Task-specific Movement Disorder Research Articles

Laryngeal dystonia: Phenomenology, genetics, and management

Laryngeal dystonia is a task-specific movement disorder causing abnormal movement of the adductor or abductor muscles of the vocal folds. In 1984, Blitzer pioneered the first use of onabotulinum toxin A to treat this disorder. Over 1400 patients were diagnosed with laryngeal dystonia in the last thirty years. In this paper, we summarize their clinical and endoscopic findings as well as treatment results. We also summarize the underlying genetics of the disorder.82% of patients were diagnosed with adductor type laryngeal dystonia and 17% of patients manifested an abductor laryngeal dystonia. Patients with adductor dystonia were treated with toxin to the thyroarytenoid muscles and those with abductor dystonia were treated with toxin to the posterior cricoarytenoid muscle. All patient achieved greater than 70% improvement in percent normal function. Laryngeal dystonia is a rare movement disorder of the larynx with an incidence of approximately 35.1 per 100,000 individuals (Simonyan et al., 2021). Presently, there is no cure for laryngeal dystonia, but botulinum toxin has shown significant success in treating the symptoms of the disorder.

Practice behaviors as trigger factor for the onset of Musicians’ Dystonia

Musician’s Dystonia (MD) is a task-specific movement disorder that results in an involuntary cramping of muscles involved in playing an instrument such as the upper limbs or the embouchure. It is usually painless and occurs in general only at the instrument. The pathophysiology of MD is not completely understood. The present study aimed at assessing differences in practice behaviors between pianists affected by MD and Healthy Controls (HC) in the years preceding the onset of the disease. Thus, we investigated to what extent practice quantity can be considered a trigger of Musicians’ Dystonia. The results showed that despite comparable practice behaviors in childhood, MD pianists incremented the amount of daily practice to a greater extent than their healthy colleagues, especially in the second and in the third decade of life. Thus, subsequent logistic regression analysis showed that high amounts of daily practice might significantly increase the risk of developing MD. Furthermore, gender-related differences in practice behaviors across groups were identified, indicating that male pianists from the MD group might not have practiced significantly more than HC male pianists before the onset of the disease. To the authors’ knowledge, these are the first empirical evidence of the role of dysfunctional practice behaviors in triggering MD, which has clinical and educational implications.

Reliability and Validity of the Embouchure Dystonia Severity Rating Scale.

Embouchure dystonia (ED) is a task-specific movement disorder that leads to loss of fine motor control of the embouchure and tongue muscles in wind musicians. In contrast to musicians' hand dystonia, no validated severity rating for ED exists, posing a major obstacle for structured assessment in scientific and clinical settings. The aim of this study is to validate an ED severity rating scale (EDSRS) allowing for a standardized estimation of symptom severity in ED. The EDSRS was set up as a composite score of six items evaluating audio-visual disease symptoms during the performance of three standardized musical tasks (sustained notes, scales, and fourths) separately for each body side. For validation, 17 musicians with ED underwent standardized audiovisual recordings during performance. Anonymized and randomized recordings were assessed by two experts in ED (raters). Statistical analysis included metrics of consistency, reliability, and construct validity with the fluctuation of the fundamental frequency of the acoustic signal (F0) (extracted in an audio analysis of the sustained notes). The EDSRS showed high internal consistency (Cronbach's α = 0.975-0.983, corrected item-total correlations r = 0.90-0.96), interrater reliability (intraclass correlation coefficient [ICC] for agreement/consistency = 0.94/0.96), intrarater reliability over time (ICC per rater = 0.93/0.87) and good precision (standard error of measurement = 2.19/2.65), and correlated significantly with F0 variability (r = 0.55-0.60, p = 0.011-0.023). The developed EDSRS is a valid and reliable tool for the assessment of ED severity in the hands of trained expert raters. Its easy applicability makes it suitable not only for routine clinical practice but also for scientific studies.

Movement patterns in tuba playing: comparison of an embouchure dystonia case with healthy professional tuba players using real-time MRI imaging.

Musculoskeletal problems in professional brass musicians are very common and often involve the muscles of the embouchure. In rare cases, embouchure dystonia (EmD), a task-specific movement disorder with a wide symptomatic and phenotypic variability, occurs. Following trumpeters and horn players, professional tuba players with and without EmD have now been studied using the latest real-time MRI technology to better understand the underlying pathophysiology. In the present study, the tongue movement patterns of 11 healthy professional artists and one subject suffering from EmD were compared. The tongue position in the anterior, intermediary and posterior oral cavity were converted into pixel positions based on seven previously generated profile lines, using the established software MATLAB. These data allow a structured comparison of tongue movement patterns between the patient and the healthy subjects, as well as between individual exercises. The main focus of the analysis was on an ascending 7-note harmonic series performed in different playing techniques (slurred, tongued, tenuto and staccato). Playing the ascending harmonics, a noticeable ascending tongue movement could be observed in the anterior part of the oral cavity in healthy tubists. In the posterior region, there was a slight decrease in oral cavity space. In the EmD patient, hardly any movement was observed at the tongue apex, but in the middle and posterior regions of the oral cavity there was an increase in size the higher the tone became. These distinct differences are relevant for the characterization and a better understanding of the clinical presentation of EmD. Concerning different playing techniques, it was apparent, that notes played slurred or staccato resulted in a larger oral cavity when compared to notes played tongued or tenuto, respectively. By using real-time MRI videos, the tongue movements of tuba players can be clearly observed and analyzed. The differences between healthy and diseased tuba players demonstrate the great effects of movement disorders in a small area of the tongue. In order to better understand the compensation of this motor control dysfunction, further studies should investigate further parameters of tone production in all brass players with a larger number of EmD patients additional to the observed movement patterns.

Treating the musician rather than the symptom: The holistic tools employed by current practices to attend to the non-motor problems of musicians with task-specific focal dystonia.

Musicians Focal Dystonia (MFD) is a task-specific movement disorder affecting highly skilled musicians. The pathophysiology is poorly understood, and the available treatments are unable to fully and reliably rehabilitate the affected skill. Recently, the exclusively neurological nature of the condition has been questioned, and additional psychological, behavioral, and psychosocial contributing factors were identified. However, very little is known about how these factors influence the recovery process, and how, if at all, they are addressed in ongoing practices. For this study, 14 practitioners with substantial experience in working with musicians with MFD were interviewed about the elements in their approach which are directed at the cognition, emotions, attitudes, and behaviors of their patients and clients. A wide variety of tools were reported in three areas: (1) creating a supportive learning environment and addressing anxiety and perfectionism, (2) using body-oriented methods to optimize the playing behaviors and (3) consciously channeling the focus of attention to guide the physical retraining exercises and establishing new habits. The study also revealed that in-depth knowledge of the instrumental technique is profitable to retrain the impaired motor patterns. Therefore, the importance of including music educators in developing new therapeutic approaches will also be highlighted.

Musicians Focal Dystonia: The Practitioner's Perspective on Psychological, Psychosocial, and Behavioural Risk Factors and Non-motor Symptoms.

Musician's focal dystonia (MFD) is a painless, task-specific neurological movement disorder that impairs fine motor control when playing an instrument. The pathophysiology is not fully understood, and while the available treatment strategies can help with improving motor control, they are rarely able to fully and reliably rehabilitate playing skills. Recent studies suggest that apart from genetic factors, maladaptive neuroplasticity, and the repetitive nature of the instrumental technique, psychosocial, psychological, and behavioural factors might also play a role in the onset of MFD. However, the presence of some of these risk factors is supported primarily by anecdotal evidence, with only a few aspects examined empirically. To explore this area further, 14 semi-structured interviews were conducted with a convenience sample of practitioners (8 medical professionals and 6 musician-coaches) who frequently treated MFD sufferers. Throughout their career, these participants are estimated to have interacted with more than 2,000 musicians with MFD, creating a large, indirect sample. A detailed patient profile emerged from the data with three main components: 1) the negative impact of social environments, including traumatic experiences and low quality of instrumental teaching; 2) a perfectionist, anxious, overly sensitive, and acquiescent personality type; and 3) obsessive, controlling, and inadequate practice behaviours. Participants stated MFD needs to be treated holistically and that neglecting these aspects during treatment could jeopardise rehabilitation. Further objective, controlled research trials are needed to describe these factors in detail, quantify their potential impact as risk factors, and understand how they might hinder therapy.

Towards a Holistic Understanding of Musician's Focal Dystonia: Educational Factors and Mistake Rumination Contribute to the Risk of Developing the Disorder.

Musicians’ Focal Dystonia (MFD) is a task-specific neurological movement disorder, affecting 1–2% of highly skilled musicians. The condition can impair motor function by creating involuntary movements, predominantly in the upper extremities or the embouchure. The pathophysiology of the disorder is not fully understood, and complete recovery is extremely rare. While most of the literature views the condition through a neurological lens, a handful of recent studies point out certain psychological traits and the presence of adverse playing-related experiences and preceding trauma as possible contributors to the onset. The nature and the frequency of these factors, however, are under-researched. The present quasi-experimental study aimed to compare musicians with and without MFD in terms of the frequency of various adverse psychosocial and psychological factors to explore their contribution to the onset of the condition. Professional musicians with MFD (n = 107) and without MFD (n = 68) were recruited from online platforms, musicians’ unions, and organisations to fill out a survey. The survey was based on two previously conducted interview studies and included the Student-Instructor Relationship Scale (SIRS), the Mistake Rumination Scale (MRS), the Trauma History Screen, and self-constructed questions about the received music education, early success, and personal experiences. To identify potential risk factors, independent samples t-tests were conducted and found that there are significant differences in musicians with and without MFD in terms of mistake rumination, early success, and the received music education. A logistic regression showed that six factors contributed to the construct to various extents; we observed a significant model [χ2(80) = 22.681, p < 0.001], which predicted 71.2% of the cases correctly. This exploratory study shows that psychological and psychosocial factors might play a role in the development of MFD. Understanding these in more detail could inform preventative strategies and complement the current therapeutic approaches to support this vulnerable population better.

Influence of Adverse Childhood Experiences and Perfectionism on Musician's Dystonia: a Case Control Study.

Background:Musician’s dystonia (MD) is a task-specific movement disorder characterized by muscle cramps and impaired voluntary motor-control whilst playing a musical instrument. Recent studies suggest an involvement of adverse childhood experiences (ACEs) in the development of MD.Objectives:By investigating the prevalence of ACEs in MD patients with perfectionism as possible mediating factor this study aims to gain further insights into the etiology of MD.Methods:The Adverse Childhood Experiences Scale (ACE-S), the Childhood Trauma Questionnaire (CTQ) and Frost’s Multidimensional Perfectionism Scale (FMPS) were answered by 128 MD patients and 136 healthy musicians. Regression and mediator analyses were conducted to identify relevant predictors of MD and to investigate the role of perfectionism.Results:The CTQ total score (OR: 1.04; 95% CI [1.01, 1.08]) and the sub-score “emotional neglect” (OR: 1.13; 95% CI [1.02, 1.25]) were identified as two predictors of MD. Patients scored significantly higher on the sub-score emotional neglect, but no significant differences were observed for other forms of ACEs. Perfectionism had no mediating function on the association between ACEs and MD.Discussion:Though only slight differences between both groups were found, there is a trend towards higher rates of emotional neglect among dystonic musicians. A possible explanation for the association between musician’s dystonia and emotional neglect could be a lower stress resilience in musicians with a history of ACEs, which increases vulnerability to acquire dysfunctional movement patterns.These tendencies should be further investigated in future studies in which the MD and HM groups are more evenly matched in sex and age.HighlightsWe investigated the role of Adverse Childhood Experiences in the development of musician’s dystonia, comparing a large sample of healthy musicians and dystonia patients. Our findings suggest that experiencing emotional neglect might increase the probability to acquire musician’s dystonia. The findings offer new implications for etiology and treatment of dystonia.

The Dutch Yips Study: Results of a Survey Among Golfers.

Background:The yips in golf is currently regarded as a task-specific movement disorder, with variable phenomenology and of unclear etiology. There is some overlap with task-specific dystonia (TSD), which has also been reported in other sports. The objective was to further characterize the yips in terms of its prevalence and related factors.Methods:Recreational golfers from one of the larger golf clubs in the Netherlands aged 18 years or older, filled in an anonymous, web-based questionnaire with items on demographic, medical and lifestyle factors, specific yips-relevant items, as well as fanaticism, familial presence of yips, obsessive-compulsive traits, and a dystonia questionnaire.Results:In total, 234 golfers (26%) completed the questionnaire, among whom 52 (22%, 95% CI: 17–28%) reported to suffer from the yips. In comparison to their non-yips counterparts, the yips group was characterized by a larger proportion of men, more current or past smoking, better golf skills, longer history of playing golf, and more familial yips occurrence.Discussion:Golfer’s self-reported yips may be very frequent in a group of responding amateur golfers and associated factors seems to include male gender, current or past smoking, extensive golf experience and skills, and a positive family history of the yips. Further work to better understand the origin and nature of the yips is needed.

Impact of Psychic Traumatization on the Development of Musicians' Dystonia: Six Exploratory Case Studies.

Musician's dystonia represents a special case of focal dystonia. It is described as a task-specific movement disorder which presents itself as muscular incoordination or loss of voluntary fine-motor control of extensively trained movements while a musician is playing the instrument. Several triggering factors have been identified, such as overuse, chronic pain, perfectionism, and anxiety disorders. As a common feature, dysfunctional self-management and stress-coping mechanisms are at the root of the aforementioned behaviors. Based on long-term experience from our musicians' medicine outpatient clinic, we hypothesized that early psychic or somatic traumatization may be an underlying mechanism and therefore contribute essentially to focal dystonia. In a qualitative study, we investigated the role of early traumatization as a potential cause of motor failures, such as musician's dystonia, employing an episodic interview on a sample of six professional musicians (age 30-57 yrs, 5:1 M:F) suffering from musician's dystonia. Using grounded theory methodology, we were able to derive one generalized etiological model describing contributing factors in the etiological understanding of focal dystonia from the six case studies. The qualitative interviews clearly revealed that all patients experienced early psychic traumatizations, including violence and parents' substance abuse. In this small sample, we theorize that in-depth, early traumatization most probably led to a dysfunctional stress-coping mechanism. We therefore propose in our model that there are two types of motor failures, one linked to stressful experiences, dysfunctional coping behaviors, and increased muscle tone, and one linked to genetic susceptibility of the motor-system without psychological triggering factors.

Rehabilitation of focal hand dystonia in musicians: a systematic review of the studies.

Focal hand dystonia in musicians is a task-specific movement disorder characterized by an involuntary loss of control and coordination of finger movements during instrumental playing. Literature searches with the keywords 'dystonia' AND 'musician' AND 'finger' OR 'treatment' OR 'therapy' OR 'rehabilitation' were conducted in PubMed, EMBASE, Cochrane Library and Web of Science to perform the systematic review about the several strategies used to treat dystonia in musicians. The search was performed independently by two authors (R.C. and M.V.) from 6 April 2020 till 6 June 2020. The research identified a total of 423 articles. Seventy-seven selected articles were analysed by the reviewers. Thirty-six publications met the inclusion criteria and were included in the systematic review. The systematic review was performed to identify the main used treatments for dystonia in musicians. We defined the several techniques to better guide the physician to delineate a rehabilitation protocol adopting the better strategies described in the current literature. This systematic review tried to provide to the reader a complete overview of the literature of all possible different treatments for dystonia in musicians. A correct protocol could permit to improve the motor performance and the quality of life of musicians.

Neuropsychological Aspects of Focal Dystonia in Musicians

Abstract. Musician’s dystonia (MD) is a focal, task-specific neurological movement disorder that presents with loss of voluntary motor control when playing the instrument and affects up to 1–2 % of professional musicians. The current pathophysiological understanding of MD is that of a network disease, involving the sensorimotor cortex, basal ganglia, cerebellum and the limbic system. Various extrinsic factors, e.g. high temporal and spatial sensorimotor constraints on the instrument or more than 10 000 hours of accumulated practice time, as well as intrinsic factors, e.g. high levels of anxiety and perfectionism, and even genetic factors have been identified to increase the risk to develop MD. From a neuropsychological point of view, two phenotypes of MD can be distinguished with high or low psychological stress, which should be taken into account to adapt the individual therapy. Treatment options for MD include medication with trihexyphenidyl, local injections of botulinum toxin A, retraining, ergonomic changes of the instrument, and in patients with high psychological stress also antidepressants and behavioral therapy.

Tongue involvement in embouchure dystonia: new piloting results using real-time MRI of trumpet players

BackgroundThe embouchure of trumpet players is of utmost importance for tone production and quality of playing. It requires skilled coordination of lips, facial muscles, tongue, oral cavity, larynx and breathing and has to be maintained by steady practice. In rare cases, embouchure dystonia (EmD), a highly task specific movement disorder, may cause deterioration of sound quality and reduced control of tongue and lip movements. In order to better understand the pathophysiology of this movement disorder, we use real-time MRI to analyse differences in tongue movements between healthy trumpet players and professional players with embouchure dystonia.MethodsReal-time MRI videos (with sound recording) were acquired at 55 frames per second, while 10 healthy subjects and 4 patients with EmD performed a defined set of exercises on an MRI-compatible trumpet inside a 3 Tesla MRI system. To allow for a comparison of tongue movements between players, temporal changes of MRI signal intensities were analysed along 7 standardized positions of the tongue using a customised MATLAB toolkit. Detailed results of movements within the oral cavity during performance of an ascending slurred 11-note harmonic series are presented.ResultsPlaying trumpet in the higher register requires a very precise and stable narrowing of the free oral cavity. For this purpose the anterior section of the tongue is used as a valve in order to speed up airflow in a controlled manner. Conversely, the posterior part of the tongue is much less involved in the regulation of air speed. The results further demonstrate that healthy trumpet players control movements of the tongue rather precisely and stable during a sustained tone, whereas trumpet players with EmD exhibit much higher variability in tongue movements.ConclusionControl of the anterior tongue in trumpet playing emerges as a critical feature for regulating air speed and, ultimately, achieving a high-quality performance. In EmD the observation of less coordinated tongue movements suggests the presence of compensatory patterns in an attempt to regulate (or correct) pitch. Increased variability of the anterior tongue could be an objective sign of dystonia that has to be examined in further studies and extended to other brass instruments and may be also a potential target for therapy options.

Velopharyngeal Dystonia: An Unusual Focal Task-specific Dystonia?

<strong>Background:</strong> Velopharyngeal dysfunction produces a nasal speech pattern because of the inability to close the nasal airway during speech, most often associated with anatomical abnormalities of the palate. <strong>Case Report:</strong> We describe two cases of possible velopharyngeal dystonia, a task-specific movement disorder causing a speech pattern similar to velopharyngeal dysfunction. Both patients experienced treatment response with anticholinergic medication. <strong>Discussion:</strong> Dystonia affecting speech via involvement of the pharyngeal musculature may be an unrecognized etiology of voice disorders.

Sensory feedback - Dependent neural de-orchestration: The effect of altered sensory feedback on Musician's Dystonia.

Musician's dystonia (MD) is a task-specific movement disorder related to extensive expert music performance training. Similar to other forms of focal dystonia, MD involves sensory deficits and abnormal patterns of sensorimotor integration. The present study investigated the impaired cortical sensorimotor network of pianists who suffer from MD by employing altered auditory and tactile feedback during scale playing with multichannel EEG. 9 healthy professional pianists and 9 professional pianists suffering from right hand MD participated in an experiment that required repeated scale playing on a MIDI piano under altered sensory feedback while EEG was measured. The comparison of EEG data in healthy pianists and pianists suffering from MD revealed a higher degree of inter-regional phase synchronisation between the frontal and parietal regions and between the temporal and central regions in the patient group and in conditions that are relevant to the long-trained auditory-motor coupling (normal auditory feedback and complete deprivation of auditory feedback), but such abnormalities decreased in conditions with delayed auditory feedback and altered tactile feedback. These findings support the hypothesis that the impaired sensorimotor integration of MD patients is specific to the type of overtrained task that the patients were trained for and can be modified with altered sensory feedback.

Self-report vs. kinematic screening test: prevalence, demographics, and sports biography of yips-affected golfers

The yips is considered a task-specific movement disorder. Its estimated prevalence, however, is high compared to similar neurological movement disorders, possibly resulting from previous studies’ restriction of samples based on skill level, and self-report bias. Alternatively, this high prevalence might be an indication of additional aetiologies, for example the influence of previously played racket sports. We estimated the prevalence of the putting yips across the skill range, using self-reports in one study and a screening test in a second study. We explored if previously played sports matter for the development of the yips. In study 1, yips prevalence (N = 1,306) and golfers’ sports biographies (n = 264) were examined via two online surveys, in which golfers indicated if they were yips-affected. In study 2, golfers (N = 186) putted in a standardised putting test while kinematic and performance measures were recorded. Prevalence was estimated via a kinematic threshold. Sports biographies (n = 119) were obtained via an online survey. Prevalence of currently yips-affected golfers was 22.4% in study 1 and 16.7% in study 2. In both studies, more yips-affected than unaffected golfers had experience in playing racket sports. Yips prevalence remained higher than previously estimated prevalence of other movement disorders but decreased when the whole skill range including professionals and novices was considered. Future studies should use the kinematic screening test instead of self-reports to detect the yips and further investigate the influence of previously played racket sports.

Sensory trick phenomenon improves motor control in pianists with dystonia: prognostic value of glove-effect

Musician’s dystonia (MD) is a task-specific movement disorder that causes loss of voluntary motor control while playing the instrument. A subgroup of patients displays the so-called sensory trick: alteration of somatosensory input, e.g., by wearing a latex glove, may result in short-term improvement of motor control. In this study, the glove-effect in pianists with MD was quantified and its potential association with MD-severity and outcome after treatment was investigated. Thirty affected pianists were included in the study. Music instrument digital interface-based scale analysis was used for assessment of fine motor control. Therapeutic options included botulinum toxin, pedagogical retraining and anticholinergic medication (trihexyphenidyl). 19% of patients showed significant improvement of fine motor control through wearing a glove. After treatment, outcome was significantly better in patients with a significant pre-treatment sensory trick. We conclude that the sensory trick may have a prognostic value for the outcome after treatment in pianists with MD.

Basic Timing Abilities Stay Intact in Patients with Musician's Dystonia

Task-specific focal dystonia is a movement disorder that is characterized by the loss of voluntary motor control in extensively trained movements. Musician's dystonia is a type of task-specific dystonia that is elicited in professional musicians during instrumental playing. The disorder has been associated with deficits in timing. In order to test the hypothesis that basic timing abilities are affected by musician's dystonia, we investigated a group of patients (N = 15) and a matched control group (N = 15) on a battery of sensory and sensorimotor synchronization tasks. Results did not show any deficits in auditory-motor processing for patients relative to controls. Both groups benefited from a pacing sequence that adapted to their timing (in a sensorimotor synchronization task at a stable tempo). In a purely perceptual task, both groups were able to detect a misaligned metronome when it was late rather than early relative to a musical beat. Overall, the results suggest that basic timing abilities stay intact in patients with musician's dystonia. This supports the idea that musician's dystonia is a highly task-specific movement disorder in which patients are mostly impaired in tasks closely related to the demands of actually playing their instrument.

A model of task-specific focal dystonia

Task-specific focal dystonia is a task-specific movement disorder which manifests itself as a loss of voluntary motor control in extensively trained movements. The condition is most frequent in musicians. Until today, the aetiology of focal hand dystonia is not completely understood, but there is growing evidence for an abnormal cortical processing of sensory information, as well as degraded representation of motor functions. It was demonstrated that in the somatosensory cortex the topographical location of sensory inputs from individual fingers is corrupted. Occasionally, a change in sensory information of the hand may at least temporarily improve the condition. This phenomenon is called sensory trick. In this paper, we propose a model of encoding of sensory stimuli which could explain the task specificity of cortical representations of the fingers or other effectors in the context of dystonia. In the framework of this model a sensory stimulus is encoded as a signal vector of higher dimension. A part of its components directly represents the sensory stimulus, while the remaining components describe the context. This model does not only account for the task specificity, but may also explain some characteristics of the retraining process in this disorder.

Long‐term improvement of musician's dystonia after stereotactic ventro‐oral thalamotomy

Musician's dystonia is a task-specific movement disorder that causes twisting or repetitive abnormal finger postures and movements, which tend to occur only while playing musical instruments. Such a movement disorder will probably lead to termination of the careers of affected professional musicians. Most of the currently available treatments have yet to provide consistent and satisfactory results. We present the long-term follow-up results of ventro-oral thalamotomy for 15 patients with musician's dystonia. Between October 2003 and September 2010, 15 patients with medically intractable task-specific focal hand dystonia that occurred only while playing musical instruments underwent ventro-oral thalamotomy. We used Tubiana's musician's dystonia scale to evaluate the patients' pre- and postoperative neurological conditions. All patients except 1 (93%) experienced dramatic improvement of dystonic symptoms immediately after ventro-oral thalamotomy. The mean follow-up period was 30.8 months (range=4-108 months). None of the patients experienced recurrence or deterioration of symptoms during the follow-up periods. Ventro-oral thalamotomy remarkably improved musician's dystonia, and the effect persisted for a long duration.