholinergic medication and pedagogical retraining seem to be helpful in individual cases. Evaluation of therapies however is frequently hampered by lack of practicability, or validity. This retrospective observational study aims to assess the long-term development of MD and efficacy of therapies in keyboard players by means of a simple video-rating procedure by informed expert raters.
Methods
Video rating is characterisedwas done by 6 carefully instructed pianists, rating a total of 266 videos from 80 patients, recorded over a period of almost 20 years. These showed the affected hand playing a C-major scale as “regularly” as possible at a moderate tempo on a grand piano. Raters assessed the acoustic irregularity of scale playing and any visible movement impairment on visual analogue scales. Influence of patient-specific factors including applied treatment was estimated in a Bayesian multilevel beta regression.
Results
For ratings of irregularity and impairment intra-rater reliability was strong and inter-rater concordance was moderate. The average estimated improvement across all therapies was 14% in irregularity and 15% in impairment. Highest improvement rates in ratings of irregularity were found after the combined treatment with Botulinum toxin and Trihexyphenidyl (45%) as well as in retraining (29% improvement) as single therapy. In ratings of impairment the highest improvement was shown for retraining in combination with Trihexyphenidyl (36% improvement) as well as retraining as single therapy (23%).
Conclusions
This study provides a new perspective on the course of MD in keyboard players in a larger cohort using methods other than self-report. Video rating of scale-playing was shown to be a reliable and useful method to evaluate MD in keyboard players. Average improvement rates were different to previous studies using patient-subjective questionnaires. Treatment options showed different effects in the two rating criteria, with retraining showing the highest improvement rates in single and combined use.
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Guidali G, Roncoroni C, Bolognini N. Paired associative stimulations: Novel tools for interacting with sensory and motor cortical plasticity. Behav Brain Res 2021; 414:113484. [PMID: 34302877 DOI: 10.1016/j.bbr.2021.113484] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 06/10/2021] [Accepted: 07/19/2021] [Indexed: 12/26/2022]
Abstract
In the early 2000s, a novel non-invasive brain stimulation protocol, the paired associative stimulation (PAS), was introduced, allowing to induce and investigate Hebbian associative plasticity within the humans' motor system, with patterns resembling spike-timing-dependent plasticity properties found in cellular models. Since this evidence, PAS efficacy has been proved in healthy, and to a lesser extent, in clinical populations. Recently, novel 'modified' protocols targeting sensorimotor and crossmodal networks appeared in the literature. In the present work, we have reviewed recent advances using these 'modified' PAS protocols targeting sensory and motor cortical networks. To better categorize them, we propose a novel classification according to the nature of the peripheral and cortical stimulations (i.e., within-system, cross-systems, and cortico-cortical PAS). For each protocol of the categories mentioned above, we describe and discuss their main features, how they have been used to study and promote brain plasticity, and their advantages and disadvantages. Overall, current evidence suggests that these novel non-invasive brain stimulation protocols represent very promising tools to study the plastic properties of humans' sensorimotor and crossmodal networks, both in the healthy and in the damaged central nervous system.
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Affiliation(s)
- Giacomo Guidali
- Neurophysiology Lab, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy; Department of Psychology & NeuroMI - Milan Center for Neuroscience, University of Milano-Bicocca, Milan, Italy.
| | - Camilla Roncoroni
- Department of Psychology & NeuroMI - Milan Center for Neuroscience, University of Milano-Bicocca, Milan, Italy
| | - Nadia Bolognini
- Department of Psychology & NeuroMI - Milan Center for Neuroscience, University of Milano-Bicocca, Milan, Italy; Laboratory of Neuropsychology, IRCCS Istituto Auxologico Italiano, Milan, Italy
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Li J, Kim S, Pappas SS, Dauer WT. CNS critical periods: implications for dystonia and other neurodevelopmental disorders. JCI Insight 2021; 6:142483. [PMID: 33616084 PMCID: PMC7934928 DOI: 10.1172/jci.insight.142483] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Critical periods are discrete developmental stages when the nervous system is especially sensitive to stimuli that facilitate circuit maturation. The distinctive landscapes assumed by the developing CNS create analogous periods of susceptibility to pathogenic insults and responsiveness to therapy. Here, we review critical periods in nervous system development and disease, with an emphasis on the neurodevelopmental disorder DYT1 dystonia. We highlight clinical and laboratory observations supporting the existence of a critical period during which the DYT1 mutation is uniquely harmful, and the implications for future therapeutic development.
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Affiliation(s)
- Jay Li
- Medical Scientist Training Program, University of Michigan, Ann Arbor, Michigan, USA.,Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, Michigan, USA
| | - Sumin Kim
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, Michigan, USA
| | - Samuel S Pappas
- Peter O'Donnell Jr. Brain Institute.,Department of Neurology, and
| | - William T Dauer
- Peter O'Donnell Jr. Brain Institute.,Department of Neurology, and.,Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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7
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Latorre A, Cocco A, Bhatia KP, Erro R, Antelmi E, Conte A, Rothwell JC, Rocchi L. Defective Somatosensory Inhibition and Plasticity Are Not Required to Develop Dystonia. Mov Disord 2020; 36:1015-1021. [PMID: 33332649 DOI: 10.1002/mds.28427] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/21/2020] [Accepted: 11/18/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Dystonia may have different neuroanatomical substrates and pathophysiology. This is supported by studies on the motor system showing, for instance, that plasticity is abnormal in idiopathic dystonia, but not in dystonia secondary to basal ganglia lesions. OBJECTIVE The aim of this study was to test whether somatosensory inhibition and plasticity abnormalities reported in patients with idiopathic dystonia also occur in patients with dystonia caused by basal ganglia damage. METHODS Ten patients with acquired dystonia as a result of basal ganglia lesions and 12 healthy control subjects were recruited. They underwent electrophysiological testing at baseline and after a single 45-minute session of high-frequency repetitive somatosensory stimulation. Electrophysiological testing consisted of somatosensory temporal discrimination, somatosensory-evoked potentials (including measurement of early and late high-frequency oscillations and the spatial inhibition ratio of N20/25 and P14 components), the recovery cycle of paired-pulse somatosensory-evoked potentials, and primary motor cortex short-interval intracortical inhibition. RESULTS Unlike previous reports of patients with idiopathic dystonia, patients with acquired dystonia did not differ from healthy control subjects in any of the electrophysiological measures either before or after high-frequency repetitive somatosensory stimulation, except for short-interval intracortical inhibition, which was reduced at baseline in patients compared to control subjects. CONCLUSIONS The data show that reduced somatosensory inhibition and enhanced cortical plasticity are not required for the clinical expression of dystonia, and that the abnormalities reported in idiopathic dystonia are not necessarily linked to basal ganglia damage. © 2020 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Antoniangela Cocco
- Department of Neurology, IRCCS Humanitas Research Hospital, Milan, Italy.,Department of Neuroscience, Catholic University, Milan, Italy
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Roberto Erro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Elena Antelmi
- Neurology Unit, Movement Disorders Division, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Antonella Conte
- Department of Human Neurosciences, Sapienza, University of Rome, Rome, Italy.,IRCCS Neuromed, Pozzilli, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
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8
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McCambridge AB, Bradnam LV. Cortical neurophysiology of primary isolated dystonia and non-dystonic adults: A meta-analysis. Eur J Neurosci 2020; 53:1300-1323. [PMID: 32991762 DOI: 10.1111/ejn.14987] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 11/30/2022]
Abstract
Transcranial magnetic stimulation (TMS) is a non-invasive method to assess neurophysiology of the primary motor cortex in humans. Dystonia is a poorly understood neurological movement disorder, often presenting in an idiopathic, isolated form across different parts of the body. The neurophysiological profile of isolated dystonia compared to healthy adults remains unclear. We conducted a systematic review with meta-analysis of neurophysiologic TMS measures in people with isolated dystonia to provide a synthesized understanding of cortical neurophysiology associated with isolated dystonia. We performed a systematic database search and data were extracted independently by the two authors. Separate meta-analyses were performed for TMS measures of: motor threshold, corticomotor excitability, short interval intracortical inhibition, cortical silent period, intracortical facilitation and afferent-induced inhibition. Standardized mean differences were calculated using a random effects model to determine overall effect sizes and confidence intervals. Heterogeneity was explored using dystonia type subgroup analysis. The search resulted in 78 studies meeting inclusion criteria, of these 57 studies reported data in participants with focal hand dystonia, cervical dystonia, blepharospasm or spasmodic dysphonia, and were included in at least one meta-analysis. The cortical silent period, short-interval intracortical inhibition and afferent-induced inhibition was found to be reduced in isolated dystonia compared to controls. Reduced GABAergic-mediated inhibition in the primary motor cortex in idiopathic isolated dystonia's suggest interventions targeted to aberrant cortical disinhibition could provide a novel treatment. Future meta-analyses require neurophysiology studies to use homogeneous cohorts of isolated dystonia participants, publish raw data values, and record electromyographic responses from dystonic musculature where possible.
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Affiliation(s)
- Alana B McCambridge
- Graduate School of Health, Discipline of Physiotherapy, University of Technology Sydney, Sydney, NSW, Australia
| | - Lynley V Bradnam
- Department of Exercise Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
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9
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De Bartolo MI, Manzo N, Ferrazzano G, Baione V, Belvisi D, Fabbrini G, Berardelli A, Conte A. Botulinum Toxin Effects on Sensorimotor Integration in Focal Dystonias. Toxins (Basel) 2020; 12:toxins12050277. [PMID: 32344856 PMCID: PMC7290883 DOI: 10.3390/toxins12050277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 12/04/2022] Open
Abstract
(1) Background: In dystonia, the somatosensory temporal discrimination threshold (STDT) is abnormally increased at rest and higher and longer-lasting during movement execution in comparison with healthy subjects (HS), suggesting an abnormal sensorimotor integration. These abnormalities are thought to depend on abnormal proprioceptive input coming from dystonic muscles. Since Botulinum toxin-A (BT-A) reduces proprioceptive input in the injected muscles, our study investigated the effects of BT-A on STDT tested at rest and during voluntary movement execution in patients with focal dystonia. (2) Methods: We enrolled 35 patients with focal dystonia: 14 patients with cervical dystonia (CD), 11 patients with blepharospasm (BSP), and 10 patients with focal hand dystonia (FHD); and 12 age-matched HS. STDT tested by delivering paired stimuli was measured in all subjects at rest and during index finger abductions. (3) Results: Patients with dystonia had higher STDT values at rest and during movement execution than HS. While BT-A did not modify STDT at rest, it reduced the abnormal values of STDT during movement in CD and FHD patients, but not in BSP patients. (4) Conclusions: BT-A improved abnormal sensorimotor integration in CD and FHD, most likely by decreasing the overflow of proprioceptive signaling from muscle dystonic activity to the thalamus.
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Affiliation(s)
- Maria Ilenia De Bartolo
- IRCCS NEUROMED, Via Atinense, 18, 86077 Pozzilli (IS), Italy; (M.I.D.B.); (N.M.); (D.B.); (G.F.); (A.C.)
| | - Nicoletta Manzo
- IRCCS NEUROMED, Via Atinense, 18, 86077 Pozzilli (IS), Italy; (M.I.D.B.); (N.M.); (D.B.); (G.F.); (A.C.)
| | - Gina Ferrazzano
- Department of Human Neuroscience, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (V.B.)
| | - Viola Baione
- Department of Human Neuroscience, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (V.B.)
| | - Daniele Belvisi
- IRCCS NEUROMED, Via Atinense, 18, 86077 Pozzilli (IS), Italy; (M.I.D.B.); (N.M.); (D.B.); (G.F.); (A.C.)
| | - Giovanni Fabbrini
- IRCCS NEUROMED, Via Atinense, 18, 86077 Pozzilli (IS), Italy; (M.I.D.B.); (N.M.); (D.B.); (G.F.); (A.C.)
- Department of Human Neuroscience, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (V.B.)
| | - Alfredo Berardelli
- IRCCS NEUROMED, Via Atinense, 18, 86077 Pozzilli (IS), Italy; (M.I.D.B.); (N.M.); (D.B.); (G.F.); (A.C.)
- Department of Human Neuroscience, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (V.B.)
- Correspondence:
| | - Antonella Conte
- IRCCS NEUROMED, Via Atinense, 18, 86077 Pozzilli (IS), Italy; (M.I.D.B.); (N.M.); (D.B.); (G.F.); (A.C.)
- Department of Human Neuroscience, Sapienza University of Rome, 00185 Rome, Italy; (G.F.); (V.B.)
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Plasticity and dystonia: a hypothesis shrouded in variability. Exp Brain Res 2020; 238:1611-1617. [PMID: 32206849 PMCID: PMC7413892 DOI: 10.1007/s00221-020-05773-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/07/2020] [Indexed: 12/19/2022]
Abstract
Studying plasticity mechanisms with Professor John Rothwell was a shared highlight of our careers. In this article, we discuss non-invasive brain stimulation techniques which aim to induce and quantify plasticity, the mechanisms and nature of their inherent variability and use such observations to review the idea that excessive and abnormal plasticity is a pathophysiological substrate of dystonia. We have tried to define the tone of our review by a couple of Professor John Rothwell's many inspiring characteristics; his endless curiosity to refine knowledge and disease models by scientific exploration and his wise yet humble readiness to revise scientific doctrines when the evidence is supportive. We conclude that high variability of response to non-invasive brain stimulation plasticity protocols significantly clouds the interpretation of historical findings in dystonia research. There is an opportunity to wipe the slate clean of assumptions and armed with an informative literature in health, re-evaluate whether excessive plasticity has a causal role in the pathophysiology of dystonia.
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Conte A, Defazio G, Mascia M, Belvisi D, Pantano P, Berardelli A. Advances in the pathophysiology of adult-onset focal dystonias: recent neurophysiological and neuroimaging evidence. F1000Res 2020; 9. [PMID: 32047617 PMCID: PMC6993830 DOI: 10.12688/f1000research.21029.2] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/23/2020] [Indexed: 12/28/2022] Open
Abstract
Focal dystonia is a movement disorder characterized by involuntary muscle contractions that determine abnormal postures. The traditional hypothesis that the pathophysiology of focal dystonia entails a single structural dysfunction (i.e. basal ganglia) has recently come under scrutiny. The proposed network disorder model implies that focal dystonias arise from aberrant communication between various brain areas. Based on findings from animal studies, the role of the cerebellum has attracted increased interest in the last few years. Moreover, it has been increasingly reported that focal dystonias also include nonmotor disturbances, including sensory processing abnormalities, which have begun to attract attention. Current evidence from neurophysiological and neuroimaging investigations suggests that cerebellar involvement in the network and mechanisms underlying sensory abnormalities may have a role in determining the clinical heterogeneity of focal dystonias.
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Affiliation(s)
- Antonella Conte
- Department of Human Neurosciences, Sapienza, University of Rome, Rome, Italy.,IRCCS Neuromed, Pozzilli (IS), Italy
| | - Giovanni Defazio
- Department of Medical Sciences and Public Health, Neurology Unit, University of Cagliari and AOU Cagliari, Monserrato, Cagliari, Italy
| | - Marcello Mascia
- Department of Medical Sciences and Public Health, Neurology Unit, University of Cagliari and AOU Cagliari, Monserrato, Cagliari, Italy
| | | | - Patrizia Pantano
- Department of Human Neurosciences, Sapienza, University of Rome, Rome, Italy.,IRCCS Neuromed, Pozzilli (IS), Italy
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza, University of Rome, Rome, Italy.,IRCCS Neuromed, Pozzilli (IS), Italy
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12
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Gövert F, Becktepe J, Balint B, Rocchi L, Brugger F, Garrido A, Walter T, Hannah R, Rothwell J, Elble R, Deuschl G, Bhatia K. Temporal discrimination is altered in patients with isolated asymmetric and jerky upper limb tremor. Mov Disord 2019; 35:306-315. [PMID: 31724777 DOI: 10.1002/mds.27880] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 09/01/2019] [Accepted: 09/16/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Unilateral or very asymmetric upper limb tremors with a jerky appearance are poorly investigated. Their clinical classification is an unsolved problem because their classification as essential tremor versus dystonic tremor is uncertain. To avoid misclassification as essential tremor or premature classification as dystonic tremor, the term indeterminate tremor was suggested. OBJECTIVES The aim of this study was to characterize this tremor subgroup electrophysiologically and evaluate whether diagnostically meaningful electrophysiological differences exist compared to patients with essential tremor and dystonic tremor. METHODS We enrolled 29 healthy subjects and 64 patients with tremor: 26 with dystonic tremor, 23 with essential tremor, and 15 patients with upper limb tremor resembling essential tremor but was unusually asymmetric and jerky (indeterminate tremor). We investigated the somatosensory temporal discrimination threshold, the short-interval intracortical inhibition, and the cortical plasticity by paired associative stimulation. RESULTS Somatosensory temporal discrimination threshold was significantly increased in patients with dystonic tremor and indeterminate tremor, but it was normal in the essential tremor patients and healthy controls. Significant differences in short-interval intracortical inhibition and paired associative stimulation were not found among the three patient groups and controls. CONCLUSION These results indicate that indeterminate tremor, as defined in this study, shares electrophysiological similarities with dystonic tremor rather than essential tremor. Therefore, we propose that indeterminate tremor should be considered as a separate clinical entity from essential tremor and that it might be dystonic in nature. Somatosensory temporal discrimination appears to be a useful tool in tremor classification. © 2019 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Felix Gövert
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts-University, Kiel, Germany.,Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Jos Becktepe
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts-University, Kiel, Germany
| | - Bettina Balint
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom.,Department of Neurology, University Hospital Heidelberg, Heidelberg, Germany
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Florian Brugger
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom.,Department of Neurology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Alicia Garrido
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom.,Movement Disorders Unit, Neurology Service, Hospital Clínic, Institut d'investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Barcelona, Spain
| | - Tim Walter
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts-University, Kiel, Germany
| | - Ricci Hannah
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - John Rothwell
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Rodger Elble
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Günther Deuschl
- Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts-University, Kiel, Germany
| | - Kailash Bhatia
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom
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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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14
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Latorre A, Rocchi L, Berardelli A, Bhatia KP, Rothwell JC. The interindividual variability of transcranial magnetic stimulation effects: Implications for diagnostic use in movement disorders. Mov Disord 2019; 34:936-949. [DOI: 10.1002/mds.27736] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 05/09/2019] [Accepted: 05/16/2019] [Indexed: 11/08/2022] Open
Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement NeurosciencesQueen Square Institute of Neurology University College London London United Kingdom
- Department of Neurology and Psychiatry, SapienzaUniversity of Rome Rome Italy
| | - Lorenzo Rocchi
- Department of Clinical and Movement NeurosciencesQueen Square Institute of Neurology University College London London United Kingdom
| | - Alfredo Berardelli
- Department of Neurology and Psychiatry, SapienzaUniversity of Rome Rome Italy
- Istituto di Ricovero e Cura a Carattere Scientifico Neuromed Pozzilli Isernia Italy
| | - Kailash P. Bhatia
- Department of Clinical and Movement NeurosciencesQueen Square Institute of Neurology University College London London United Kingdom
| | - John C. Rothwell
- Department of Clinical and Movement NeurosciencesQueen Square Institute of Neurology University College London London United Kingdom
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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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Differential effects of propranolol on head and upper limb tremor in patients with essential tremor and dystonia. J Neurol 2018; 265:2695-2703. [PMID: 30209649 DOI: 10.1007/s00415-018-9052-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 09/04/2018] [Accepted: 09/06/2018] [Indexed: 01/19/2023]
Abstract
Propranolol is used as the first-line treatment in essential tremor and it has also been proposed as a treatment for tremor in dystonia. However, several issues remain uncertain. For example, it is still not clear whether propranolol exerts a beneficial effect on head tremor. Moreover, no studies have investigated whether the effect of propranolol on head and upper limb tremor in essential tremor differs from that in dystonia. We aimed to assess the effects of propranolol on tremor in different body parts in essential tremor and in patients with tremor and dystonia. Twenty-nine patients with head and upper limb tremor were enrolled in the study, 14 with essential tremor, and 15 with dystonia. Participants underwent a clinical and kinematic analysis of tremor in two sessions, i.e., without (baseline) and 'on therapy' with propranolol. We found that head tremor was more severe in patients with dystonia, while upper limb tremor was more evident in patients with essential tremor (P < 0.05). Propranolol had no effect on head tremor in either group (all Ps > 0.05), but it did reduce upper limb tremor in patients with essential tremor. The present study demonstrates differential effects of propranolol on head and upper limb tremor in patients with essential tremor. The lack of effect on head and upper limb tremor in patients with dystonia suggests that the pathophysiological mechanisms underlying tremor in these two conditions and in different body parts may be distinct.
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Disrupted superior collicular activity may reveal cervical dystonia disease pathomechanisms. Sci Rep 2017; 7:16753. [PMID: 29196716 PMCID: PMC5711841 DOI: 10.1038/s41598-017-17074-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 11/21/2017] [Indexed: 11/13/2022] Open
Abstract
Cervical dystonia is a common neurological movement disorder characterised by muscle contractions causing abnormal movements and postures affecting the head and neck. The neural networks underpinning this condition are incompletely understood. While animal models suggest a role for the superior colliculus in its pathophysiology, this link has yet to be established in humans. The present experiment was designed to test the hypothesis that disrupted superior collicular processing is evident in affected patients and in relatives harbouring a disease-specific endophenotype (abnormal temporal discrimination). The study participants were 16 cervical dystonia patients, 16 unaffected first-degree relatives with abnormal temporal discrimination, 16 unaffected first-degree relatives with normal temporal discrimination and 16 healthy controls. The response of participant’s superior colliculi to looming stimuli was assessed by functional magnetic resonance imaging. Cervical dystonia patients and relatives with abnormal temporal discrimination demonstrated (i) significantly reduced superior collicular activation for whole brain and region of interest analysis; (ii) a statistically significant negative correlation between temporal discrimination threshold and superior collicular peak values. Our results support the hypothesis that disrupted superior collicular processing is involved in the pathogenesis of cervical dystonia. These findings, which align with animal models of cervical dystonia, shed new light on pathomechanisms in humans.
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18
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Suppa A, Quartarone A, Siebner H, Chen R, Di Lazzaro V, Del Giudice P, Paulus W, Rothwell J, Ziemann U, Classen J. The associative brain at work: Evidence from paired associative stimulation studies in humans. Clin Neurophysiol 2017; 128:2140-2164. [DOI: 10.1016/j.clinph.2017.08.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/20/2017] [Accepted: 08/03/2017] [Indexed: 12/25/2022]
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19
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Does the Somatosensory Temporal Discrimination Threshold Change over Time in Focal Dystonia? Neural Plast 2017; 2017:9848070. [PMID: 29062576 PMCID: PMC5618781 DOI: 10.1155/2017/9848070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 08/23/2017] [Indexed: 11/20/2022] Open
Abstract
Background The somatosensory temporal discrimination threshold (STDT) is defined as the shortest interval at which an individual recognizes two stimuli as asynchronous. Some evidence suggests that STDT depends on cortical inhibitory interneurons in the basal ganglia and in primary somatosensory cortex. Several studies have reported that the STDT in patients with dystonia is abnormal. No longitudinal studies have yet investigated whether STDT values in different forms of focal dystonia change during the course of the disease. Methods We designed a follow-up study on 25 patients with dystonia (15 with blepharospasm and 10 with cervical dystonia) who were tested twice: upon enrolment and 8 years later. STDT values from dystonic patients at the baseline were also compared with those from a group of 30 age-matched healthy subjects. Results Our findings show that the abnormally high STDT values observed in patients with focal dystonia remained unchanged at the 8-year follow-up assessment whereas disease severity worsened. Conclusions Our observation that STDT abnormalities in dystonia remain unmodified during the course of the disease suggests that the altered activity of inhibitory interneurons—either at cortical or at subcortical level—responsible for the increased STDT does not deteriorate as the disease progresses.
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20
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Fassett HJ, Turco CV, El-Sayes J, Lulic T, Baker S, Richardson B, Nelson AJ. Transcranial Magnetic Stimulation with Intermittent Theta Burst Stimulation Alters Corticospinal Output in Patients with Chronic Incomplete Spinal Cord Injury. Front Neurol 2017; 8:380. [PMID: 28824536 PMCID: PMC5543286 DOI: 10.3389/fneur.2017.00380] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 07/18/2017] [Indexed: 12/02/2022] Open
Abstract
Intermittent theta burst stimulation (iTBS) is intended primarily to alter corticospinal excitability, creating an attractive opportunity to alter neural output following incomplete spinal cord injury (SCI). This study is the first to assess the effects of iTBS in SCI. Eight individuals with chronic incomplete SCI were studied. Sham or real iTBS was delivered (to each participant) over primary motor and somatosensory cortices in separate sessions. Motor-evoked potential (MEP) recruitment curves were obtained from the flexor carpi radialis muscle before and after iTBS. Results indicate similar responses for iTBS to both motor and somatosensory cortex and reduced MEPs in 56.25% and increased MEPs in 25% of instances. Sham stimulation exceeded real iTBS effects in the remaining 18.25%. It is our opinion that observing short-term neuroplasticity in corticospinal output in chronic SCI is an important advance and should be tested in future studies as an opportunity to improve function in this population. We emphasize the need to re-consider the importance of the direction of MEP change following a single session of iTBS since the relationship between MEP direction and motor function is unknown and multiple sessions of iTBS may yield very different directional results. Furthermore, we highlight the importance of including sham control in the experimental design. The fundamental point from this pilot research is that a single session of iTBS is often capable of creating short-term change in SCI. Future sham-controlled randomized trials may consider repeat iTBS sessions to promote long-term changes in corticospinal excitability.
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Affiliation(s)
- Hunter J Fassett
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Claudia V Turco
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Jenin El-Sayes
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Tea Lulic
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Steve Baker
- Division of Physical Medicine and Rehabilitation, Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - Brian Richardson
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Aimee J Nelson
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
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21
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Pirio Richardson S, Altenmüller E, Alter K, Alterman RL, Chen R, Frucht S, Furuya S, Jankovic J, Jinnah HA, Kimberley TJ, Lungu C, Perlmutter JS, Prudente CN, Hallett M. Research Priorities in Limb and Task-Specific Dystonias. Front Neurol 2017; 8:170. [PMID: 28515706 PMCID: PMC5413505 DOI: 10.3389/fneur.2017.00170] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 04/11/2017] [Indexed: 11/13/2022] Open
Abstract
Dystonia, which causes intermittent or sustained abnormal postures and movements, can present in a focal or a generalized manner. In the limbs, focal dystonia can occur in either the upper or lower limbs and may be task-specific causing abnormal motor performance for only a specific task, such as in writer’s cramp, runner’s dystonia, or musician’s dystonia. Focal limb dystonia can be non-task-specific and may, in some circumstances, be associated with parkinsonian disorders. The true prevalence of focal limb dystonia is not known and is likely currently underestimated, leaving a knowledge gap and an opportunity for future research. The pathophysiology of focal limb dystonia shares some commonalities with other dystonias with a loss of inhibition in the central nervous system and a loss of the normal regulation of plasticity, called homeostatic plasticity. Functional imaging studies revealed abnormalities in several anatomical networks that involve the cortex, basal ganglia, and cerebellum. Further studies should focus on distinguishing cause from effect in both physiology and imaging studies to permit focus on most relevant biological correlates of dystonia. There is no specific therapy for the treatment of limb dystonia given the variability in presentation, but off-label botulinum toxin therapy is often applied to focal limb and task-specific dystonia. Various rehabilitation techniques have been applied and rehabilitation interventions may improve outcomes, but small sample size and lack of direct comparisons between methods to evaluate comparative efficacy limit conclusions. Finally, non-invasive and invasive therapeutic modalities have been explored in small studies with design limitations that do not yet clearly provide direction for larger clinical trials that could support new clinical therapies. Given these gaps in our clinical, pathophysiologic, and therapeutic knowledge, we have identified priorities for future research including: the development of diagnostic criteria for limb dystonia, more precise phenotypic characterization and innovative clinical trial design that considers clinical heterogeneity, and limited available number of participants.
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Affiliation(s)
- Sarah Pirio Richardson
- Department of Neurology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Eckart Altenmüller
- Institute for Music Physiology and Musicians' Medicine (IMMM), Hannover University of Music, Drama and Media, Hannover, Germany
| | - Katharine Alter
- Functional and Applied Biomechanics Section, Rehabilitation Medicine, National Institute of Child Health and Development, National Institutes of Health, Bethesda, MD, USA
| | - Ron L Alterman
- Division of Neurosurgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Robert Chen
- Division of Neurology, Department of Medicine (Neurology), Krembil Research Institute, University of Toronto, Toronto, ON, Canada
| | - Steven Frucht
- Robert and John M. Bendheim Parkinson and Movement Disorders Center, Mount Sinai Hospital, New York, NY, USA
| | - Shinichi Furuya
- Musical Skill and Injury Center (MuSIC), Sophia University, Tokyo, Japan
| | - Joseph Jankovic
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - H A Jinnah
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Teresa J Kimberley
- Department of Rehabilitation Medicine, Division of Physical Therapy and Rehabilitation Science, University of Minnesota, Minneapolis, MN, USA
| | - Codrin Lungu
- Division of Clinical Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Joel S Perlmutter
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.,Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA.,Department of Neurosciences, Washington University School of Medicine, St. Louis, MO, USA.,Department of Physical Therapy, Washington University School of Medicine, St. Louis, MO, USA.,Department of Occupational Therapy, Washington University School of Medicine, St. Louis, MO, USA
| | - Cecília N Prudente
- Department of Rehabilitation Medicine, Division of Physical Therapy and Rehabilitation Science, University of Minnesota, Minneapolis, MN, USA
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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22
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Langbour N, Michel V, Dilharreguy B, Guehl D, Allard M, Burbaud P. The Cortical Processing of Sensorimotor Sequences is Disrupted in Writer's Cramp. Cereb Cortex 2017; 27:2544-2559. [PMID: 27114174 DOI: 10.1093/cercor/bhw108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Evidence for pre-existing abnormalities in the sensory and motor systems has been previously reported in writer's cramp (WC). However, the processing of somatosensory information during motor planning has received little attention. We hypothesized that sensorimotor integration processes might be impaired partly due to a disruption in the parieto-premotor network. To test this assumption, we designed 2 nonwriting motor tasks in which subjects had to perform a 4-finger motor sequence either on the basis of sensory stimuli previously memorized (SM task) or freely generated (SG task). Brain activity was measured by combining event-related functional magnetic resonance imaging and coherency electroencephalography in 15 WC patients and 15 normal controls. The bold signal was decreased in patients in both tasks during sensory stimulation but not during movement execution. However, the EEG study showed that coherency was decreased in patients compared with controls, during the delay of the SM task and during the execution of the SG task, on both the whole network and for specific couples of electrodes. Overall, these results demonstrate an endophenotypic impairment in the synchronization of cortical areas within the parieto-premotor network during somatosensory processing and motor planning in WC patients.
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Affiliation(s)
- N Langbour
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France
| | - V Michel
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.,Service de Neurophysiologie Clinique, Centre Hospitalier Universitaire de Bordeaux, 33076 Bordeaux, France
| | - B Dilharreguy
- Université de Bordeaux, INCIA, UMR 5287, F-33400 Talence, France.,CNRS, INCIA, UMR 5287, F-33400 Talence, France
| | - D Guehl
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.,Service de Neurophysiologie Clinique, Centre Hospitalier Universitaire de Bordeaux, 33076 Bordeaux, France
| | - M Allard
- Université de Bordeaux, INCIA, UMR 5287, F-33400 Talence, France.,CNRS, INCIA, UMR 5287, F-33400 Talence, France.,Service de Médecine Nucléaire, Centre Hospitalier Universitaire de Bordeaux, 33076 Bordeaux, France
| | - P Burbaud
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.,Service de Neurophysiologie Clinique, Centre Hospitalier Universitaire de Bordeaux, 33076 Bordeaux, France
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23
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Torres JAKL, Rosales RL. Nonmotor Symptoms in Dystonia. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2017; 134:1335-1371. [DOI: 10.1016/bs.irn.2017.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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24
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Impaired synaptic plasticity in RASopathies: a mini-review. J Neural Transm (Vienna) 2016; 123:1133-8. [PMID: 27565148 DOI: 10.1007/s00702-016-1609-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/16/2016] [Indexed: 12/21/2022]
Abstract
Synaptic plasticity in the form of long-term potentiation (LTP) and long-term depression (LTD) is considered to be the neurophysiological correlate of learning and memory. Impairments are discussed to be one of the underlying pathophysiological mechanisms of developmental disorders. In so-called RASopathies [e.g., neurofibromatosis 1 (NF1)], neurocognitive impairments are frequent and are affected by components of the RAS pathway which lead to impairments in synaptic plasticity. Transcranial magnetic stimulation (TMS) provides a non-invasive method to investigate synaptic plasticity in humans. Here, we review studies using TMS to evaluate synaptic plasticity in patients with RASopathies. Patients with NF1 and Noonan syndrome (NS) showed reduced cortical LTP-like synaptic plasticity. In contrast, increased LTP-like synaptic plasticity has been shown in Costello syndrome. Notably, lovastatin normalized impaired LTP-like plasticity and increased intracortical inhibition in patients with NF1. TMS has been shown to be a safe and efficient method to investigate synaptic plasticity and intracortical inhibition in patients with RASopathies. Deeper insights in impairments of synaptic plasticity in RASopathies could help to develop new options for the therapy of learning deficits in these patients.
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25
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Karabanov A, Ziemann U, Hamada M, George MS, Quartarone A, Classen J, Massimini M, Rothwell J, Siebner HR. Consensus Paper: Probing Homeostatic Plasticity of Human Cortex With Non-invasive Transcranial Brain Stimulation. Brain Stimul 2016; 8:993-1006. [PMID: 26598772 DOI: 10.1016/j.brs.2015.06.017] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Homeostatic plasticity is thought to stabilize neural activity around a set point within a physiologically reasonable dynamic range. Over the last ten years, a wide range of non-invasive transcranial brain stimulation (NTBS) techniques have been used to probe homeostatic control of cortical plasticity in the intact human brain. Here, we review different NTBS approaches to study homeostatic plasticity on a systems level and relate the findings to both, physiological evidence from in vitro studies and to a theoretical framework of homeostatic function. We highlight differences between homeostatic and other non-homeostatic forms of plasticity and we examine the contribution of sleep in restoring synaptic homeostasis. Finally, we discuss the growing number of studies showing that abnormal homeostatic plasticity may be associated to a range of neuropsychiatric diseases.
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26
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Suppa A, Huang YZ, Funke K, Ridding M, Cheeran B, Di Lazzaro V, Ziemann U, Rothwell J. Ten Years of Theta Burst Stimulation in Humans: Established Knowledge, Unknowns and Prospects. Brain Stimul 2016; 9:323-335. [DOI: 10.1016/j.brs.2016.01.006] [Citation(s) in RCA: 288] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/14/2016] [Accepted: 01/21/2016] [Indexed: 01/08/2023] Open
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27
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Chung SW, Hill AT, Rogasch NC, Hoy KE, Fitzgerald PB. Use of theta-burst stimulation in changing excitability of motor cortex: A systematic review and meta-analysis. Neurosci Biobehav Rev 2016; 63:43-64. [PMID: 26850210 DOI: 10.1016/j.neubiorev.2016.01.008] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/30/2015] [Accepted: 01/26/2016] [Indexed: 12/13/2022]
Abstract
Noninvasive brain stimulation has been demonstrated to modulate cortical activity in humans. In particular, theta burst stimulation (TBS) has gained notable attention due to its ability to induce lasting physiological changes after short stimulation durations. The present study aimed to provide a comprehensive meta-analytic review of the efficacy of two TBS paradigms; intermittent (iTBS) and continuous (cTBS), on corticospinal excitability in healthy individuals. Literature searches yielded a total of 87 studies adhering to the inclusion criteria. iTBS yielded moderately large MEP increases lasting up to 30 min with a pooled SMD of 0.71 (p<0.00001). cTBS produced a reduction in MEP amplitudes lasting up to 60 min, with the largest effect size seen at 5 min post stimulation (SMD=-0.9, P<0.00001). The collected studies were of heterogeneous nature, and a series of tests conducted indicated a degree of publication bias. No significant change in SICI and ICF was observed, with exception to decrease in SICI with cTBS at the early time point (SMD=0.42, P=0.00036). The results also highlight several factors contributing to TBS efficacy, including the number of pulses, frequency of stimulation and BDNF polymorphisms. Further research investigating optimal TBS stimulation parameters, particularly for iTBS, is needed in order for these paradigms to be successfully translated into clinical settings.
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Affiliation(s)
- Sung Wook Chung
- Monash Alfred Psychiatry Research Centre, Central Clinical School, The Alfred and Monash University, Melbourne, Australia.
| | - Aron T Hill
- Monash Alfred Psychiatry Research Centre, Central Clinical School, The Alfred and Monash University, Melbourne, Australia
| | - Nigel C Rogasch
- Brain and Mental Health Laboratory, School of Psychological Sciences and Monash Biomedical Imaging, Monash University, Melbourne, Australia
| | - Kate E Hoy
- Monash Alfred Psychiatry Research Centre, Central Clinical School, The Alfred and Monash University, Melbourne, Australia
| | - Paul B Fitzgerald
- Monash Alfred Psychiatry Research Centre, Central Clinical School, The Alfred and Monash University, Melbourne, Australia
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28
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Suppa A, Di Stasio F, Marsili L, Upadhyay N, Belvisi D, Conte A, Modugno N, Colosimo C, Berardelli A. Primary motor cortex LTP/LTD-like plasticity in probable corticobasal syndrome. J Neurophysiol 2016; 115:717-27. [DOI: 10.1152/jn.00755.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/10/2015] [Indexed: 11/22/2022] Open
Abstract
Whether the primary motor cortex (M1) contributes to the pathophysiology of corticobasal syndrome (CBS) remains unclear. In this study in patients with probable CBS, we tested whether M1 plasticity contributes to the pathophysiology of symptoms in the contralateral “less affected” limb, manifesting only parkinsonism, and in the contralateral “more affected” limb, manifesting parkinsonism plus other motor and nonmotor symptoms. In Experiment 1, we applied intermittent/continuous theta-burst stimulation (iTBS/cTBS) over the M1 contralateral to the less affected limb in 17 patients. In Experiment 2, we applied iTBS/cTBS over the M1 contralateral to the more affected limb in 14 of the 17 patients. We measured iTBS/cTBS-induced plasticity as reflected by motor-evoked potential (MEP) changes. Data were compared with those obtained in 17 healthy subjects (HS). In Experiment 1, TBS over the M1 contralateral to the less affected limb disclosed reduced plasticity in patients than in HS. In Experiment 2, in 5 of 14 patients we recorded abnormally low-amplitude MEPs, preventing the evaluation of plasticity in the M1 contralateral to the more affected limb. In the remaining nine patients, TBS disclosed abnormal plasticity characterized by high intersubject variability. In these nine patients, the response to TBS correlated with specific patients' clinical features. In the present study in patients with probable CBS, we have demonstrated heterogeneous abnormalities of M1 that contribute to the pathophysiology of this condition.
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Affiliation(s)
- Antonio Suppa
- Department of Neurology and Psychiatry, “Sapienza” University of Rome, Rome, Italy; and
- Neuromed Institute, “Sapienza” University of Rome, Rome, Italy
| | | | - Luca Marsili
- Department of Neurology and Psychiatry, “Sapienza” University of Rome, Rome, Italy; and
| | - Neeraj Upadhyay
- Department of Neurology and Psychiatry, “Sapienza” University of Rome, Rome, Italy; and
| | - Daniele Belvisi
- Department of Neurology and Psychiatry, “Sapienza” University of Rome, Rome, Italy; and
- Neuromed Institute, “Sapienza” University of Rome, Rome, Italy
| | - Antonella Conte
- Department of Neurology and Psychiatry, “Sapienza” University of Rome, Rome, Italy; and
- Neuromed Institute, “Sapienza” University of Rome, Rome, Italy
| | - Nicola Modugno
- Neuromed Institute, “Sapienza” University of Rome, Rome, Italy
| | - Carlo Colosimo
- Department of Neurology and Psychiatry, “Sapienza” University of Rome, Rome, Italy; and
| | - Alfredo Berardelli
- Department of Neurology and Psychiatry, “Sapienza” University of Rome, Rome, Italy; and
- Neuromed Institute, “Sapienza” University of Rome, Rome, Italy
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29
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Dileone M, Ranieri F, Florio L, Capone F, Musumeci G, Leoni C, Mordillo-Mateos L, Tartaglia M, Zampino G, Di Lazzaro V. Differential Effects of HRAS Mutation on LTP-Like Activity Induced by Different Protocols of Repetitive Transcranial Magnetic Stimulation. Brain Stimul 2016; 9:33-8. [DOI: 10.1016/j.brs.2015.08.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 08/21/2015] [Accepted: 08/24/2015] [Indexed: 11/30/2022] Open
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Wischnewski M, Schutter DJ. Efficacy and time course of paired associative stimulation in cortical plasticity: Implications for neuropsychiatry. Clin Neurophysiol 2016; 127:732-739. [DOI: 10.1016/j.clinph.2015.04.072] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/16/2015] [Accepted: 04/24/2015] [Indexed: 12/20/2022]
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Non-motor symptoms in patients with adult-onset focal dystonia: Sensory and psychiatric disturbances. Parkinsonism Relat Disord 2016; 22 Suppl 1:S111-4. [DOI: 10.1016/j.parkreldis.2015.09.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 11/29/2022]
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Kimberley TJ, Schmidt RLS, Chen M, Dykstra DD, Buetefisch CM. Mixed effectiveness of rTMS and retraining in the treatment of focal hand dystonia. Front Hum Neurosci 2015. [PMID: 26217209 PMCID: PMC4496570 DOI: 10.3389/fnhum.2015.00385] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Though the pathophysiology of dystonia remains uncertain, two primary factors implicated in the development of dystonic symptoms are excessive cortical excitability and impaired sensorimotor processing. The aim of this study was to determine the functional efficacy of an intervention combining repetitive transcranial magnetic stimulation (rTMS) and sensorimotor retraining. A randomized, single-subject, multiple baseline design with crossover was used to examine participants with focal hand dystonia (FHD) (n = 9). Intervention: 5 days rTMS + sensorimotor retraining (SMR) vs. Five days rTMS + control therapy (CTL) (which included stretching and massage). The rTMS was applied to the premotor cortex at 1 Hz at 80% resting motor threshold for 1200 pulses. For sensorimotor retraining, a subset of the Learning-based Sensorimotor Training program was followed. Each session in both groups consisted of rTMS followed immediately by 30 min of the therapy intervention (SMR or CTL). Contrary to our hypothesis, group analyses revealed no additional benefit from the SMR training vs. CTL. When analyzed across group however, there was significant improvement from the first baseline assessment in several measures, including tests of sensory ability and self-rated changes. The patient rated improvements were accompanied by a moderate effect size suggesting clinical meaningfulness. These results provide encouragement for further investigation of rTMS in FHD with a need to optimize a secondary intervention and determine likely responders vs. non-responders.
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Affiliation(s)
- Teresa J Kimberley
- Program in Physical Therapy, Brain Plasticity Laboratory, Department of Physical Medicine and Rehabilitation, University of Minnesota Minneapolis, MN, USA
| | - Rebekah L S Schmidt
- Program in Physical Therapy, Brain Plasticity Laboratory, Department of Physical Medicine and Rehabilitation, University of Minnesota Minneapolis, MN, USA
| | - Mo Chen
- Program in Physical Therapy, Brain Plasticity Laboratory, Department of Physical Medicine and Rehabilitation, University of Minnesota Minneapolis, MN, USA
| | - Dennis D Dykstra
- Department of Physical Medicine and Rehabilitation, University of Minnesota Minneapolis, MN, USA
| | - Cathrin M Buetefisch
- Department of Neurology and Rehabilitation Medicine, Emory University Atlanta, GA, USA
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33
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Wischnewski M, Schutter DJLG. Efficacy and Time Course of Theta Burst Stimulation in Healthy Humans. Brain Stimul 2015; 8:685-92. [PMID: 26014214 DOI: 10.1016/j.brs.2015.03.004] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/12/2015] [Accepted: 03/20/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND In the past decade research has shown that continuous (cTBS) and intermittent theta burst stimulation (iTBS) alter neuronal excitability levels in the primary motor cortex. OBJECTIVE Quantitatively review the magnitude and time course on cortical excitability of cTBS and iTBS. METHODS Sixty-four TBS studies published between January 2005 and October 2014 were retrieved from the scientific search engine PubMED and included for analyses. The main inclusion criteria involved stimulation of the primary motor cortex in healthy volunteers with no motor practice prior to intervention and motor evoked potentials as primary outcome measure. RESULTS ITBS applied for 190 s significantly increases cortical excitability up to 60 min with a mean maximum potentiation of 35.54 ± 3.32%. CTBS applied for 40 s decreases cortical excitability up to 50 min with a mean maximum depression of -22.81 ± 2.86%, while cTBS applied for 20 s decreases cortical excitability (mean maximum -27.84 ± 4.15%) for 20 min. CONCLUSION The present findings offer normative insights into the magnitude and time course of TBS-induced changes in cortical excitability levels.
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Affiliation(s)
- Miles Wischnewski
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, the Netherlands.
| | - Dennis J L G Schutter
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, the Netherlands
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Belvisi D, Kassavetis P, Bologna M, Edwards MJ, Berardelli A, Rothwell JC. Associative plasticity in surround inhibition circuits in human motor cortex. Eur J Neurosci 2014; 40:3704-10. [PMID: 25288190 DOI: 10.1111/ejn.12738] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 08/20/2014] [Accepted: 09/01/2014] [Indexed: 11/29/2022]
Abstract
Surround inhibition is a physiological mechanism that is hypothesised to improve contrast between signals in the central nervous system. In the human motor system, motor surround inhibition (mSI) can be assessed using transcranial magnetic stimulation (TMS). We evaluated whether it is possible to modulate mSI, using a paradigm able to induce plastic effects in primary motor cortex (M1). Fifteen healthy volunteers participated in the experiments. To assess mSI, we delivered single pulses at rest and at the onset of a right thumb abduction. TMS pulses over abductor digiti minimi (ADM; surround muscle) hotspot were delivered when EMG activity in right abductor pollicis brevis (APB; active muscle) > 100 μV was detected. Paired associative stimulation (PAS) was delivered using peripheral median nerve electric stimulation and TMS over APB M1 area at an interstimulus interval of 21.5 ms for the real PAS (PAS21.5) and 100 ms for the sham PAS (PAS100). To verify the effect of PAS21.5 on mSI we collected 20 MEPs from ADM at rest and during APB movements before (T0) and 5 (T1), 15 (T2) and 30 (T3) minutes after PAS21.5. mSI from APB to ADM was present at baseline. PAS21.5 increased the amount of mSI compared with baseline whereas there was no effect after PAS100. Our results suggest that mSI is an adaptable phenomenon depending on prior experience.
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Affiliation(s)
- Daniele Belvisi
- Neuromed Institute IRCCS, Via Atinense 18, 86077, Pozzilli, IS, Italy
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35
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Vallence AM, Ridding MC. Non-invasive induction of plasticity in the human cortex: Uses and limitations. Cortex 2014; 58:261-71. [DOI: 10.1016/j.cortex.2013.12.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/01/2013] [Accepted: 12/16/2013] [Indexed: 10/25/2022]
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36
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Koch G, Porcacchia P, Ponzo V, Carrillo F, Cáceres-Redondo MT, Brusa L, Desiato MT, Arciprete F, Di Lorenzo F, Pisani A, Caltagirone C, Palomar FJ, Mir P. Effects of Two Weeks of Cerebellar Theta Burst Stimulation in Cervical Dystonia Patients. Brain Stimul 2014; 7:564-72. [DOI: 10.1016/j.brs.2014.05.002] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 04/27/2014] [Accepted: 05/01/2014] [Indexed: 10/25/2022] Open
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37
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Primary somatosensory cortical plasticity and tactile temporal discrimination in focal hand dystonia. Clin Neurophysiol 2014; 125:537-43. [DOI: 10.1016/j.clinph.2013.08.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 07/31/2013] [Accepted: 08/14/2013] [Indexed: 11/24/2022]
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38
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Quartarone A, Hallett M. Emerging concepts in the physiological basis of dystonia. Mov Disord 2014; 28:958-67. [PMID: 23893452 DOI: 10.1002/mds.25532] [Citation(s) in RCA: 288] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 04/30/2013] [Accepted: 05/02/2013] [Indexed: 12/31/2022] Open
Abstract
Work over the past 2 decades has led to substantial changes in our understanding of dystonia pathophysiology. Three general abnormalities appear to underlie the pathophysiological substrate. The first is a loss of inhibition. This makes sense considering that it may be responsible for the excess of movement and for the overflow phenomena seen in dystonia. A second abnormality is sensory dysfunction which is related to the mild sensory complaints in patients with focal dystonias and may be responsible for some of the motor dysfunction. Third, evidence from animal models of dystonia as well as from patients with primary dystonia has revealed significant alterations of synaptic plasticity characterized by a disruption of homeostatic plasticity, with a prevailing facilitation of synaptic potentiation, together with the loss of synaptic inhibitory processes. We speculate that during motor learning this abnormal plasticity may lead to an abnormal sensorimotor integration, leading to consolidation of abnormal motor engrams. If so, then removing this abnormal plasticity might have little immediate effect on dystonic movements because bad motor memories have already been ''learned'' and are difficult to erase. These considerations might explain the delayed clinical effects of deep brain stimulation (DBS) in patients with generalized dystonia. Current lines of research will be discussed from a network perspective. © 2013 Movement Disorder Society.
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Affiliation(s)
- Angelo Quartarone
- Department of Neurosciences, Psychiatry, and Anaesthesiological Science, University of Messina, Messina, Italy.
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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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40
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Hubsch C, Roze E, Popa T, Russo M, Balachandran A, Pradeep S, Mueller F, Brochard V, Quartarone A, Degos B, Vidailhet M, Kishore A, Meunier S. Defective cerebellar control of cortical plasticity in writer's cramp. ACTA ACUST UNITED AC 2013; 136:2050-62. [PMID: 23801734 DOI: 10.1093/brain/awt147] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
A large body of evidence points to a role of basal ganglia dysfunction in the pathophysiology of dystonia, but recent studies indicate that cerebellar dysfunction may also be involved. The cerebellum influences sensorimotor adaptation by modulating sensorimotor plasticity of the primary motor cortex. Motor cortex sensorimotor plasticity is maladaptive in patients with writer's cramp. Here we examined whether putative cerebellar dysfunction in dystonia is linked to these patients' maladaptive plasticity. To that end we compared the performances of patients and healthy control subjects in a reaching task involving a visuomotor conflict generated by imposing a random deviation (-40° to 40°) on the direction of movement of the mouse/cursor. Such a task is known to involve the cerebellum. We also compared, between patients and healthy control subjects, how the cerebellum modulates the extent and duration of an ongoing sensorimotor plasticity in the motor cortex. The cerebellar cortex was excited or inhibited by means of repeated transcranial magnetic stimulation before artificial sensorimotor plasticity was induced in the motor cortex by paired associative stimulation. Patients with writer's cramp were slower than the healthy control subjects to reach the target and, after having repeatedly adapted their trajectories to the deviations, they were less efficient than the healthy control subjects to perform reaching movement without imposed deviation. It was interpreted as impaired washing-out abilities. In healthy subjects, cerebellar cortex excitation prevented the paired associative stimulation to induce a sensorimotor plasticity in the primary motor cortex, whereas cerebellar cortex inhibition led the paired associative stimulation to be more efficient in inducing the plasticity. In patients with writer's cramp, cerebellar cortex excitation and inhibition were both ineffective in modulating sensorimotor plasticity. In patients with writer's cramp, but not in healthy subjects, behavioural parameters reflecting their capacity for adapting to the rotation and for washing-out of an earlier adaptation predicted the efficacy of inhibitory cerebellar conditioning to influence sensorimotor plasticity: the better the online adaptation, the smaller the influence of cerebellar inhibitory stimulation on motor cortex plasticity. Altered cerebellar encoding of incoming afferent volleys may result in decoupling the motor component from the afferent information flow, and also in maladjusted sensorimotor calibration. The loss of cerebellar control over sensorimotor plasticity might also lead to building up an incorrect motor program to specific adaptation tasks such as writing.
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Affiliation(s)
- Cecile Hubsch
- Department of Neurology, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
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Abstract
AbstractPrimary isolated dystonia is a hyperkinetic movement disorder whereby involuntary muscle contractions cause twisted and abnormal postures. Dystonia of the cervical spine and upper limb may present as sustained muscle contractions or task-specific activity when using the hand or upper limb. There is little understanding of the pathophysiology underlying dystonia and this presents a challenge for clinicians and researchers alike. Emerging evidence that the cerebellum is involved in the pathophysiology of dystonia using network models presents the intriguing concept that the cerebellum could provide a novel target for non-invasive brain stimulation. Non-invasive stimulation to increase cerebellar excitability improved aspects of handwriting and circle drawing in a small cohort of people with focal hand and cervical dystonia. Mechanisms underlying the improvement in function are unknown, but putative pathways may involve the red nucleus and/or the cervical propriospinal system. Furthermore, recent understanding that the cerebellum has both motor and cognitive functions suggests that non-invasive cerebellar stimulation may improve both motor and non-motor aspects of dystonia. We propose a combination of motor and non-motor tasks that challenge cerebellar function may be combined with cerebellar non-invasive brain stimulation in the treatment of focal dystonia. Better understanding of how the cerebellum contributes to dystonia may be gained by using network models such as our putative circuits involving red nucleus and/or the cervical propriospinal system. Finally, novel treatment interventions encompassing both motor and non-motor functions of the cerebellum may prove effective for neurological disorders that exhibit cerebellar dysfunction.
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