Does botulinum toxin affect psycho-social aspects in dystonia?

Dystonia is a movement disorder in which sustained muscle contractions give rise to abnormal postures or involuntary movements. It is a disabling and disfiguring disorder that affects activities of daily living and gives people a bizarre appearance often associated with psychological morbidity, embarrassment and social avoidance. Intramuscular injection of botulinum toxin (BoNT) is the most effective treatment for motor symptoms in focal dystonia, but little is known about its impact on the psycho-social dimension. The main aim of this study was to evaluate psycho-social changes in patients with focal dystonia after starting BoNT treatment using self-reported scales. The Beck Depression Inventory (BDI-II), the 36-Item Short Form Health Survey (SF-36), the Body Uneasiness Test (BUT), the State-Trait Anxiety Inventory (STAI) and the Visual Analogue Scale (VAS) assessing body self-image, satisfaction with physical aspects, social avoidance, self-reported depression, and self-distress were completed by 11 patients with dystonia and 9 patients with hyperhidrosis as a control group before BoNT (T0). VAS was then performed after four weeks (T1) to assess whether BoNT induced changes in the psychosocial dimension. Our results showed that only depressive symptoms and rumination about body defects improved in patients with dystonia after BoNT treatment, while improvement in self-distress and satisfaction with physical aspects was also found in hyperhidrosis. Individuals with hyperhidrosis experience poorer psychological well-being and suffer from higher levels of distress compared to dystonic patients. This suggests that individuals with this disabling condition are more vulnerable to social impact than dystonic patients.

Vibro-tactile stimulation of the neck reduces pain in people with cervical dystonia: a proof-of-concept study.

BACKGROUND: Pain is a common non-motor symptom in patients with cervical dystonia (CD), severely impacting their quality of life. The pathophysiology of CD is incompletely understood but it involves altered processing of proprioceptive and pain signals. OBJECTIVES: The purpose of this proof-of-concept study was to determine if vibro-tactile stimulation (VTS)-a non-invasive form of neuromodulation targeting the somatosensory system-can modulate neck pain in people with CD. METHODS: In a multi-center study, 44 CD patients received VTS to sternocleidomastoid and/or trapezius muscles for up to 45 min under 9 different stimulation conditions that either targeted a single or a pair of muscles. The primary outcome measure was a perceived pain score (PPS) rated by participants on a 100-point analogue scale. RESULTS: During VTS, 29/44 (66%) of participants experienced a reduction in PPS of at least 10% with 17/44 (39%) reporting a reduction in pain of 50% or higher. After VTS cessation, 57% of participants still reported a 10% or higher reduction in PPS. Effects were significant at the group level and persisted for up to 20 min post-treatment. No distinct optimal stimulation profiles were identified for specific CD phenotypes. Clinical markers of disease severity or duration did not predict the degree of VTS-induced pain reduction. CONCLUSION: This proof-of-concept study demonstrates the potential of VTS as a new non-invasive therapeutic option for treating neck pain associated with CD. Further research needs to delineate optimal dosage and long-term effects.

Genetic Update and Treatment for Dystonia.

A neurological condition called dystonia results in abnormal, uncontrollable postures or movements because of sporadic or continuous muscular spasms. Several varieties of dystonia can impact people of all ages, leading to severe impairment and a decreased standard of living. The discovery of genes causing variations of single or mixed dystonia has improved our understanding of the disease's etiology. Genetic dystonias are linked to several genes, including pathogenic variations of VPS16, TOR1A, THAP1, GNAL, and ANO3. Diagnosis of dystonia is primarily based on clinical symptoms, which can be challenging due to overlapping symptoms with other neurological conditions, such as Parkinson's disease. This review aims to summarize recent advances in the genetic origins and management of focal dystonia.

Focal dystonia in musicians, a literature review.

BACKGROUND: Musician's focal dystonia (mFD) is a rare, neurological, task-specific disorder that mainly affects the upper extremity (especially the hands) and generally appears as a painless muscular incoordination that can mark the end of a musician's professional career. The present literature review intends to highlight the current understanding of musician's focal dystonia, its underlying neural mechanisms and the role of prevention and treatment in physiotherapy, psychotherapy and other fields as occupational therapy. PURPOSE: The aim of the present literature review was to gain an overview of mFD in the medical, psychological and physical therapy literature and investigate what strategies for diagnosis and rehabilitation are available today. STUDY DESIGN: The present article is a literature review, based on the search for full-text publications with the goal of comparing the main strategies for mFD rehabilitation and prevention presented in the literature. METHODS: This literature review compared many relevant papers and studies available in literature today for mFD epidemiology, neural mechanisms, treatment and prevention, to discuss what we know today and highlight the aspects that can still be enhanced in the future. RESULTS: According to our results, current literature gives a good understanding of mFD epidemiology, but further studies are needed to fully comprehend the neurological aspects and develop more rehabilitation strategies, especially in the psychological field. Our research also highlighted the need for a multidisciplinary approach that considers both physical and psychological aspects. CONCLUSIONS: Physical rehabilitation strategies are helpful but, considering the amount of psychological aspects involved in mFD, a holistic approach should be considered and developed in the future. Finally, prevention must have a primary role in mFD treatment, raising awareness around it and, possibly, avoiding its development.

Multiple ectopic germinomas presenting as focal dystonia of fingers: a case report and literature review.

BACKGROUND: Intracranial primary germinomas predominantly develop on or near the midline structure in children and young adults and are diagnosed by brain imaging and biopsy. However, if brain imaging and pathology show unusual findings, it becomes difficult to make an accurate diagnosis. CASE REPORT: Herein, we report the case of a 14-year-old boy who presented with focal dystonia of the fingers as an initial symptom. Magnetic resonance imaging of the brain showed multifocal heterogeneous lesions with solid and cystic components involving the right frontal lobe, corpus callosum, left basal ganglia, and left corona radiata. A stereotactic biopsy of the right frontal lesion revealed several granulomatous areas with abundant inflammatory cells. After immunohistochemical staining, the patient was diagnosed with germinoma and treated with chemoradiotherapy according to the Korean Society for Pediatric Neuro-Oncology protocol. The patient has been in complete remission for five years. CONCLUSION: Germinomas can develop in intracranial off-midline structures, with unusual clinical, radiological, and pathological presentations. It is important to include intracranial germinomas in the differential diagnosis of infiltrative parenchymal tumors, especially in children.

Fatigue is related to depression in idiopathic dystonia.

INTRODUCTION: Dystonia is a movement disorder presented with involuntary muscle contraction causing abnormal posture, movement, or both. Besides motor symptoms, patients may also report non-motor symptoms such as pain, anxiety, apathy, depression, sleep problems, fatigue, and cognitive impairment. The etiology of fatigue in patients with dystonia is not yet well understood. AIM: To evaluate the presence of fatigue, depression, anxiety, sleep disorders, and daily sleepiness in patients with focal and segmental dystonia and to determine which of these non-motor symptoms influence the occurrence and severity of fatigue. PATIENTS AND METHODS: Patients were surveyed for symptoms of fatigue, depression, anxiety, night-time sleep problems, and daily sleepiness using the Fatigue Assessment Scale, Beck Depression Inventory II, Beck Anxiety Inventory, Pittsburgh Sleep Questionnaire Index, and Epworth Sleepiness Scale. Demographic data (sex, age, and disease duration) were collected from patient medical records. On statistical analysis, we used SPSS for Windows 10. The level of significance was set at p<0.05. RESULTS: Sixty patients (43 female and 17 male) with focal or segmental dystonia were evaluated. Fatigue was reported by 67.2% of patients. Fatigue (general, physical, and mental fatigue) was found to correlate with depression, anxiety, and sleep problems. Daily sleepiness correlated only with mental fatigue. Disease duration, age, and gender did not influence the symptoms of fatigue. Multiple regression analysis showed that depression mostly predicted symptoms of general, physical, and mental fatigue. CONCLUSION: Depression mostly predicted symptoms of general, physical, and mental fatigue in patients with focal and segmental dystonia.

Henry Meige: The man and his understanding of dystonia, at the turn of the 19th to 20th century.

BACKGROUND: Henry Meige (1866-1940), a French neurologist, the pupil of Charcot, is remembered for the eponym, the Meige syndrome, describing the clinical picture of craniocervical dystonia. This historical review highlights the controversies from his essay on "Le Juif Errant" (the Wandering Jew), and the evolution of his understanding of the movement disorders of the face and neck at the time of the encephalitis lethargica. RESULTS: His thesis reported 5 patients from Eastern Europe, presenting with functional neurological disorders following traumatic life experiences. He wrote with Feindel the first book on movement disorders "Les tics et leur traitement". He pioneered the concept of focal dystonia and distinguished the facial median spasm as a dystonic movement disorder of the face. He highlighted the co-existence of psychopathology and the influence of the mental on tics and dystonia. He coined with Brissaud and Feindel the term "geste antagoniste" in cervical dystonia. He emphasized the importance of self-management and psycho-motor retraining for focal dystonia. CONCLUSION: Meige made an invaluable contribution to our understanding of movement disorders, during his long medical career. The eponym Meige syndrome should be retained to describe an individual clinical entity.

[Neuromusculoskeletal disorders related to musical playing - a review of the literature]. / Les pathologies neuro-musculo-squelettiques en lien avec la pratique musicale. Une revue de la littérature.

The prevalence of pathologies associated with musical playing are high among professional musicians. While hearing injuries appear to be the most commonly disorder, instrumentalists are also prone to numerous neurological and musculoskeletal problems. Despite the increasing number of recent clinical studies, an appropriate identification of these problems by health practitioners remains difficult and the implementation of an adequate treatment is almost inexistent in a population of musicians with several disorders affecting the ability to play their instrument.

Les pathologies en lien avec la pratique musicale sont fréquentes dans une population de musiciens professionnels. Alors que les lésions auditives restent peut-être les seules connues du grand public, les musiciens sont aussi sujets à de nombreux troubles neurologiques et musculo-squelettiques. Malgré une augmentation récente des études cliniques, l'identification de ces troubles par les praticiens de la santé reste difficile et la mise en place de traitement est presque inexistante dans une population de musiciens présentant de nombreux troubles interférant avec la pratique de leur instrument.

Intact Organization of Tactile Space Perception in Isolated Focal Dystonia.

BACKGROUND: Systematic perceptual distortions of tactile space have been documented in healthy adults. In isolated focal dystonia impaired spatial somatosensory processing is suggested to be a central pathophysiological finding, but the structure of tactile space for different body parts has not been previously explored. OBJECTIVES: The objective of this study was to assess tactile space organization with a novel behavioral paradigm of tactile distance perception in patients with isolated focal dystonia and controls. METHODS: Three groups of isolated focal dystonia patients (cervical dystonia, blepharospasm/Meige syndrome, focal hand dystonia) and controls estimated perceived distances between 2 touches across 8 orientations on the back of both hands and the forehead. RESULTS: Stimulus size judgments differed significantly across orientations in all groups replicating distortions of tactile space known for healthy individuals. There were no differences between groups in the behavioral parameters we assessed on the hands and forehead. CONCLUSIONS: Tactile space organization is comparable between patients with isolated focal dystonia and healthy controls in dystonic and unaffected body parts. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Brain Structural Changes in Focal Dystonia-What About Task Specificity? A Multimodal MRI Study.

BACKGROUND: The neural basis of task specificity in dystonia is still poorly understood. This study investigated gray and white matter (WM) brain alterations in patients with task-specific dystonia (TSD) and non-task-specific dystonia (NTSD). METHODS: Thirty-six patients with TSD (spasmodic dysphonia, writer's cramp), 61 patients with NTSD (blepharospasm, cervical dystonia), and 83 healthy controls underwent 3D T1-weighted and diffusion tensor magnetic resonance imaging (MRI). Whole brain cortical thickness and voxel-based morphometry; volumes of basal ganglia, thalamus, nucleus accumbens, amygdala, and hippocampus; and WM damage were assessed. Analysis of variance models were used to compare MRI measures between groups, adjusting for age and botulinum toxin (BoNT) treatment. RESULTS: The comparison between focal dystonia patients showed cortical thickness and gray matter (GM) volume differences (ie, decreased in NTSD, increased in TSD) in frontal, parietal, temporal, and occipital cortical regions; basal ganglia; thalamus; hippocampus; and amygdala. Cerebellar atrophy was found in NTSD patients relative to controls. WM damage was more severe and widespread in task-specific relative to NTSD patients. TSD patients receiving BoNT, relative to nontreated patients, had cortical thickening and increased GM volume in frontoparietal, temporal, and occipital regions. NTSD patients experiencing pain showed cortical thickening of areas involved in pain-inhibitory mechanisms. CONCLUSIONS: TSD and NTSD are characterized by opposite alterations of the main cortical and subcortical sensorimotor and cognitive-controlling brain structures, suggesting the possible presence of different pathophysiological and/or compensatory mechanisms underlying the complexity of the two clinical phenotypes of focal dystonia. © 2020 International Parkinson and Movement Disorder Society.

Comparative study between idiopathic and non-idiopathic dystonia: a prospective observational study.

BACKGROUND: There are very few studies based on the updated dystonia classification. However, a comparison of the idiopathic and non-idiopathic dystonias based on the newer classification has not been done previously. OBJECTIVES: To study and compare the clinicoetiological profile of patients with idiopathic and non-idiopathic dystonia attending a movement disorder clinic of a tertiary care teaching institution. METHODS: All the consecutive dystonia patients from October 2017 to September 2019 fulfilling the inclusion criteria were subjected to a detailed clinical evaluation. Investigations were performed as per requirement. Patients were classified according to the consensus update on phenomenology and classification of dystonia. RESULTS: A total of 183 patients with dystonia were included, with 61.7% (113) males and 38.3% (70) females. The idiopathic group revealed a significantly earlier age of onset with cases slightly outnumbering (n = 96/183, 52.5%) the non-idiopathic group (n = 87/183, 47.5%). Focal dystonias were the commonest type in both the idiopathic (n = 58/96, 60.4%) and non-idiopathic groups (n = 30/87, 34.5%), while generalized dystonia accounted for 26.4% (n = 23/87) of the non-idiopathic cases and only 3.1% (n = 3/96) of the idiopathic cases. The majority of idiopathic cases were isolated dystonia (n = 93/96, 96.9%), while all hemidystonias were non-idiopathic. CONCLUSION: Focal dystonias were the commonest in both idiopathic and non-idiopathic groups, while generalized dystonia was significantly commoner in the non-idiopathic group. Acquired causes like drugs, perinatal insult were the commonest etiology in the non-idiopathic group. Hemidystonia was found exclusively in the non-idiopathic acquired group.

CACNA1B gene variants in adult-onset isolated focal dystonia.

BACKGROUND: Isolated focal dystonia (IFD) is a heterogeneous group of potentially invalidating movement disorders. The etiopathogenesis is complex, both genetic and environmental factors playing a role, but remains elusive. The CACNA1B gene codes for the N-type neuronal voltage-gated calcium channels CaV2.2, which may play a role in the development of some IFD. METHODS: We analyzed samples from the GENDYS cohort for mutations in CACNA1B gene, using targeted next-generation sequencing (NGS). RESULTS: The GENDYS cohort consists of 120 people with adult-onset IFD (cervical dystonia 47.5%, blepharospasm 47.2%, others 8.3%). Of these, 35% had subsequent topographical extension. Average age at onset was 42 and average disease durations 8 years. Targeted NGS revealed a novel frameshift mutation c.2291AGG > A, in exon 19, and a previously reported variant, c.6834T > G, in exon 47. CONCLUSION: Our findings suggest that disease-causing mutations in CACNA1B gene may be involved in the development of some adult-onset IFD. To our knowledge, this is the first study that identified a disease-causing CACNA1B gene mutation in association with adult-onset IFD.

The Use of Botulinum Toxin for Treatment of the Dystonias.

Dystonias are characterized by involuntary muscle contractions, twisting movements, abnormal postures, and often tremor in various body regions. However, in the last decade several studies have demonstrated that dystonias are also characterized by sensory abnormalities. While botulinum toxin is the gold standard therapy for focal dystonia, exactly how it improves this disorder is not entirely understood. Neurophysiological studies in animals and humans have clearly demonstrated that botulinum toxin improves dystonic motor manifestations by inducing chemodenervation, therefore weakening the injected muscles. In addition, neurophysiological and neuroimaging evidence also suggests that botulinum toxin modulates the activity of various neural structures in the CNS distant from the injected site, particularly cortical motor and sensory areas. Concordantly, recent studies have shown that in patients with focal dystonias botulinum toxin ameliorates sensory disturbances, including reduced spatial discrimination acuity and pain. Overall, these observations suggest that in these patients botulinum toxin-induced effects encompass complex mechanisms beyond chemodenervation of the injected muscles.

[How to explore a blepharospasm]. / Comment j'explore un blépharospasme.

Blepharospasm is a particularly distressing form of focal dystonia, specifically affecting the eyelids and causing involuntary closing of the eyes or an increased blinking. Despite its frequency, the diagnosis of this condition is often delayed. Diagnostic criteria are mainly clinical, but sometimes further investigations may be necessary as blepharospasm may be included in a complex clinical picture.

Le blépharospasme est une forme de dystonie focale particulièrement invalidante, touchant spécifiquement les paupières et engendrant une fermeture involontaire des yeux ou un clignement palpébral excessif. Malgré sa fréquence, cette affection souffre d'un délai de diagnostic souvent trop long. Celui-ci est avant tout clinique, mais il ne faut pas méconnaître des formes s'intégrant au sein de tableaux neurologiques complexes et nécessitant une mise au point plus complète.

Aberrant Somatosensory-Motor Adaptation in Musicians' Dystonia.

BACKGROUND: Some forms of movement disorders are characterized by task-specific manifestations of symptoms. However, its underlying mechanisms are poorly understood. Here we addressed this issue through a novel motor adaptation experimental paradigm. METHODS: Pianists with and without focal task-specific dystonia learned to play the piano with a key whose weight can be modified by a novel robot system. RESULTS: The result clearly demonstrated a significantly larger error between the target and produced keystroke velocities in the patients than the controls following a repetition of keystrokes of the weighted key. This adaptation failure was not correlated with the variability of timing and velocity of the keystroke when the patients were playing unloaded piano keys, which suggests distinct effects of focal task-specific dystonia on motor adaptation and fine motor control. Immediately after a repetition of the strikes of the heavy key with keeping the fingers adducted, the error of the keystroke velocity when striking the key with the fingers more abducted was maintained in both the patients and controls. This generalization of the adaptation across different hand postures suggests that motor memory of dynamics of the piano key is independent of biomechanical properties of the hand. Importantly, a lack of difference in the finger muscular strength between the groups indicated that the adaptation failure was not attributed to deficit of muscular strength in the patients. CONCLUSIONS: These findings suggest that task-specific manifestation of dystonic movements in focal task-specific dystonia is associated with malfunctions of internal representation of mechanical properties of a well-trained tool. © 2020 International Parkinson and Movement Disorder Society.

Deep brain stimulation for dystonia in Finland during 2007-2016.

BACKGROUND: Dystonia is a movement disorder substantially affecting the quality of life and the ability to work. A proportion of patients does not respond to first line pharmacotherapy. Deep brain stimulation (DBS) is established as a primary operative treatment option for severe drug resistant dystonia. We studied dystonia patients treated with DBS in Finland between the years 2007-2016 to evaluate the use and outcomes of DBS treatment. METHODS: We analysed the hospital records of dystonia patients, who underwent DBS operation during 2007-2016 in Finland. The clinical and technical parameters were recorded as well as preoperative assessments and treatments. The response to DBS was evaluated retrospectively using the Global Dystonia Rating Scale (GDS). RESULTS: Out of 585 dB implantations during the study period, 37 were done for dystonia. The clinical response improved significantly with time in the isolated focal dystonia group, and at 12 months, 22 of 32 patients had over 50% alleviation of the GDS score. There was only one subclinical intracerebral haemorrhage, and four infections leading to revision. Speech impairment and limb coordination problems were common stimulation- related adverse events and were mostly resolved or relieved with the adjustment of stimulation parameters. CONCLUSIONS: DBS seems to be beneficial in dystonia. Although DBS is indicated for dystonia in Finland, the number of operations did not increase at the same rate as DBS operations in general. DBS appears to be a safe and effective treatment for focal as well as generalized dystonia.

Expert recommendations for diagnosing cervical, oromandibular, and limb dystonia.

BACKGROUND: Diagnosis of focal dystonia is based on clinical grounds and is therefore open to bias. To date, diagnostic guidelines have been only proposed for blepharospasm and laryngeal dystonia. To provide practical guidance for clinicians with less expertise in dystonia, a group of Italian Movement Disorder experts formulated clinical diagnostic recommendations for cervical, oromandibular, and limb dystonia. METHODS: A panel of four neurologists generated a list of clinical items related to the motor phenomenology of the examined focal dystonias and a list of clinical features characterizing neurological/non-neurological conditions mimicking dystonia. Thereafter, ten additional expert neurologists assessed the diagnostic relevance of the selected features and the content validity ratio was calculated. The clinical features reaching a content validity ratio > 0.5 contributed to the final recommendations. RESULTS: The recommendations retained patterned and repetitive movements/postures as the core feature of dystonia in different body parts. If present, a sensory trick confirmed diagnosis of dystonia. In the patients who did not manifest sensory trick, active exclusion of clinical features related to conditions mimicking dystonia (features that would be expected to be absent in dystonia) would be necessary for dystonia to be diagnosed. DISCUSSION: Although reliability, sensitivity, and specificity of the recommendations are yet to be demonstrated, information from the present study would hopefully facilitate diagnostic approach to focal dystonias in the clinical practice and would be the basis for future validated diagnostic guidelines.

Assessment of the effects of Kinesiotaping on musical motor performance in musicians suffering from focal hand dystonia: a pilot study.

OBJECTIVE: The aim of this study was to explore the immediate and short-term effects of a Correction Kinesiotaping intervention on fine motor control in musicians with focal hand dystonia. DESIGN: A single-blinded, single-arm repeated measures, pilot study. SETTING: Medical outpatient clinic. SUBJECTS: Seven musicians diagnosed with focal hand dystonia. INTERVENTIONS: Musicians performed musical exercises under the following conditions: without Kinesiotape (baseline), during a Correction Kinesiotaping intervention and immediately after tape removal (block 1) and during a Sham Kinesiotaping intervention and immediately after tape removal (block 2). Blocks were randomly presented across participants. A tailored Correction Kinesiotaping intervention on affected fingers was provided based on the dystonic pattern that each patient manifested while playing. MAIN MEASURES: Motor performance was video-documented and independent experts blindly assessed the general performance and fingers' posture on visual analogue scales. Also, musicians' self-reports of the musical abilities were evaluated. Finally, electromyographic activity and coactivation index of wrist antagonist muscles were analyzed. RESULTS: No significant differences in effects between Correction Kinesiotaping and Sham Kinesiotaping were reported by the experts, either for general performance (P > 0.05) or for fingers' posture (P > 0.05); any subtle benefits observed during Correction Kinesiotaping were lost after the tape was removed. Musicians estimated that Correction Kinesiotaping was ineffective in improving their musical abilities. Also, no significant changes with respect to the coactivation index (P > 0.05) were found among the conditions. CONCLUSION: Correction Kinesiotaping intervention may not be useful to reduce dystonic patterns, nor to improve playing ability, in musicians with focal hand dystonia.

Perceptual decisions based on previously learned information are independent of dopaminergic tone.

Both cognitive and motor symptoms in people with Parkinson's disease (PD) arise from either too little or too much dopamine (DA). Akinesia stems from DA neuronal cell loss, and dyskinesia often stems from an overdose of DA medication. Cognitive behaviors typically associated with frontal cortical function, such as working memory and task switching, are also affected by too little or too much DA in PD. Whether motor and cognitive circuits overlap in PD is unknown. In this article, we show that whereas motor performance improves in people with PD when on dopaminergic medication compared with off medication, perceptual decision-making based on previously learned information (priors) remains impaired whether on or off medications. To rule out effects of long-term DA treatment and dopaminergic neuronal loss such as occur in PD, we also tested a group of people with dopa-unresponsive focal dystonia, a disease that involves the basal ganglia, like PD, but has motor symptoms that are insensitive to dopamine treatment and is not thought to involve frontal cortical DA circuits, unlike PD. We found that people with focal dystonia showed intact perceptual decision-making performance but impaired use of priors in perceptual decision-making, similar to people with PD. Together, the results show a dissociation between motor and cognitive performance in people with PD and reveal a novel cognitive impairment, independent of sensory and motor impairment, in people with focal dystonia. The combined results from people with PD and people with focal dystonia provide mechanistic insights into the role of basal ganglia non-dopaminergic circuits in perceptual decision-making based on priors.

Task-specificity in focal dystonia is shaped by aberrant diversity of a functional network kernel.

OBJECTIVES: Task-specific focal dystonia selectively affects the motor control during skilled and highly learned behaviors. Recent data suggest the role of neural network abnormalities in the development of the pathophysiological dystonic cascade. METHODS: We used resting-state functional MRI and analytic techniques rooted in network science and graph theory to examine the formation of abnormal subnetwork of highly influential brain regions, the functional network kernel, and its influence on aberrant dystonic connectivity specific to affected body region and skilled motor behavior. RESULTS: We found abnormal embedding of sensorimotor cortex and prefrontal thalamus in dystonic network kernel as a hallmark of task-specific focal dystonia. Dependent on the affected body region, aberrant functional specialization of the network kernel included regions of motor control management in focal hand dystonia (writer's cramp, musician's focal hand dystonia) and sensorimotor processing in laryngeal dystonia (spasmodic dysphonia, singer's laryngeal dystonia). Dependent on skilled motor behavior, the network kernel featured altered connectivity between sensory and motor execution circuits in musician's dystonia (musician's focal hand dystonia, singer's laryngeal dystonia) and abnormal integration of sensory feedback into motor planning and executive circuits in non-musician's dystonia (writer's cramp, spasmodic dysphonia). CONCLUSIONS: Our study identified specific traits in disorganization of large-scale neural connectivity that underlie the common pathophysiology of task-specific focal dystonia while reflecting distinct symptomatology of its different forms. Identification of specialized regions of information transfer that influence dystonic network activity is an important step for future delineation of targets for neuromodulation as a potential therapeutic option of task-specific focal dystonia. © 2018 International Parkinson and Movement Disorder Society.