Focal hand dystonia in musicians: phenomenology, etiology, and psychological trigger factors

An overview of rehabilitation approaches for focal hand dystonia in musicians: A scoping review

OBJECTIVE

To provide a comprehensive overview of rehabilitation treatment strategies for focal hand dystonia (FHD) in musicians, examining their evolution and effectiveness.

DATA SOURCES

A systematic search of five databases, PubMed, PEDro, Cochrane Library, Trip, and Google Scholar, to identify relevant articles on FHD rehabilitation. The last search was performed on 20 December 2023.

METHODS

Inclusion criteria were applied to 190 initially identified articles, resulting in 17 articles for review. Exclusions were made for duplicates, irrelevant titles, abstracts, and non-rehabilitation interventions.

RESULTS

Ten different rehabilitation approaches were identified over 20 years. While no definitive intervention protocol exists, a multimodal approach is commonly recommended.

CONCLUSIONS

This scoping review underscores the diversity of rehabilitation strategies for FHD. It suggests the potential of multimodal approaches, emphasizing the need for further large-scale clinical efficacy studies.

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.

Evaluation of the efficacy and safety of MRI-guided focused ultrasound (MRgFUS) for focal hand dystonia: study protocol for an open-label non-randomised clinical trial

Introduction

MRI-guided focused ultrasound (MRgFUS) thalamotomy provides an exciting development in the field of minimally invasive stereotactic neurosurgery. Current treatment options for focal hand dystonia are limited, with potentially more effective invasive stereotactic interventions, such as deep brain stimulation or lesional therapies, rarely used. The advent of minimally invasive brain lesioning provides a potentially safe and effective treatment approach with a recent pilot study establishing MRgFUS Vo-complex thalamotomy as an effective treatment option for focal hand dystonia. In this study, we undertake an open-label clinical trial to further establish MRgFUS Vo-complex thalamotomy as an effective treatment for focal hand dystonia with greater attention paid to potential motor costs associated with this treatment. To elucidate pathophysiology of dystonia and treatment mechanisms, neurophysiological and MRI analysis will be performed longitudinally to explore the hypothesis that neuroplastic and structural changes that may underlie this treatment benefit.

Methods and analysis

A total of 10 participants will be recruited into this open-label clinical trial. All participants will undergo clinical, kinemetric, neurophysiological and radiological testing at baseline, followed by repeated measures at predesignated time points post MRgFUS Vo-complex thalamotomy. Further, to identify any underlying structural or neurophysiological abnormalities present in individuals with focal hand dystonia, 10 age and gender matched control participants will be recruited to undergo comparative investigation. These results will be compared with the intervention participants both at baseline and at 12 months to assess for normalisation of these abnormalities, if present.

Ethics and dissemination

This trial was reviewed and approved by the St Vincent's Health Network Sydney Human Research Ethics Committee (2022/ETH00778). Study results will be published in peer-reviewed journals and presented at both national and international conferences.

Trial registration number

CTRN12622000775718.

The effects of anxiety on practice behaviors and performance quality in expert pianists

Introduction

During their career, musicians need to undergo intense periods of training to master musical instruments and become accomplished artists. Dysfunctional practice behaviors and anxiety are often mentioned among the possible risk factors for playing-related injuries in musicians. However, the mechanism through which these might lead to the onset of these injuries is still unclear. The present study aims at overcoming this limitation by investigating the relationship between quantitative measurements of anxiety, practice behaviors and music performance quality.

Methods

The experiment consisted in monitoring practice behaviors in 30 pianists practicing a short musical task.

Results

Most self-report anxiety measurements were positively correlated with practice time, especially those collected right before the practice sessions. Similar correlations were identified between anxiety and the number of repetitions of the musical task. Physiological markers of anxiety were only weakly related to practice behaviors. Subsequent analyses showed that high levels of anxiety were associated with poor quality of music performances at baseline. Nevertheless, the interaction between participants’ learning rate and anxiety measures showed no association with performance quality scores. Moreover, anxiety and performance quality co-developed during practice sessions, showing that pianists who improved their playing were also less anxious in the latter part of the experiment.

Discussion

These findings suggest that anxious musicians are likely at higher risk of developing playing-related injuries related to overuse and repetitive strains. Future directions and clinical implications are discussed.

Muscular and kinematic features in speed skaters indicate a task-specific dystonia

OBJECTIVE

Skater's cramp is a movement disorder in speed skaters. We investigated whether affected skaters matched the disease profile of task-specific dystonia, specifically whether there was evidence of maladaptive muscle activity occurring simultaneously with aberrant movements (jerking). We further examined different skating intensities, positing no change would be more indicative of task-specific dystonia.

METHODS

We analyzed video, kinematic and muscle activity in 14 affected skaters. We measured the angular velocity and electromyographic activity of normalized speed skating strokes using one dimensional statistical non-parametric mapping. Skaters were matched with comparably skilled controls, and filled out a bespoke clinical questionnaire.

RESULTS

Skaters' impacted leg showed over-activation in the peroneus longus, tibialis anterior and gastrocnemius that coincided with higher foot movement compared to their healthy leg and controls. This pattern persisted regardless of skating intensity. Clinical features indicated it was task-specific and painless with common trigger factors including stress, equipment change, and falling.

CONCLUSIONS

We showed aberrant muscular and kinematic activity in a movement disorder in speed skaters indicative of task-specific dystonia.

SIGNIFICANCE

Understanding skater's cramp as a task-specific dystonia could reduce the damage that misdiagnosis and unsuccessful invasive operations have caused. Our quantitative method has value in testing future treatment efficacy.

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.

Is Behavioural Therapy a New Treatment Option for Task-Specific Dystonia in Athletes? A Case Series

Background

Task-specific dystonia is a movement disorder of the central nervous system characterized by focal involuntary spasms and muscle contractions, which can negatively affect performance of a specific task. It can affect a wide range of fine motor skills, also in athletes. Current management of task-specific dystonia includes mainly prescribing drugs, exercise therapy or botulinum injections to the affected muscles. Psychological interventions for athletes suffering from task-specific dystonia have not been described extensively so far.

Methods

We present a case-series of 4 different advanced skill-level athletes with suspected task-specific dystonia, which had a major impact on their performance. They all received treatment consisting of a combination of standardized behavioural therapy and relaxation techniques in the form of hypnosis in a total of 8 sessions in a 16-week time period.

Results

After treatment, all athletes returned to their original high level of sport performance without further symptoms of their suspected task-specific dystonia.

Discussion

Behavioural therapy in combination with a relaxation technique seems to be a safe and promising treatment for athletes with suspected task-specific dystonia. Further studies in a larger, preferably randomized controlled trial, are warranted to evaluate if this treatment strategy is effective in athletes with suspected task-specific dystonia.

Focal Dystonia and the Stress Network: The Role of Stress Vulnerability and Adverse Childhood Experiences in the Development of Musician's Dystonia

Musician's dystonia is often described as a neurological disorder, resulting from reduced inhibition in the basal ganglia and the cerebellum and dysfunctional cortical plasticity. However, several studies over the last decades support the hypothesis that psychological factors play an important role in the aetiology of dystonia, contradicting its classification as "purely neurological". Especially adverse childhood experiences (ACEs) such as neglect, maltreatment, or household dysfunction may influence the sensorimotor system, additionally to the impact they have on psychological traits. They are known to alter limbic networks, such as the amygdala, the hippocampus, and the stress response via the hypothalamus-pituitary-adrenal (HPA) axis and might also affect the cortico-striatal-thalamo-cortical loop that is vital for correct motor movement learning. Especially a higher activity of the basolateral amygdala could be important by increasing the consolidation of dysfunctional motor memories in stressful situations.Therefore, this chapter explores how musician's dystonia might be a result of dysfunctional stress-coping mechanisms, additionally to the already established neurological alterations.

Failure of motor function-A Developmental Embodiment Research perspective on the systemic effects of stress

Humans are capable to skillfully perform a huge variety of complex movements seemingly effortless and to flexibly adjust movement execution to ever-changing environmental conditions, often without apparent differences in the movement outcome. This impressive ability has sparked scientific interest in the mechanisms underlying movement execution for decades. In this perspective article, we argue that investigating the processes and mechanisms leading to failure of motor functions is a fruitful approach to advance the field of human motor neuroscience and beyond. The study of failure of motor function in specific populations (patient groups, skilled experts) has already provided tremendous insight in the systemic characteristics and multi-level functional dependencies of movement execution. However, particularly the transient failure of function in everyday motor actions remains a blind spot. Coming from the perspective of Developmental Embodiment Research, we argue that the integration of a developmental embodiment and lifespan perspective with existing systemic and multi-level methodological approaches of failure of function analyses provides an integrative, interdisciplinary framework, which will allow us to overcome this shortcoming. We further suggest that stress-induced failure of motor function situations might represent a promising starting point for this endeavor. Identifying the involved cross-level functional dependencies of acute and chronic stress on transient and persistent motor functioning would further advance our knowledge on the mechanisms underlying movement execution, and would allow to identify targets for intervention and prevention across the whole spectrum of motor function and failure.

Task-specific dystonia in hairdressers: a questionnaire survey and review of the literature

Hairdresser dystonia is one of the occupational dystonias and task-specific movement disorders occurring as a result of long-term repetitive cutting with scissors. The task-specific dystonia manifests itself as a loss of voluntary motor control during extensive practice of cutting requiring a high level of technical proficiency. The prevalence rate of hairdresser dystonia is not well-known worldwide. A questionnaire regarding dystonia was prepared for hairdressers. After sending the questionnaires to 800 hairdressers by direct mail, 134 answers were received by mail. Five of the 134 were suspected to have hairdresser-associated focal dystonia. Thus, 3.7% of hairdressers might have task-specific dystonia. This report was limited because of the small number of participants. However, this research is valuable because it was difficult to find a patient with suspected dystonia due to concerns related to job security.

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.

Highlights

We 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.

Difference in Personality Traits and Symptom Intensity According to the Trigger-Based Classification of Throwing Yips in Baseball Players

The triggers of initial onset of yips symptoms can be broadly divided into psychological and non-psychological factors; however, a trigger-based classification of yips has not been established. This study aims to obtain insight into the prevention of yips by clarifying whether there are differences in symptoms and personality traits according to a trigger-based classification of yips in baseball players. A total of 107 college baseball players responded to a questionnaire assessing the presence or absence of yips and its symptoms. They were classified into the psychologically triggered yips group, the non-psychologically triggered yips group, and the non-yips group based on the presence or absence of yips and the triggers of its initial onset. Additionally, we compared whether personality traits examined by the NEO Five-Factor Inventory differed across these three groups. The psychologically triggered yips group had significantly higher agreeableness scores compared with the non-yips group, whereas the non-psychologically triggered yips group had significantly higher neuroticism scores compared with the psychologically triggered yips group. In the non-psychologically triggered yips group, there was a significantly higher frequency of throwing errors than in the psychologically triggered yips group, with a tendency to develop yips symptoms gradually. Since the trigger-based classification of yips is closely related to the strength of the yips symptoms and the players' personality traits, the results of this study contribute to a better understanding of the symptoms of yips and establishment of the prevention of yips. Large prospective studies are necessary to determine the causal relationship between a trigger-based classification of yips and the personality traits and symptoms of athletes with yips.

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.

Specialized Somatosensory-Motor Integration Functions in Musicians

Somatosensory signals play roles in the fine control of dexterous movements through a somatosensory-motor integration mechanism. While skilled individuals are typically characterized by fine-tuned somatosensory functions and dexterous motor skills, it remains unknown whether and in what manner their bridging mechanism, the tactile-motor and proprioceptive-motor integration functions, plastically changes through extensive sensorimotor experiences. Here, we addressed this issue by comparing physiological indices of these functions between pianists and nonmusicians. Both tactile and proprioceptive stimuli to the right index finger inhibited corticospinal excitability measured by a transcranial magnetic stimulation method. However, the tactile and proprioceptive stimuli exerted weaker and stronger inhibitory effects, respectively, on corticospinal excitability in pianists than in nonmusicians. The results of the electroencephalogram measurements revealed no significant group difference in the amplitude of cortical responses to the somatosensory stimuli around the motor and somatosensory cortices, suggesting that the group difference in the inhibitory effects reflects neuroplastic adaptation of the somatosensory-motor integration functions in pianists. Penalized regression analyses further revealed an association between these integration functions and motor performance in the pianists, suggesting that extensive piano practice reorganizes somatosensory-motor integration functions so as to enable fine control of dexterous finger movements during piano performances.

Cerebellar 5HT-2A receptor mediates stress-induced onset of dystonia

Stress is a key risk factor for dystonia, a debilitating motor disorder characterized by cocontractions of muscles leading to abnormal body posture. While the serotonin (5HT) system is known to control emotional responses to stress, its role in dystonia remains unclear. Here, we reveal that 5HT neurons in the dorsal raphe nuclei (DRN) send projections to the fastigial deep cerebellar nuclei (fDCN) and that photostimulation of 5HT-fDCN induces dystonia in wild-type mice. Moreover, we report that photoinhibition of 5HT-fDCN reduces dystonia in a1A ^tot/tot mice, a genetic model of stress-induced dystonia, and administration of a 5HT-2A receptor inverse agonist (MDL100907; 0.1 to 1 mg/kg) or shRNA-mediated knockdown of the ht2ar gene in fDCN can notably reduce the onset of dystonia in a1A ^tot/tot mice. These results support the serotonin theory of dystonia and suggest strategies for alleviating symptoms in human patients by blocking 5HT-2A receptors.

Personality Predictors of Yips and Choking Susceptibility

The ability to perform under heightened levels of pressures is one of the largest discriminators of those who achieve success in competition and those who do not. There are several phenomena associated with breakdowns in an athlete's performance in a high-pressure environment, collectively known as paradoxical performances. The two most prevalent and researched forms of paradoxical performance are the yips and choking. The aim of the current study is to investigate a range of psychological traits (fear of negative evaluation, individual differences, anxiety sensitivity, self-consciousness, perfectionistic self-presentation, and perfectionism) and their ability to predict susceptibility to choking and the yips in an experienced athlete sample. 155 athletes (Golfers n = 86; Archers n = 69) completed six trait measures and a self-report measure of yips or choking experience. The prevalence rate for choking and yips in both archers and golfers was 67.7 and 39.4%, respectively. A 2 × 2 × 2 MANOVA and discriminant function analysis revealed that a combination of 11 variables correctly classified 71% of choking and non-choking participants. Furthermore, analysis confirmed that a combination of four variables correctly classified 69% of the yips and non-yips affected participants. In this first study to examine both paradoxical performances simultaneously, these findings revealed that for the yips, all predictors stemmed from social sources (i.e., perfectionistic self-presentation), whereas choking was associated with anxiety and perfectionism, as well as social traits. This important distinction identified here should now be tested to understand the role of these traits as development or consequential factors of choking and the yips.

[Personality traits of Japanese patients with focal dystonia-Variable classification by affected body part and occupation]

We administered the Revised Neo Personality Inventory (NEO-PI-R) to 92 Japanese patients with focal dystonia and analyzed the relation of their personality traits, affected body parts, and occupations using a decision tree method. Results show that participants' personality traits were related to their occupation rather than the body part. Occupational dystonia patients including musicians exhibited neurotic tendencies and a high level of anxiety. Moreover, patients with occupational upper limb dystonia had realistic thinking patterns. Patients with musicians' dystonia were open about their emotional experiences: both positive and negative.

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.

Psychodiagnostics: Classification of the Yips Phenomenon based on Musician's Dystonia

PURPOSE

Similar to musician's focal dystonia, a task-specific phenomenon known as yips, has also been reported in professional athletes. Yips is usually described as focal dystonia, or choking under pressure, or as lying on a continuum between both. Based on the common occupational conditions across musicians and athletes, the present exploratory study aimed to investigate whether musicians diagnosed with focal dystonia and golfers affected with yips, can be similarly subclassified based on their psychological profiles.

METHODS

Twenty healthy musicians, 20 musicians with focal dystonia, 20 healthy golfers, and 20 yips-affected golfers went through a test battery including three psycho-diagnostic standardized questionnaires (the Competitive Trait Anxiety Inventory, the Frost's Multidimensional Perfectionism Scale, and the Stress Coping Questionnaire), measuring trait cognitive and somatic anxiety, perfectionistic tendencies and different stress coping strategies.

RESULTS

Findings based on a clustering procedure suggest that similar to musician's dystonia, yips-affected golfers can be classified into those with and those without specific elevated perfectionistic, stress and anxiety traits. The roles of these different psychological profiles as possible triggering factors of the yips are discussed and compared with those of musician's dystonia.

CONCLUSIONS

The current study suggests that the yips phenomenon might cover a broader range of different subtypes of movement disturbances than those already suggested in the literature. Finally, a theoretical model, which explains the role of the different triggering factors in the discrimination of the different subtypes, is suggested. A better classification and understanding of the different subtypes of yips could lead to a more accurate diagnosis and to the design of more individualized treatment intervention.

Sensory–motor rehabilitation therapy for task-specific focal hand dystonia: A feasibility study

Introduction

Medical treatments have limited long-term effect in task-specific dystonia. Whilst evidence supports the use of rehabilitation, no randomised controlled trials have been undertaken. This small-scale study determined the feasibility of implementing and evaluating a mixed sensory–motor task-specific dystonia rehabilitative programme.

Methods

Participants with writer’s or musician’s dystonia were recruited from a movement disorder and hand therapy clinic. Feasibility measures were recruitment rate, retention, session attendance, adherence to exercises. Self-report measures at 0, 3 and 6 months included: Arm Dystonia Disability Scale (ADDS), Tubiana and Chamagne Scale (TCS), Brief Illness Perception Questionnaire (BIPQ), Health Status (EQ-5D 5L), Clinical Global Impression Scale (CGI). Task performance was video-recorded at baseline and 6 months. At 6 months, interviews explored participant experiences of the intervention.

Results

Fifteen patients were recruited over 6 months (rate 2.5/month, musician’s dystonia = 8, writer’s dystonia = 7). Complete data sets were collected for twelve people(80%). The programme comprised a maximum six sessions plus daily home exercises. Nine completed the home programme at ≥75%. No adverse events were reported. Effect sizes at 3 and 6 months, respectively, were ADDS 3-month = 0.28, 6-month = 0.23; TCS 3-month = 0.13, 6-month = 0.53; BIPQ 3-month = 0.38, 6-month = 0.71; EQ-5D-5L 3-month = 0.34, 6-month = 0.59; video analysis at 6 months = 0.78. Eleven (92%) improved on the CGI. Interviews supported acceptability of the intervention.

Conclusions

This intervention was feasible to deliver with high retention, adherence and acceptability. Improvements occurred across measures. This informs the development of future randomised controlled trials.

A unifying motor control framework for task-specific dystonia

Task-specific dystonia is a movement disorder characterized by a painless loss of dexterity specific to a particular motor skill. This disorder is prevalent among writers, musicians, dancers and athletes. No current treatment is predictably effective, and the disorder generally ends the careers of affected individuals. Traditional disease models of dystonia have a number of limitations with regard to task-specific dystonia. We therefore discuss emerging evidence that the disorder has its origins within normal compensatory mechanisms of a healthy motor system in which the representation and reproduction of motor skill are disrupted. We describe how risk factors for task-specific dystonia can be stratified and translated into mechanisms of dysfunctional motor control. The proposed model aims to define new directions for experimental research and stimulate therapeutic advances for this highly disabling disorder.

Clinical and Phenomenological Characteristics of Patients with Task-Specific Lingual Dystonia: Possible Association with Occupation

BACKGROUND

Lingual dystonia is a subtype of oromandibular dystonia, which is a movement disorder characterized by involuntary sustained or intermittent contraction of the masticatory and/or tongue muscles. Lingual dystonia interferes with important daily activities, such as speaking, chewing, and swallowing, resulting in vocational and social disability.

OBJECTIVE

The aim of this study was to investigate a possible relationship between occupation and the development of lingual dystonia.

METHODS

Phenomenological and clinical characteristics of 95 patients [53 females (55.8%) and 42 males (44.2%), mean age 48.0 years] with task-specific, speech-induced lingual dystonia were analyzed. Structured interviews were carried out to obtain information regarding primary occupation, including overtime work and stress during work. The factors that might have influenced the development of lingual dystonia were estimated using multivariate logistic regression analysis of the 95 patients with lingual dystonia and 95 controls [68 females (71.6%) and 27 males (28.4%), mean age 47.2 years] with temporomandibular disorders.

RESULTS

Overall, 84.2% of the patients had regular occupations; 73.8% of the patients with regular occupations reported working overtime more than twice a week, and 63.8% of them experienced stress at the workplace. Furthermore, 82.1% of the patients had engaged in occupations that required them to talk to customers or other people under stressful situations over prolonged periods of time for many years (mean: 15.6 years). The most common occupation was sales representative (17.9%), followed by telephone operator (13.7%), customer service representative (10.5%), health care worker (9.5%), waiter or waitress (5.3%), receptionist (5.3%), and cashier (5.3%). Twenty-nine patients (30.5%) had tardive lingual dystonia. Logistic regression analyses revealed that frequent requirements for professional speaking (p = 0.011, odds ratio: 5.66), high stress during work (p = 0.043, odds ratio: 5.4), and neuroleptic use (p = 0.032, odds ratio: 2.52) were significant contributors to the manifestation of lingual dystonia.

CONCLUSION

Professions in which conversations in stressful situations are unavoidable may trigger lingual dystonia. Therefore, speech-induced lingual dystonia can be regarded as occupational dystonia in certain cases.

Fit to Perform: An Investigation of Higher Education Music Students' Perceptions, Attitudes, and Behaviors toward Health

Making music at the highest international standards can be rewarding, but it is also challenging, with research highlighting pernicious ways in which practicing and performing can affect performers' health and wellbeing. Several studies indicate that music students' perceptions, attitudes, and behaviors toward health and healthy living are less than optimal, especially considering the multiple physical and psychological demands of their day-to-day work. This article presents the results of a comprehensive screening protocol that investigated lifestyle and health-related attitudes and behaviors among 483 undergraduate and postgraduate students (mean age = 21.29 years ± 3.64; 59% women) from ten conservatoires. The protocol included questionnaires measuring wellbeing, general health, health-promoting behaviors, perfectionism, coping, sleep quality, and fatigue. On each measure, the data were compared with existing published data from similar age groups. The results indicate that music students have higher levels of wellbeing and lower fatigue than comparable samples outside of music. However, they also reveal potentially harmful perceptions, attitudes, and behaviors toward health. Specifically, engagement in health responsibility and stress management was low, which along with high perfectionistic strivings, limited use of coping strategies, poor sleep quality, and low self-rated health, paints a troubling picture both for the music students and for those who support their training. The findings point to the need for more (and more effective) health education and promotion initiatives within music education; in particular, musicians should be better equipped with mental skills to cope with constant pressure to excel and high stress levels. In part, this calls for musicians themselves to engage in healthier lifestyles, take greater responsibility for their own health, and be aware of and act upon health information in order to achieve and sustain successful practice and performance. For that to happen, however, music educators, administrators, and policy makers must play an active role in providing supportive environments where health and wellbeing is considered integral to expert music training.

Occupational Health and the Performing Arts: An Introduction

OBJECTIVE

Workplace hazards in the performing arts cause injuries, disabilities, and deaths every year. Occupational health professionals are familiar with most of these hazards and are particularly qualified to contribute to efforts to reduce them. This article reviews current health issues in the performing arts and highlights opportunities for occupational health contributions.

METHODS

Recognized experts in performing arts medicine were consulted and articles illustrating performing arts health issues were reviewed. Literature sources included medical databases, unindexed art-health publications, and popular press articles.

RESULTS

Resources discussing hazards and health issues in theater, dance, voice, and instrumental musicians were located and reviewed.

CONCLUSIONS

Treatment providers have a history of involvement with segments of the performing arts. The occupational health approach to workplace health issues can effectively complement these efforts. Sources of further information on performing arts health concerns are available.

Clinical and Epidemiological Correlates of Task-Specific Dystonia in a Large Cohort of Brazilian Music Players

Musician’s dystonia is a task-specific dystonia (TSD) worldwide disabling disorder, and most of the affected individuals may have severe difficulty to play their instrument. Many professional music players may have to quit working as a player. The objective of the present study was to evaluate the clinical characteristics and frequency of TSD in Brazilian music players and to promote awareness of this condition among musicians. We visited orchestras and music schools delivering lectures on TSD and about the scope of our survey. Musicians were invited to answer a questionnaire, and those with possible neurological dysfunction associated with musical performance were recorded by video while playing the instrument. We visited 51 orchestras and music schools in 19 Brazilian cities between March 2013 and March 2015. We collected 2,232 questionnaires, and 72 subjects with suspicion of dystonia were video recorded during specific tasks and evaluated regarding motor impairment. Forty-nine individuals (2.2%) were diagnosed as having TSD (mean age 36.4 years; 92% male). The instruments most associated with TSD were acoustic guitar (36.7%) and brass instruments (30.6%). We concluded that Brazilian TSD music players are mainly male, classical music professionals, around 30 years of age, with arms, hands, or oromandibular muscles affected. TSD is a neurological condition that can impair musical performance and should receive more attention from musicians, teachers, and health professionals.

Objective Evaluation of Performance Stress in Musicians With Focal Hand Dystonia: A Case Series

Five musicians suffering from focal dystonia participated in a pilot study that examined the feasibility of an experimental protocol designed to assess musicians' motor performance under stress. Electrocardiography, free cortisol levels, and subjective assessments were used to monitor alterations of the hypothalamic-pituitary-adrenal axis. As measures of motor outcome, temporal variability of finger movements and muscular cocontraction of the wrist flexor and extensor were assessed. Findings suggest that the specific experimental design could be successfully applied. Several methodological issues such as carryover effects, the use of free cortisol, the inclusion of a double baseline, and the classification of dystonic patients into stress responders and nonresponders are analyzed and discussed.

Task-specific dystonia: pathophysiology and management

Task-specific dystonia is a form of isolated focal dystonia with the peculiarity of being displayed only during performance of a specific skilled motor task. This distinctive feature makes task-specific dystonia a particularly mysterious and fascinating neurological condition. In this review, we cover phenomenology and its increasingly broad-spectrum risk factors for the disease, critically review pathophysiological theories and evaluate current therapeutic options. We conclude by highlighting the unique features of task-specific dystonia within the wider concept of dystonia. We emphasise the central contribution of environmental risk factors, and propose a model by which these triggers may impact on the motor control of skilled movement. By viewing task-specific dystonia through this new lens which considers the disorder a modifiable disorder of motor control, we are optimistic that research will yield novel therapeutic avenues for this highly motivated group of patients.

Maladaptive Plasticity Induces Degradation of Fine Motor Skills in Musicians

Abstract. Performing music at a professional level is probably one of the most complex human accomplishments requiring extensive training periods. The superior skills of musicians are mirrored in plastic adaptations of the brain involving gray and white matter increase in sensory motor and auditory areas and enlargement of receptive fields. Motor disturbances in musicians are common and include mild forms, such as temporary motor fatigue, painful overuse injuries following prolonged practice, anxiety-related motor failures during performances, and more persistent losses of motor control, termed “dynamic stereotypes.” Musician’s dystonia is characterized by a permanent loss of motor control when playing a musical instrument linked to genetic susceptibility and to maladaptive plasticity. In this review article, we argue that these motor failures developing on a continuum from motor fatigue to musician’s dystonia require client tailored treatment and accordingly specific psychological and neurological interventions.

The curse of motor expertise: Use-dependent focal dystonia as a manifestation of maladaptive changes in body representation

Focal task-specific dystonia (FTSD) impairs not only motor dexterity, but also somatosensory perception involved in well-trained behavioral tasks. Occupations that carry a risk of developing FTSD include musician, writer, painter, surgeon, and golfer, which are characterized by repetitive and precise motor actions over a prolonged period. Behavioral studies have uncovered various undesirable effects of FTSD on sensorimotor functions, such as a loss of independent movement control, unintended muscular co-activation, awkward limb posture, and impairment of fine discrimination of tactile and proprioceptive sensations. Studies using neuroimaging and noninvasive brain stimulation techniques have related such sensorimotor malfunctions to maladaptive neuroplastic changes in the sensorimotor system, including the primary motor and somatosensory areas, premotor area, cerebellum, and basal ganglia. In this review, we summarize recent empirical findings regarding phenomenological and pathophysiological abnormalities associated with the development of FTSD. We particularly focused on maladaptive alterations of body representations underlying the degradation of fine motor control and somatosensory perception in FTSD patients.

Acquisition and reacquisition of motor coordination in musicians

Precise control of movement timing plays a key role in musical performance. This motor skill requires coordination across multiple joints and muscles, which is acquired through extensive musical training from childhood. However, extensive training has a potential risk of causing neurological disorders that impair fine motor control, such as task-specific tremor and focal dystonia. Recent technological advances in measurement and analysis of biological data, as well as noninvasive manipulation of neuronal activities, have promoted the understanding of computational and neurophysiological mechanisms underlying acquisition, loss, and reacquisition of dexterous movements through musical practice and rehabilitation. This paper aims to provide an overview of the behavioral and neurophysiological basis of motor virtuosity and disorder in musicians, representative extremes of human motor skill. We also report novel evidence of effects of noninvasive neurorehabilitation that combined transcranial direct-current stimulation and motor rehabilitation over multiple days on musician's dystonia, which offers a promising therapeutic means.

Apollo's curse: neurological causes of motor impairments in musicians

Performing music at a professional level is probably one of the most complex human accomplishments. Extremely fast and complex, temporo-spatially predefined movement patterns have to be learned, memorized, and retrieved with high reliability in order to meet the expectations of listeners. Performing music requires not only the integration of multimodal sensory and motor information, and its precise monitoring via auditory and kinesthetic feedback, but also emotional communicative skills, which provide a "speaking" rendition of a musical masterpiece. To acquire these specialized auditory-sensory-motor and emotional skills, musicians must undergo extensive training periods over many years, which start in early childhood and continue on through stages of increasing physical and strategic complexities. Performance anxiety, linked to high societal pressures such as the fear of failure and heightened self-demands, frequently accompanies these learning processes. Motor disturbances in musicians are common and include mild forms, such as temporary motor fatigue with short-term reduction of motor skills, painful overuse injuries following prolonged practice, anxiety-related motor failures during performances (choking under pressure), as well as more persistent losses of motor control, here termed "dynamic stereotypes" (DSs). Musician's dystonia (MD), which is characterized by the permanent loss of control of highly skilled movements when playing a musical instrument, is the gravest manifestation of dysfunctional motor programs, frequently linked to a genetic susceptibility to develop such motor disturbances. In this review chapter, we focus on different types of motor failures in musicians. We argue that motor failures in musicians develop along a continuum, starting with subtle transient degradations due to fatigue, overuse, or performance stress, which transform by and by into more permanent, still fluctuating motor degradations, the DSs, until a more irreversible condition, MD manifests. We will review the epidemiology and the principles of medical treatment of MD and discuss prevention strategies.

Are movement disorders and sensorimotor injuries pathologic synergies? When normal multi-joint movement synergies become pathologic

The intact nervous system has an exquisite ability to modulate the activity of multiple muscles acting at one or more joints to produce an enormous range of actions. Seemingly simple tasks, such as reaching for an object or walking, in fact rely on very complex spatial and temporal patterns of muscle activations. Neurological disorders such as stroke and focal dystonia affect the ability to coordinate multi-joint movements. This article reviews the state of the art of research of muscle synergies in the intact and damaged nervous system, their implications for recovery and rehabilitation, and proposes avenues for research aimed at restoring the nervous system’s ability to control movement.

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.

We Are Able, We Intend, We Act—But We Do Not Succeed: A Theoretical Framework for a Better Understanding of Paradoxical Performance in Sports

Paradoxical performance can be described simply as a sudden decrease in a top athlete’s performance despite the athlete’s having striven for superior performance, such as the lost-skill syndrome in trampolining or “the yips” in golf. There is a growing amount of research on these phenomena, which resemble movement disorders. What appears to be missing, however, is a clear phenomenology of the affected movement characteristics leading to a classification of the underlying cause. This understanding may enable specific diagnostic methods and appropriate interventions. We first review the different phenomena, providing an overview of their characteristics and their occurrence in sports and describing the affected sports and movements. We then analyze explanations for the yips, the most prominent phenomenon, and review the methodological approaches for diagnosing and treating it. Finally, we present and elaborate an action theoretical approach for diagnosing paradoxical performance and applying appropriate interventions.

[Focal dystonia in musicians: Phenomenology and musical triggering factors]

Dystonias are defined as a joint sustained and involuntary contraction of agonist and antagonist muscles, which can cause torsion, repetitive abnormal involuntary movements, and/or abnormal postures. One special group of dystonias are those known as occupational, which include dystonia disorders triggered by a repetitive motor activity associated with a specific professional activity or task. Musicians are a population particularly vulnerable to these types of dystonia, which are presented as a loss of coordination and voluntary motor control movements highly trained in musical interpretation. Our aim is to describe a clinical series of focal dystonias in musicians evaluated and treated in our centre.

PATIENTS AND METHODS

Data is presented on a clinical series of 12 musicians with occupational dystonia. Their history and phenomenology are described, as well as well as their outcome after therapy.

RESULTS

Demographic details: Mean age 34.8 ± 11.8 years, 10 males (83.3%) and 2 females (16.7%).

CLINICAL HISTORY

History of trauma in dystonic segment, 6 patients (50%); family history of neurological diseases in first-degree relatives, 6 patients (50%); occupational history according to music category, 8 patients (66.6%) were classical musicians and 4 patients (33.3%) were popular musicians.

PHENOMENOLOGY

The dystonia syndrome was characterised by having a mean age of onset of 28.2 ± 11.3 years (range 18-57 years). The segment affected was the hand (91.7%) in 11 patients. Of all the musicians seen in the clinic, 9 of them (75%) received therapy. The majority of patients appeared to have triggering factors specific to musical execution and linked to the requirement of fine motor control. It should be mentioned that 50% of the musicians treated maintained their professional activity or position in the orchestra to which they belonged.

CONCLUSIONS

The majority of our phenomenological findings are consistent with those reported in the current literature. However, it is worth mentioning the presence of triggering factors attributed to the specific requirements of performing music, linked to the participation of fine motor control.

Playing beautifully when you have to be fast: spatial and temporal symmetries of movement patterns in skilled piano performance at different tempi

Humans are capable of learning a variety of motor skills such as playing the piano. Performance of these skills is subject to multiple constraints, such as musical phrasing or speed requirements, and these constraints vary from one context to another. In order to understand how the brain controls highly skilled movements, we investigated pianists playing musical scales with their left or right hand at various speeds. Pianists showed systematic temporal deviations away from regularity. At slow tempi, pianists slowed down at the beginning and end of the movement (which we call phrasal template). At fast tempi, temporal deviation traces consisted of three peak delays caused by a thumb-under manoeuvre (which we call neuromuscular template). Intermediate tempi were a linear combination trade-off between these two. We introduce and cross-validate a simple four-parameter model that predicted the timing deviation of each individual note across tempi (R(2) = 0.70). The model can be fitted on the data of individual pianists, providing a novel quantification of expert performance. The present study shows that the motor system can generate complex movements through a dynamic combination of simple movement templates. This provides insight into how the motor system flexibly adapts to varying contextual constraints.

Psychological characteristics in musician׳s dystonia: a new diagnostic classification

Numerous studies suggest that dysfunctional basal ganglia-thalamo-cortical circuits are involved in both movement disorders and psychiatric impairments. The current exploratory investigation explored possible psychological differences, firstly between 24 healthy musicians (HM) and 24 musicians diagnosed with focal dystonia (FDM) (Study I), and secondly among 35 FDM patients only (Study II). Results revealed that FDM patients are six times more likely to exhibit elevated anxiety, perfectionistic and stress characteristics than HM. These psychological conditions might contribute as aggravating risk factors to the development of FDM. However, half of the FDM patients did not demonstrate any signs of anxiety, perfectionism or stress. The findings point to the clear existence of two different psychological profiles among FDM patients. We suggest that this psychological distinction might reflect two different mal-adaptive processes mediated via different circuits of the cortico-basal ganglia-thalamicloops. The new classification of FDM patients will contribute to the reinforcement of the diagnostic repertoire, necessary for the selection of more specific treatment methods.

Psychiatric comorbidities in dystonia: emerging concepts

Psychiatric disorders are highly prevalent in patients with dystonia and have a profound effect on quality of life. Patients with dystonia frequently meet criteria for anxiety disorders, especially social phobia, and major depressive disorder. Deficits in emotional processing have also been demonstrated in some dystonia populations. Onset of psychiatric disturbances in patients with dystonia often precedes onset of motor symptoms, suggesting that the pathophysiology of dystonia itself contributes to the genesis of psychiatric disturbances. This article examines the hypothesis that mood and anxiety disorders are intrinsic to the neurobiology of dystonia, citing the available literature, which is derived mostly from research on focal isolated dystonias. Limitations of studies are identified, and the role of emotional reactivity, especially in the context of pain secondary to dystonia, is recognized. Available evidence underscores the need to develop dystonia assessment tools that incorporate psychiatric measures. Such tools would allow for a better understanding of the full spectrum of dystonia presentations and facilitate research on the treatment of dystonia as well as the treatment of psychiatric illnesses in the context of dystonia. This article, solicited for a special Movement Disorders issue on novel research findings and emerging concepts in dystonia, addresses the following issues: (1) To what extent are psychiatric disturbances related to the pathophysiology of dystonia? (2) What is the impact of psychiatric disturbances on outcome measures of current assessment tools for dystonia? (3) How do psychiatric comorbidities influence the treatment of dystonia? Answers to these questions will lead to an increased appreciation of psychiatric disorders in dystonia, a better understanding of brain physiology, more nuanced research questions pertaining to this population, better clinical scales that can be used to further patient management and research, and improved patient outcomes. © 2013 Movement Disorder Society.

How to detect the yips in golf

The yips is a multi-aetiological phenomenon that is characterized by an involuntary movement that can affect a golfer's putting performance. Diagnostics are crucial for a better understanding of what causes the yips but are still lacking. The purpose of the present study was therefore to identify sensitive methods for detecting the yips and evaluating its aetiology. Forty participants, 20 yips-affected golfers and 20 nonaffected golfers, completed a psychometric testing battery and performed a putting session in the laboratory. They answered questions about their golfing and yips experience and filled in standardized questionnaires measuring trait anxiety, perfectionism, stress-coping strategies, somatic complaints, and movement and decision reinvestment. In the laboratory, they had to putt in five different conditions that might elicit the yips: as usual with both arms, under pressure, with one (the dominant) arm, with a unihockey racket, and with latex gloves. Measures included putting performance, situational anxiety, kinematic parameters of the putter, electromyography of the arm muscles, and electrocardiography. The groups were separated only by putting performance and kinematic parameters when putting with the dominant arm. Future research should use kinematics to investigate the aetiology of the yips and possible interventions.