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Deuschl G, Becktepe JS, Dirkx M, Haubenberger D, Hassan A, Helmich R, Muthuraman M, Panyakaew P, Schwingenschuh P, Zeuner KE, Elble RJ. The clinical and electrophysiological investigation of tremor. Clin Neurophysiol 2022; 136:93-129. [DOI: 10.1016/j.clinph.2022.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/05/2022] [Accepted: 01/07/2022] [Indexed: 01/18/2023]
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Elble RJ. Bayesian Interpretation of Essential Tremor Plus. J Clin Neurol 2022; 18:127-139. [PMID: 35274833 PMCID: PMC8926770 DOI: 10.3988/jcn.2022.18.2.127] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 11/21/2022] Open
Abstract
Essential tremor (ET) plus is a new tremor classification that was introduced in 2018 by a task force of the International Parkinson and Movement Disorder Society. Patients with ET plus meet the criteria for ET but have one or more additional systemic or neurologic signs of uncertain significance or relevance to tremor (“soft signs”). Soft signs are not sufficient to diagnose another tremor syndrome or movement disorder, and soft signs in ET plus are known to have poor interrater reliability and low diagnostic sensitivity and specificity. Therefore, the clinical significance of ET plus must be interpreted probabilistically when judging whether a patient is more likely to have ET or a combined tremor syndrome, such as dystonic tremor. Such a probabilistic interpretation is possible with Bayesian analysis. This review presents a Bayesian analysis of ET plus in patients suspected of having ET versus a dystonic tremor syndrome, which is the most common differential diagnosis in patients referred for ET. Bayesian analysis of soft signs provides an estimate of the probability that a patient with possible ET is more likely to have an alternative diagnosis. ET plus is a distinct tremor classification and should not be viewed as a subtype of ET. ET plus covers a more-comprehensive phenotyping of people with possible ET, and the clinical interpretation of ET plus is enhanced with Bayesian analysis of associated soft signs.
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Affiliation(s)
- Rodger J. Elble
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, IL, USA
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Abstract
Tremor is the most commonly encountered movement disorder in clinical practice. A wide range of pathologies may manifest with tremor either as a presenting or predominant symptom. Considering the marked etiological and phenomenological heterogeneity, it would be desirable to develop a classification of tremors that reflects their underlying pathophysiology. The tremor task force of the International Parkinson Disease and Movement Disorders Society has worked toward this goal and proposed a new classification system. This system has remained a prime topic of scientific communications on tremor in recent times. The new classification is based on two axes: 1. based on the clinical features, history, and tremor characteristics and 2. based on the etiology of tremor. In this article, we discuss the key aspects of the new classification, review various tremor syndromes, highlight some of the controversies in the field of tremor, and share the potential future perspectives.
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Affiliation(s)
- Abhishek Lenka
- Department of Neurology, Medstar Georgetown University Hospital, Washington, DC, United States
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, United States
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Latorre A, Rocchi L, Batla A, Berardelli A, Rothwell JC, Bhatia KP. The Signature of Primary Writing Tremor Is Dystonic. Mov Disord 2021; 36:1715-1720. [PMID: 33786886 DOI: 10.1002/mds.28579] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND It has been debated for decades whether primary writing tremor is a form of dystonic tremor, a variant of essential tremor, or a separate entity. We wished to test the hypothesis that primary writing tremor and dystonia share a common pathophysiology. OBJECTIVES The objective of the present study was to investigate the pathophysiological hallmarks of dystonia in patients affected by primary writing tremor. METHODS Ten patients with idiopathic dystonic tremor syndrome, 7 with primary writing tremor, 10 with essential tremor, and 10 healthy subjects were recruited. They underwent eyeblink classic conditioning, blink recovery cycle, and transcranial magnetic stimulation assessment, including motor-evoked potentials and short- and long-interval intracortical inhibition at baseline. Transcranial magnetic stimulation measures were also recorded after paired-associative plasticity protocol. RESULTS Primary writing tremor and dystonic tremor syndrome had a similar pattern of electrophysiological abnormalities, consisting of reduced eyeblink classic conditioning learning, reduced blink recovery cycle inhibition, and a lack of effect of paired-associative plasticity on long-interval intracortical inhibition. The latter 2 differ from those obtained in essential tremor and healthy subjects. Although not significant, slightly reduced short-interval intracortical inhibition and a larger effect of paired-associative plasticity in primary writing tremor and dystonic tremor syndrome, compared with essential tremor and healthy subjects, was observed. CONCLUSIONS Our initial hypothesis of a common pathophysiology between dystonia and primary writing tremor has been confirmed. Primary writing tremor might be considered a form of dystonic tremor. © 2021 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK.,Department of Human Neurosciences, University of Rome "Sapienza,", Rome, Italy
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK.,Department of Medical Sciences and Public Health, University of Cagliari, 09124, Cagliari, Italy
| | - Amit Batla
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK
| | - Alfredo Berardelli
- Department of Human Neurosciences, University of Rome "Sapienza,", Rome, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Pozzilli, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology University College London, London, UK
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Murgai AA, Jog M. Focal limb dystonia and tremor: Clinical update. Toxicon 2020; 176:10-14. [PMID: 31965968 DOI: 10.1016/j.toxicon.2020.01.004] [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: 08/24/2019] [Revised: 01/04/2020] [Accepted: 01/13/2020] [Indexed: 10/25/2022]
Abstract
The association between tremor and dystonia has been known for many decades. Dystonic tremor is seen in the body part affected with dystonia. Tremor and dystonia can also co-exist in different body parts. Subtle dystonic posturing can be missed in patients with upper limb tremor and these patients are often misdiagnosed as essential tremor. Careful clinical examination and electrophysiology may help in differentiating classical essential tremor from dystonic tremor. Writer's cramp, a common focal hand dystonia can mimic primary writing tremor when the dystonic posturing is subtle. Oral medications have limited therapeutic efficacy. Botulinum toxin is considered as first line therapy for focal limb dystonia and is also effective in the treatment of tremor. Surgical options are reserved for cases refractory to medical therapy. In this review, we summarize the current state of knowledge of focal limb dystonia and tremor with a focus on underlying neurophysiology in these conditions.
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Affiliation(s)
- Aditya Ashok Murgai
- Department of Clinical Neurological Sciences, Western University, London, Canada
| | - Mandar Jog
- Department of Clinical Neurological Sciences, Western University, London, Canada.
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Bourdens M, Aupy J, Ribot B, Burbaud P, Guehl D. Dystonic writing tremor. Rev Neurol (Paris) 2019; 175:203-205. [DOI: 10.1016/j.neurol.2018.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/18/2018] [Accepted: 04/24/2018] [Indexed: 11/15/2022]
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Lenka A, Jhunjhunwala KR, Panda R, Saini J, Bharath RD, Yadav R, Pal PK. Altered brain network measures in patients with primary writing tremor. Neuroradiology 2017; 59:1021-1029. [PMID: 28779337 DOI: 10.1007/s00234-017-1895-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Accepted: 07/26/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE Primary writing tremor (PWT) is a rare task-specific tremor, which occurs only while writing or while adopting the hand in the writing position. The basic pathophysiology of PWT has not been fully understood. The objective of this study is to explore the alterations in the resting state functional brain connectivity, if any, in patients with PWT using graph theory-based analysis. METHODS This prospective case-control study included 10 patients with PWT and 10 age and gender matched healthy controls. All subjects underwent MRI in a 3-Tesla scanner. Several parameters of small-world functional connectivity were compared between patients and healthy controls by using graph theory-based analysis. RESULTS There were no significant differences in age, handedness (all right handed), gender distribution (all were males), and MMSE scores between the patients and controls. The mean age at presentation of tremor in the patient group was 51.7 ± 8.6 years, and the mean duration of tremor was 3.5 ± 1.9 years. Graph theory-based analysis revealed that patients with PWT had significantly lower clustering coefficient and higher path length compared to healthy controls suggesting alterations in small-world architecture of the brain. The clustering coefficients were lower in PWT patients in left and right medial cerebellum, right dorsolateral prefrontal cortex (DLPFC), and left posterior parietal cortex (PPC). CONCLUSION Patients with PWT have significantly altered small-world brain connectivity in bilateral medial cerebellum, right DLPFC, and left PPC. Further studies with larger sample size are required to confirm our results.
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Affiliation(s)
- Abhishek Lenka
- Department of Clinical Neurosciences, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, Karnataka, 560029, India.,Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, Karnataka, 560029, India
| | - Ketan Ramakant Jhunjhunwala
- Department of Clinical Neurosciences, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, Karnataka, 560029, India.,Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, Karnataka, 560029, India
| | - Rajanikant Panda
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, Karnataka, 560029, India
| | - Jitender Saini
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, Karnataka, 560029, India
| | - Rose Dawn Bharath
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, Karnataka, 560029, India
| | - Ravi Yadav
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, Karnataka, 560029, India
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, Karnataka, 560029, India.
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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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Deep brain stimulation for dystonia: a novel perspective on the value of genetic testing. J Neural Transm (Vienna) 2017; 124:417-430. [PMID: 28160152 DOI: 10.1007/s00702-016-1656-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/16/2016] [Indexed: 10/20/2022]
Abstract
The dystonias are a group of disorders characterized by excessive muscle contractions leading to abnormal movements and postures. There are many different clinical manifestations and underlying causes. Deep brain stimulation (DBS) provides an effect treatment, but outcomes can vary considerably among the different subtypes of dystonia. Several variables are thought to contribute to this variation including age of onset and duration of dystonia, specific characteristics of the dystonic movements, location of stimulation and stimulator settings, and others. The potential contributions of genetic factors have received little attention. In this review, we summarize evidence that some of the variation in DBS outcomes for dystonia is due to genetic factors. The evidence suggests that more methodical genetic testing may provide useful information in the assessment of potential surgical candidates, and in advancing our understanding of the biological mechanisms that influence DBS outcomes.
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Abstract
PURPOSE OF REVIEW Essential tremor has not been defined or used consistently in clinical diagnosis and research. Other monosymptomatic disorders are often referred to as essential tremor variants. RECENT FINDINGS There is now solid evidence that essential tremor, however defined, is a syndrome with multiple causes. SUMMARY A new tremor classification scheme is being developed by the International Parkinson and Movement Disorder Society Task Force on Tremor. In this scheme, tremor in the absence of other neurological signs is called isolated tremor, and tremor in combination with other signs is called combined tremor. Many isolated and combined tremor syndromes can be defined on the basis of commonly recurring or unique clinical symptoms and signs, including historical features (age at onset, family history, and temporal evolution) and tremor characteristics (body distribution, activation condition, associated features). Essential tremor, however defined, is simply a syndrome and not a specific disease. Essential tremor should be defined and used consistently, or this term should be abandoned. As essential tremor is an arbitrarily defined syndrome, it makes no sense to refer to other tremors as variants of essential tremor or essential tremor syndromes.
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Ramirez-Zamora A, Kaszuba B, Gee L, Prusik J, Molho E, Wilock M, Shin D, Pilitsis JG. Clinical outcome and intraoperative neurophysiology for focal limb dystonic tremor without generalized dystonia treated with deep brain stimulation. Clin Neurol Neurosurg 2016; 150:169-176. [DOI: 10.1016/j.clineuro.2016.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/03/2016] [Accepted: 06/05/2016] [Indexed: 01/14/2023]
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Erro R, Ciocca M, Hirschbichler ST, Rothwell JC, Bhatia KP. Primary writing tremor is a dystonic trait: Evidence from an instructive family. J Neurol Sci 2015; 356:210-1. [DOI: 10.1016/j.jns.2015.06.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 06/18/2015] [Accepted: 06/22/2015] [Indexed: 11/24/2022]
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Schreglmann SR, Baumann CR, Waldvogel D. Mirror Writing Tremor: Dystonic Clues…. Mov Disord Clin Pract 2015; 2:316-317. [PMID: 30363557 DOI: 10.1002/mdc3.12182] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 03/05/2015] [Accepted: 03/11/2015] [Indexed: 11/06/2022] Open
Affiliation(s)
- Sebastian R Schreglmann
- Department of Neurology University Hospital Zurich Zurich Switzerland.,Department of Neurology Kantonsspital St. Gallen St. Gallen Switzerland
| | | | - Daniel Waldvogel
- Department of Neurology University Hospital Zurich Zurich Switzerland
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Dystonia as a network disorder: what is the role of the cerebellum? Neuroscience 2013; 260:23-35. [PMID: 24333801 DOI: 10.1016/j.neuroscience.2013.11.062] [Citation(s) in RCA: 188] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 11/20/2013] [Accepted: 11/20/2013] [Indexed: 01/02/2023]
Abstract
The dystonias are a group of disorders defined by sustained or intermittent muscle contractions that result in involuntary posturing or repetitive movements. There are many different clinical manifestations and causes. Although they traditionally have been ascribed to dysfunction of the basal ganglia, recent evidence has suggested dysfunction may originate from other regions, particularly the cerebellum. This recent evidence has led to an emerging view that dystonia is a network disorder that involves multiple brain regions. The new network model for the pathogenesis of dystonia has raised many questions, particularly regarding the role of the cerebellum. For example, if dystonia may arise from cerebellar dysfunction, then why are there no cerebellar signs in dystonia? Why are focal cerebellar lesions or degenerative cerebellar disorders more commonly associated with ataxia rather than dystonia? Why is dystonia more commonly associated with basal ganglia lesions rather than cerebellar lesions? Can answers obtained from animals be extrapolated to humans? Is there any evidence that the cerebellum is not involved? Finally, what is the practical value of this new model of pathogenesis for the neuroscientist and clinician? This article explores potential answers to these questions.
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