Combinación de tres técnicas en el reentrenamiento de un músico con distonía focal: estudio de un caso / The use of three combined techniques in the retraining of a mucisian with focal dystonia: a case study

La distonía resulta de una co-contracción sostenida de músculos agonistas y antagonistas que puede causar torsión, movimientos involuntarios o posturas anormales que interfieren con el control voluntario de la mano, u otro grupo muscular, involucrados en una determinada acción; por ejemplo, tocar un instrumento, o escribir.El presente estudio descriptivo, de caso único, buscó probar la efectividad de un tratamiento que combinó tres técnicas (técnica del umbral, imaginería, y relajación por neurofeedback) en el reentrenamiento de un concertista profesional con distonía focal. Según evaluación por jueces, los resultados después de dos semanas de tratamiento, no fueron concluyentes. Sin embargo, el reporte experiencial del propio músico dio cuenta de una clara mejoría. Ante la carencia de un método efectivo para larehabilitación demúsicos con distonía focal, la relevancia del presente estudio consistió en identificar y combinar técnicas específicas que pueden contribuir a ese propósito. En estudios futuros, sería de interés probar el efecto del mismo tratamiento,pero más prolongado; o el efecto de la incorporación de las técnicas en sucesión progresiva, iniciando siempre con la relajación por neurofeedback.

Focal dystonia results from a sustained simultaneous co-contraction of agonists and antagonists muscle fibers which can cause twisting, involuntary movements or abnormal postures that interfere with voluntary control of the hand, arm, mouth, or other muscle groups involved in a given action; for example, playing an instrument, or hand writing. This descriptive, single case study, sought to explore the effectiveness of a treatment that combined three procedures: the threshold technique, imagery, and neurofeedback induced relaxation, in retraining of a professional cello player with focal dystonia. After two weeks of treatment, experts judged the results inconclusive; however, the report from the actual patient accounted for a note worthy recovery over time. In the absence of an effective method to rehabilitate musicians with focal dystonia, the relevance of this study resided on thepossibility of identifying and combining specific techniques that could be effective. Future studies might want to explore these same or different techniques, but perhaps for a longer period of time.

A multifactorial conceptual model of peripheral neuromusculoskeletal predisposing factors in task-specific focal hand dystonia in musicians: etiologic and therapeutic implications.

A model is presented showing how peripheral factors may cause a process of movement adaptation that leads to task-specific focal hand dystonia in musicians (FHDM). To acquire a playing technique, the hand must find effective and physiologically sustainable movements within a complex set of functional demands and anatomic, ergonomic, and physiological constraints. In doing so, individually discriminating constraints may become effective, such as limited anatomic independence of finger muscles/tendons, limited joint ranges of motion, or (subclinical) neuromusculoskeletal defects. These factors may, depending on the instrument-specific playing requirements, compromise or exclude functional playing movements. The controller (i.e., the brain) then needs to develop alternative motions to execute the task, which is called compensation. We hypothesize that, if this compensation process does not converge to physiologically sustainable muscle activation patterns that satisfy all constraints, compensation could increase indefinitely under the pressure of practice. Dystonic symptoms would become manifest when overcompensation occurs, resulting in motor patterns that fail in proper task execution. The model presented in this paper only concerns the compensatory processes preceding such overcompensations and does not aim to explain the nature of the dystonic motions themselves. While the model considers normal learning processes in the development of compensations, neurological predispositions could facilitate developing overcompensations or further abnormal motor programs. The model predicts that if peripheral factors are involved, FHDM symptoms would be preceded by long-term gradual changes in playing movements, which could be validated by prospective studies. Furthermore, the model implies that treatment success might be enhanced by addressing the conflict between peripheral factors and playing tasks before decompensating/retraining the affected movements.

Functional recovery from chronic writer's cramp by brain-computer interface rehabilitation: a case report.

BACKGROUND: Dystonia is often currently treated with botulinum toxin injections to spastic muscles, or deep brain stimulation to the basal ganglia. In addition to these pharmacological or neurosurgical measures, a new noninvasive treatment concept, functional modulation using a brain-computer interface, was tested for feasibility. We recorded electroencephalograms (EEGs) over the bilateral sensorimotor cortex from a patient suffering from chronic writer's cramp. The patient was asked to suppress an exaggerated beta frequency component in the EEG during hand extension. RESULTS: The patient completed biweekly one-hour training for 5 months without any adverse effects. Significant decrease of the beta frequency component during handwriting was confirmed, and was associated with clear functional improvement. CONCLUSION: The current pilot study suggests that a brain-computer Interface can give explicit feedback of ongoing cortical excitability to patients with dystonia and allow them to suppress exaggerated neural activity, resulting in functional recovery.

Utility of multi-channel surface electromyography in assessment of focal hand dystonia.

INTRODUCTION: Surface electromyography (SEMG) allows objective assessment and guides selection of appropriate treatment in focal hand dystonia (FHD). METHODS: Sixteen-channel SEMG obtained during different phases of a writing task was used to study timing, activation patterns, and spread of muscle contractions in FHD compared with normal controls. Customized software was developed to acquire and analyze EMG signals. RESULTS: SEMG of FHD subjects (20) showed "early onset" during motor imagery, rapid proximal muscle recruitment, agonist-antagonist co-contraction involving proximal muscle groups, "delayed offset" after stopping writing, higher rectified mean amplitudes, and mirror activity in contralateral limb compared with controls (16). Muscle activation latencies were heterogenous in FHD. CONCLUSIONS: Anticipation, delayed relaxation, and mirror EMG activation were noted in FHD. A clear pattern of muscle activation cannot be ascertained. Multi-channel SEMG can aid in objective assessment of temporal-spatial distribution of activity and can refine targeted therapies like chemodenervation and biofeedback.

A combination of constraint-induced therapy and motor control retraining in the treatment of focal hand dystonia in musicians: a long-term follow-up study.

UNLABELLED: Focal hand dystonia (FHD) in musicians is a painless, task-specific motor disorder characterized by involuntary loss of control of individual finger movements. The aim of this study was to investigate the long-term effects of a combined behavioral therapy intervention aimed at normalizing finger movement patterns. METHODS: Eight musicians with FHD had taken part in the 1-year study involving intensive constraint-induced therapy and motor control retraining at slow speed as the interventions. Four of these subjects volunteered to take part in this 4-year follow-up. A quasi-experimental, repeated measures design was used, with 9 testing sessions over 4 years. Video recordings of the subjects playing two pieces were used for data analysis. The Frequency of Abnormal Movements scale (FAM) was the main outcome measure. It was hypothesized that there would be significant differences in FAM scores achieved over the 4-year period. RESULTS: The results from the ANOVA revealed a significant decrease, by approximately 80%, in the number of abnormal movements for both pieces over the 4-year period (F=7.85, df=8, p<0.001). Tukey's post-hoc test revealed that significant improvements occurred after 6 months of therapy (p-values between p<0.001 and p=0.044). Although the results were not significant between month 12 and follow-up at year 4, the trend revealed that the progress achieved during the first year of intensive retraining was maintained at year 4. CONCLUSIONS: A 1-year period of intensive task-specific retraining may be a successful strategy with long-term, lasting effects for the treatment of musician's FHD. Results suggest that retraining strategies may need to be carried out for at least 6 months before statistically significant changes are noted.

Single-session tDCS-supported retraining does not improve fine motor control in musician's dystonia.

BACKGROUND: Focal dystonia in musicians (MD) is a task-specific movement disorder with a loss of voluntary motor control during instrumental playing. Defective inhibition on different levels of the central nervous system is involved in the pathophysiology. Sensorimotor retraining is a therapeutic approach to MD and aims to establish non-dystonic movements. Transcranial direct current stimulation (tDCS) modulates cortical excitability and alters motor performance. In this study, tDCS of the motor cortex was expected to assist retraining at the instrument. METHODS: Nine professional pianists suffering from MD were included in a placebo-controlled double-blinded study. Retraining consisted of slow, voluntarily controlled movements on the piano and was combined with tDCS. Patients were treated with three stimulation protocols: anodal tDCS, cathodal tDCS and placebo stimulation. RESULTS: No beneficial effects of single-session tDCS-supported sensorimotor retraining on fine motor control in pianists with MD were found in all three conditions. CONCLUSIONS: The main cause of the negative result of this study may be the short intervention time. One retraining session with a duration of 20 min seems not sufficient to improve symptoms of MD. Additionally, a single tDCS session might not be sufficient to modify sensorimotor learning of a highly skilled task in musicians with dystonia.

A combination of constraint-induced therapy and motor control retraining in the treatment of focal hand dystonia in musicians.

UNLABELLED: Focal hand dystonia (FHD) in musicians is a painless task-specific motor disorder characterized by an involuntary loss of control of individual finger movements. The aim of this study was to investigate the effects of an innovative behavioural therapy intervention, aimed at normalising movement patterns, in musicians affected by FHD. METHODS: Eight musicians volunteered to take part in this retraining protocol. Intensive constraint-induced therapy and motor control retraining at slow speed were the interventions. Video recordings of the subjects playing two pieces were used for data analysis. The Frequency of Abnormal Movements scale (FAM), the change in metronome speed achieved during motor control retraining, and two ordinal dystonia evaluation scales were chosen as outcome measures. It was hypothesised that there would be significant differences in the FAM scores and metronome speeds over a 12-month period. RESULTS: For the main outcome measure, the FAM scale scores, the two-factor repeated measures ANOVA revealed a very significant decrease in the number of abnormal movements per second of instrumental playing over the 12-month period (F = 6.32, df = 7, p < 0.001). Tukey's post-hoc tests carried out for the FAM scores revealed that significant changes occurred after 8 months of therapy. DISCUSSION: These results suggest that a combination of constraint-induced therapy and specific motor control retraining may be a successful strategy for the treatment of musicians' FHD. Furthermore, the results suggest that retraining strategies may need to be carried out for at least 8 months before statistically significant changes are noted.

Focal dystonia in musicians: phenomenology, pathophysiology, triggering factors, and treatment.

Musician's dystonia is a task-specific movement disorder that manifests itself as a loss of voluntary motor control in extensively trained movements. Approximately 1% of all professional musicians develop musician's dystonia, and in many cases, the disorder terminates the careers of affected musicians. The pathophysiology of the disorder is not completely clarified. Findings include 1) reduced inhibition at different levels of the central nervous system, 2) maladaptive plasticity and altered sensory perception, and 3) alterations in sensorimotor integration. Epidemiological data demonstrate a higher risk for those musicians who play instruments requiring maximal fine-motor skills. For instruments where workload differs across hands, focal dystonia appears more often in the more intensely used hand. In psychological studies, musicians with dystonia have more anxiety and perfectionist tendencies than healthy musicians. These findings strengthen the assumption that behavioral factors may be involved in the etiology of musician's dystonia. Preliminary findings also suggest a genetic contribution to focal task-specific dystonia with phenotypic variations including musician's dystonia. Treatment options include pharmacological interventions, such as trihexyphenidyl or botulinum toxin-A, as well as retraining programs and ergonomic changes in the instrument. Patient-tailored treatment strategies may significantly improve the situation of musicians with focal dystonia. Positive results after retraining and unmonitored technical exercises underline the benefit of an active involvement of patients in the treatment process. Only a minority of musicians, however, return to normal motor control using the currently available therapies.

Auditory grip force feedback in the treatment of Writer's cramp.

STUDY DESIGN: Pre-post, single-group. INTRODUCTION: Writer's cramp (WC) is a focal dystonia causing impairments in daily life. Behavioral treatment approaches have been shown to improve handwriting performance, though outcomes remain sub-optimal. PURPOSE OF THE STUDY: To examine the effects of the handwriting training and auditory grip force feedback in seven patients with WC. METHODS: Handwriting performance was examined before and after treatment. Writing frequency, fluency, and pressure were recorded with a digitizing tablet and grip forces during handwriting were recorded. Subjective writing performance and pain were rated on visual analog scales. RESULTS: The treatment resulted in significant reductions in writing pressure and pain, while writing performance was significantly improved. CONCLUSIONS: Patients in this study with WC, who exhibit grip force and pressure problems, benefit from feedback-supported handwriting training.

Focal dystonia in musicians: treatment strategies and long-term outcome in 144 patients.

We present the long-term outcome of 144 musicians with focal dystonia after treatment with botulinum toxin (n = 71), trihexiphenidyl (n = 69), pedagogical retraining (n = 24), ergonomic changes (n = 51), or nonspecific exercises on the instrument (n = 78). Outcome was assessed by patients' subjective rating of cumulative treatment response and response to individual therapies. Seventy-seven patients (54%) reported an alleviation of symptoms: 33% of the patients with trihexiphenidyl, 49% with botulinum toxin, 50% with pedagogical retraining, 56% with unmonitored technical exercises, and 63% with ergonomic changes.

Changing the brain through therapy for musicians' hand dystonia.

Focal hand dystonia is a disorder in which sensory and motor anomalies emerge that appear to be grounded in maladaptive routes of cortical plasticity. Remodeling cortical networks through sensory-motor retuning (SMR), we achieved long-term reduction in the symptoms of focal hand dystonia. Magnetoencephalography confirmed that SMR modified the representational cortex of the fingers, whereby the representation of the affected hand was reorganized so that it resembled more the organization of the non-affected side. Furthermore, we observed differences in abnormal tactile acuity between patients with musician's cramp and those with writer's cramp: Using two-point finger discrimination, dystonic musicians showed perceptual asymmetry between hands, while writer's cramp patients did not. To further evaluate the occurrence of collateral disturbances in focal dystonia, we assessed the clinical histories of 101 affected musicians. An important finding from this study was that dystonic musicians who play a similar first and second instrument reported a continuous worsening of their symptoms. In addition, collateral disturbances appeared with a shorter delay when more than one instrument was played. Taken together, these studies suggest that (1) neurological dysfunction can be reversed by context-specific training protocols, (2) specific symptomatic and etiological differences among various forms of focal hand dystonia might result from different behavioral experiences and their central representation, and (3) the spread of symptoms might be prevented by avoiding training that implies movement patterns similar to the main affected task, and by reducing the amount of task-associated movement behavior.

Chronic stimulation of the globus pallidus internus for control of primary generalized dystonia.

Our experience of deep brain stimulation of the globus pallidus internus (GPi-DBS) for dystonia is summarized. A total of 5 patients with primary generalized dystonia underwent GPi-DBS. There were 3 males and 2 females. The age at onset of dystonia ranged from 8 to 45 years and the age at surgery for GPi-DBS ranged from 17 to 59 years. Two of the patients had been treated previously by bilateral thalamotomy or unilateral pallidotomy at other clinics and then developed new symptoms or recurrence. All were stimulated bilaterally. No surgical complications were encountered. The symptoms of dystonia were scored by the Burke-Fahn-Marsden dystonia rating scale (BFMDRS). The scores ranged from 18 to 62 before surgery. An improvement in the symptoms of dystonia was observed soon after the initiation of GPi-DBS, and additional progressive improvement was noted during a period of months or even years after surgery. The score at 6 months after surgery reached a level ranging from 4 to 23. The improvement in score ranged from -51% to -92%. GPi-DBS produced a marked effect even in patients who had previously undergone thalamotomy or pallidotomy. At 6 months after surgery, all patients were receiving bipolar stimulation with a wide interpolar distance, using contact 0 or 1 as the cathode and contact 2 or 3 as the anode. Stimulation was being performed at an intensity of around 2.0 V with a pulse width of 0.21 ms at a high frequency ranging from 120 to 140 Hz. GPi-DBS represents an important therapeutic option in many patients with primary generalized dystonia.

Treatment effectiveness for patients with a history of repetitive hand use and focal hand dystonia: a planned, prospective follow-up study.

Recent studies show that rapid, nearly simultaneous, stereotypical repetitive fine motor movements can degrade the sensory representation of the hand and lead to a loss of normal motor control with a target task, referred to as occupational hand cramps or focal hand dystonia. The purpose of this prospective follow-up study was to determine whether symptomatic patients in jobs demanding high levels of repetition could be relieved of awkward, involuntary hand movements following sensory discriminative retraining complemented by a home program of sensory exercises, plus traditional posture, relaxation, mobilization, and fitness exercises. Twelve patients participated in the study. They all had occupational hand cramps, as diagnosed by a neurologist. Each patient was evaluated by a trained, independent research assistant before treatment and three to six months after treatment, by use of a battery of sensory, motor, physical, and functional performance tests. Care was provided by a physical therapist or a supervised physical therapist student in an outpatient clinic. Patients were asked to stop performing the target task and to come once a week for supervised treatment that included 1) heavy schedules of sensory training with and without biofeedback to restore the sensory representation of the hand, and 2) instructions in stress-free hand use, mirror imagery, mental rehearsal, and mental practice techniques designed to stop the abnormal movements and facilitate normal hand control. Patients were instructed in therapeutic exercises to be performed in the home to improve postural alignment, reduce neural tension, facilitate relaxation, and promote cardiopulmonary fitness. Following the defined treatment period, all patients were independent in activities of daily living, and all but one patient returned to work. Significant gains were documented in motor control, motor accuracy; sensory discrimination, and physical performance (range of motion, strength, posture, and balance). This descriptive study that includes patients with occupation-related focal hand dystonia provides evidence that aggressive sensory discriminative training complemented by traditional fitness exercises to facilitate musculoskeletal health can improve sensory processing and motor control of the hand.