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Experimental Brain Research Aug 2020Studying plasticity mechanisms with Professor John Rothwell was a shared highlight of our careers. In this article, we discuss non-invasive brain stimulation techniques... (Review)
Review
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.
Topics: Dystonia; Dystonic Disorders; Humans; Neuronal Plasticity
PubMed: 32206849
DOI: 10.1007/s00221-020-05773-3 -
Tremor and Other Hyperkinetic Movements... Feb 2021Reports of drummers' dystonia are rare, particularly compared to the literature on dystonia in string, piano and brass players. Several cases of drummers' dystonia have...
BACKGROUND
Reports of drummers' dystonia are rare, particularly compared to the literature on dystonia in string, piano and brass players. Several cases of drummers' dystonia have been included in large series of multiple instrumentalists, but there are few reports comprised exclusively of drummers with musicians' dystonia. We present here a series of 12 drummers with task-specific, focal dystonia affecting their upper limbs while drumming and spanning multiple playing techniques and musical styles.
METHODS
We conducted a retrospective chart review of drummers with dystonia seen at academic Movement Disorders centers.
RESULTS
All 12 patients were male, and the majority eventually developed spread of dystonia to tasks other than drumming. Ten of the 12 had dystonia affecting their fingers, while 8/12 had dystonia affecting the wrist. Only 1/12 had involvement proximal to the wrist. Pharmacologic interventions were largely ineffective; 3 had some benefit from botulinum toxin injections, but this was limited by problematic weakness in one drummer.
DISCUSSION
The phenomenology in our series is concordant with prior reported cases, demonstrating frequent wrist involvement, though we also found that a greater proportion of patients had dystonia affecting the fingers. It could be hypothesized that different drumming techniques or musical styles modulate the relative risk of dystonic involvement of the different anatomical regions of the upper limb.
HIGHLIGHTS
Drummers' dystonia is one of the least common forms of musicians' dystonia, though this may reflect fewer numbers of these instrumentalists. We present the largest series of drummers' dystonia and review previously published cases. Our cohort, representing diverse drumming styles, showed frequent involvement of dystonia in the wrists and fingers.
Topics: Dystonia; Dystonic Disorders; Female; Humans; Male; Music; Retrospective Studies
PubMed: 33633869
DOI: 10.5334/tohm.577 -
European Journal of Paediatric... Jan 2017Heterogeneous by the underlying pathobiology and clinical presentation, childhood onset dystonia is most frequently progressive, with related disability and limitations... (Comparative Study)
Comparative Study Review
BACKGROUND
Heterogeneous by the underlying pathobiology and clinical presentation, childhood onset dystonia is most frequently progressive, with related disability and limitations in functions of daily living. Consequently, there is an obvious need for efficient symptomatic therapies.
METHODS AND RESULTS
Following lesional surgery to basal ganglia (BG) and thalamus, deep brain stimulation (DBS) is a more conservative and adjustable intervention to and validated for internal segment of the globus pallidus (GPi), highly efficient in treating isolated "primary" dystonia and associated symptoms such as subcortical myoclonus. The role of DBS in acquired, neurometabolic and degenerative disorders with dystonia deserves further exploration to confirm as an efficient and lasting therapy. However, the pathobiological background with distribution of the sequellae over the central nervous system and related clinical features, will limit DBS efficacy in these conditions. Cumulative arguments propose DBS in severe life threatening dystonic conditions called status dystonicus as first line therapy, irrespective of the underlying cause. There are no currently available validated selection criteria for DBS in pediatric dystonia. Concurrent targets such as subthalamic nucleus (STN) and several motor nuclei of the thalamus are under exploration and only little information is available in children. DBS programming in paediatric population was adopted from experience in adults. The choice of neuromodulatory DBS parameters could influence not only the initial therapeutic outcome of dystonic symptoms but also its maintenance over time and potentially the occurrence of DBS related side effects.
CONCLUSION
DBS allows efficient symptomatic treatment of severe dystonia in children and advances pathophysiological knowledge about local and distributed abnormal neural activity over the motor cortical-subcortical networks in dystonia and other movement disorders.
Topics: Adult; Child; Deafness; Deep Brain Stimulation; Dystonia; Dystonic Disorders; Female; Globus Pallidus; Humans; Male; Patient Selection; Subthalamic Nucleus; Thalamus; Treatment Outcome
PubMed: 27693334
DOI: 10.1016/j.ejpn.2016.08.010 -
Current Opinion in Neurology Aug 2023The aim of this review is to showcase the recent developments in the field of diagnosis and treatment of adult-onset focal dystonia. (Review)
Review
PURPOSE OF REVIEW
The aim of this review is to showcase the recent developments in the field of diagnosis and treatment of adult-onset focal dystonia.
RECENT FINDINGS
Accurate phenotyping of focal dystonia is essential in the process of finding an underlying cause, including acquired, genetic, and idiopathic causes. Motor symptoms as well as the associated nonmotor symptoms and their detrimental impact on quality of life have received increased interest over the last years. The diagnostic process is complicated by the steadily increasing numbers of newly discovered genes associated with dystonia. Recent efforts have been aimed at further developing recommendations and algorithms to aid in diagnosis and in navigating the use of diagnostic tools. In terms of treatment, research on DBS is advancing towards a better understanding of the most effective stimulation locations within the globus pallidus. Moreover, with the introduction of the LFP-recording devices, the search continues for an accurate electrophysiological biomarker for dystonia.
SUMMARY
Accurate phenotyping and (sub)classification of patients with dystonia is important for improving diagnosis, subsequent treatment effect and population-based study outcomes in research. Medical practitioners should be attentive to the presence of nonmotor symptoms in dystonia.
Topics: Humans; Adult; Dystonia; Quality of Life; Deep Brain Stimulation; Treatment Outcome; Dystonic Disorders; Globus Pallidus
PubMed: 37381892
DOI: 10.1097/WCO.0000000000001165 -
Toxins Dec 2017Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and... (Review)
Review
Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this article, we discuss approaches to selecting upper and lower extremity muscles for chemodenervation treatment of limb dystonia.
Topics: Botulinum Toxins; Dystonia; Dystonic Disorders; Humans; Muscles
PubMed: 29286305
DOI: 10.3390/toxins10010020 -
Arquivos de Neuro-psiquiatria Nov 2016The diagnosis and treatment of dystonia are challenging. This is likely due to gaps in the complete understanding of its pathophysiology, lack of animal models for... (Review)
Review
The diagnosis and treatment of dystonia are challenging. This is likely due to gaps in the complete understanding of its pathophysiology, lack of animal models for translational studies, absence of a consistent pathological substrate and highly variable phenotypes and genotypes. The aim of this review article is to provide an overview of the clinical, neurophysiological and genetic features of dystonia that can help in the identification of this movement disorder, as well as in the differential diagnosis of the main forms of genetic dystonia. The variation of penetrance, age of onset, and topographic distribution of the disease in carriers of the same genetic mutation indicates that other factors - either genetic or environmental - might be involved in the development of symptoms. The growing knowledge of cell dysfunction in mutants may give insights into more effective therapeutic targets.
Topics: Algorithms; Diagnosis, Differential; Dystonia; Dystonic Disorders; Humans; Protein Interaction Maps; Risk Factors; Tremor
PubMed: 27901258
DOI: 10.1590/0004-282X20160140 -
Brain and Behavior Feb 2022Japanese encephalitis (JE) is a potentially fatal viral infection with a wide range of manifestations and can also present with a variety of movement disorders (MD)... (Review)
Review
BACKGROUND
Japanese encephalitis (JE) is a potentially fatal viral infection with a wide range of manifestations and can also present with a variety of movement disorders (MD) including dystonia. Dystonic features in JE are uncommon. Here, we have tried to summarize the clinical features and management of dystonia among JE patients with a comprehensive literature search.
METHODS
Various databases, including PubMed, Embase, and Google Scholar, were searched against the predefined criteria using suitable keywords combination and boolean operations. Relevant information from observational and case studies was extracted according to the author, dystonic features, radiological changes in the brain scans, treatment options, and outcome wherever provided.
RESULT
We identified 19 studies with a total of 1547 JE patients, the diagnosis of which was confirmed by IgM detection in serum and/or cerebrospinal fluid in the majority of the patients (88.62%). 234 (15.13%) of JE patients had dystonia with several types of focal dystonia being present in 131 (55.98%) either alone or in combination. Neuroimaging showed predominant involvement of thalami, basal ganglia, and brainstem. Oral medications including anticholinergics, GABA agonists, and benzodiazepines followed by botulinum toxin were the most common treatment modalities.
CONCLUSION
Dystonia can be a disabling consequence of JE, and various available medical therapies can significantly improve the quality of life. Owing to insufficient studies on the assessment of dystonia associated with JE, longitudinal studies with a larger number of patients are warranted to further clarify the clinical course, treatment, and outcome of dystonia.
Topics: Dystonia; Dystonic Disorders; Encephalitis, Japanese; Humans; Movement Disorders; Quality of Life
PubMed: 35025122
DOI: 10.1002/brb3.2496 -
Experimental Brain Research Aug 2020Dystonia is a movement disorder characterised by involuntary muscle contractions resulting in abnormal movements, postures and tremor. The pathophysiology of dystonia is... (Review)
Review
Dystonia is a movement disorder characterised by involuntary muscle contractions resulting in abnormal movements, postures and tremor. The pathophysiology of dystonia is not fully understood but loss of neuronal inhibition, excessive sensorimotor plasticity and defective sensory processing are thought to contribute to network dysfunction underlying the disorder. Neurophysiology studies have been important in furthering our understanding of dystonia and have provided insights into the mechanism of effective dystonia treatment with pallidal deep brain stimulation. In this article we review neurophysiology studies in dystonia and its treatment with Deep Brain Stimulation, including Transcranial magnetic stimulation studies, studies of reflexes and sensory processing, and oscillatory activity recordings including local field potentials, micro-recordings, EEG and evoked potentials.
Topics: Deep Brain Stimulation; Dystonia; Dystonic Disorders; Globus Pallidus; Humans; Neurophysiology
PubMed: 32638036
DOI: 10.1007/s00221-020-05833-8 -
Movement Disorders : Official Journal... Jun 2013With increasing understanding of dystonia genetic etiologies and pathophysiology there has been renewed scrutiny and reappraisal of dystonia classification schemes and... (Review)
Review
With increasing understanding of dystonia genetic etiologies and pathophysiology there has been renewed scrutiny and reappraisal of dystonia classification schemes and nomenclature. One important category that includes both clinical and etiologic criteria is primary dystonia. This editorialized review discusses the impact of recent findings on primary dystonia criteria and argues that it remains useful in clinical and research practice. © 2013 Movement Disorder Society.
Topics: Brain; Dystonic Disorders; Genetic Predisposition to Disease; Humans; Terminology as Topic
PubMed: 23893447
DOI: 10.1002/mds.25528 -
Parkinsonism & Related Disorders Jan 2018The dystonias are a group of disorders defined by over-contraction of muscles leading to abnormal movements and postures. In recent years, enormous advances have been... (Review)
Review
INTRODUCTION
The dystonias are a group of disorders defined by over-contraction of muscles leading to abnormal movements and postures. In recent years, enormous advances have been made in elucidating the neurobiological mechanisms responsible for many types of dystonia.
METHODS
A literature review was conducted focusing on evolving concepts in dystonia genetics, anatomy and physiology.
RESULTS
The list of genes related to dystonia has grown from a relatively small number to more than 100. Concepts regarding the neuroanatomical basis for dystonia have evolved from a relatively narrow focus on dysfunction of the basal ganglia to a broader motor network model in which the basal ganglia, cerebellum, cerebral cortex, and other brain regions play a key role. Physiologically, our understanding of the core abnormalities has matured; and numerous changes in neural signaling have been revealed in the basal ganglia, cerebellum and cortex.
CONCLUSION
Although the dystonias share certain clinical aspects such as over-contraction of muscles leading to abnormal movements and postures, they actually comprise a very clinically and etiologically heterogeneous group of disorders. Understanding their neurobiological basis is important for devising rational therapies appropriately targeted for specific subgroups of patients.
Topics: Brain; Dystonic Disorders; Humans; Molecular Chaperones
PubMed: 28784298
DOI: 10.1016/j.parkreldis.2017.08.001