Dystonia Disability Scale Research Articles

Outcomes of Unilateral Pallidotomy in Focal and Hemidystonia Cases: A Single-Blind Cohort Study.

The role of deep brain stimulation in the treatment of dystonia has been widely documented. However, there is limited literature on the outcome of lesioning surgery in unilateral dystonia. We restrospectively reviewed our cases of focal and hemidystonia undergoing unilateral Pallidotomy at our institute to evaluate the short-term and long-term outcome. Patients who underwent radiofrequency lesioning of GPi for unilateral dystonia between 1999 and 2019 were retrospectively reviewed. All patients were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and Dystonia Disability Scale (DDS) preoperatively at the short term follow-up (<1 year) and at long-term follow-up (2-7.5 years). Video recordings performed at these time points were independently reviewed by a blinded movement disorders specialist. Eleven patients were included for analysis. The preoperative, short-term, and long-term follow-up motor BFMDRS and DDS scores were 15.5 (IQR [interquartile range]: 10.5, 23.75) and 10.5 (IQR: 6.0, 14.5); 3.0 (IQR: 1.0, 6.0, P = 0.02) and 3.0 (IQR: 3.0, 8.0, P = 0.016); and 14.25 (IQR: 4.0, 20.0, P = 0.20) and 10.5 (IQR: 2.0, 15.0, P = 0.71) respectively. For observers B, the BFMDRS scores at the same time points were 19 (IQR: 12.5, 27.0), 7.5 (IQR: 6.0, 15.0, P = 0.002), and 21 (IQR: 7.0, 22.0, P = 0.65) respectively. The improvement was statistically significant for all observations at short-term follow-up but not at long-term follow-up. Pallidotomy is effective for hemidystonia or focal dystonia in the short term. Continued benefit was seen in the longer term in some patients, whereas others worsened. Larger studies may be able to explain this in future.

The Technical Ability and Performing Scale (TAPS): A newly developed patient-reported functional rating scale for Musician's focal dystonia

BackgroundMusician's Focal Dystonia (MFD) is the most common adult-onset dystonia involving the hand and can cause a professional music career to end. MFD affects about 1% of professional musicians and is a challenging clinical condition to treat. This work aimed to validate the Technical Ability and Performing Scale (TAPS), a newly-developed patient-reported functional rating scale for the clinical assessment of the MFD burden. MethodsSeventy-seven musicians with MFD (40.84 ± 13.14 years) who accessed “Sol Diesis Service” were consecutively enrolled. Each subject filled in the TAPS after playing six technical passages of different complexity for 45 s each. The clinicians also collected the Arm Dystonia Disability Scale (ADDS) and Tubiana-Chamagne Scale (TCS). Cronbach's α coefficient was used to assess reliability; concurrent validity was measured using correlation with validated tools (ADDS and TCS). ResultsOur results showed that the symptoms of dystonia appeared at around 33 years of age and lasted for at least three years. The Cronbach's α displayed good internal consistency (0.817) for Technical Ability (TA). The two TAPS scores, TA and Performing Score (PS), positively correlated with TCS total score and negatively with ADDS total score (concurrent validity). ConclusionsThe TAPS is a reliable and valid tool for the clinical assessment of the MFD burden. This patient-reported outcome measure may facilitate patient engagement in decision-making about their care and can help healthcare professionals to monitor the musician's change during the rehabilitative intervention.

Efficacy and Safety of Zolpidem for Focal Dystonia After Neurosurgical Treatments: A Retrospective Cohort Study.

Although there are several reports of the significant efficacy of zolpidem for treating dystonia, zolpidem is still considered an anecdotal treatment. Here, we evaluated the efficacy and safety of zolpidem for treating residual dystonia in patients who previously received various neurosurgical treatments majorly including deep brain stimulation and radiofrequency ablation. We retrospectively reviewed medical records from January 2021 to September 2021 to identify patients with dystonia who had been prescribed zolpidem after undergoing neurosurgery. Twenty patients were enrolled in this study, including those with blepharospasm (two), tongue dystonia (four), mouth dystonia (one), spasmodic dysphonia (two), cervical dystonia (six), focal hand dystonia (three), hemidystonia (two), blepharospasm with cervical dystonia (one), and mouth dystonia with cervical dystonia (one). Single doses of zolpidem ranged between 2.5 and 10 mg, while daily dosages ranged from 10 to 30 mg. The zolpidem dose prescribed was 5–10 mg, with single and daily doses of 7 ± 2.9 and 14.5 ± 6.0 mg, respectively. With zolpidem administration, the participants' Burke-Fahn-Marsden Dystonia Rating Scale-Movement Scale score significantly improved from 8.1 ± 6.7 to 3.7 ± 2.5 (50.6% improvement, p < 0.0001). Improvements in arm dystonia, blepharospasm, and spasmodic dysphonia were observed using the Arm Dystonia Disability Scale, Jankovic Rating Scale, and Voice Handicap Index, respectively. No improvements were observed in cervical dystonia on the Toronto Western Spasmodic Torticollis Rating Scale. Drowsiness, including three cases each of mild and moderate drowsiness, was the most frequent adverse effect (30%), which persisted for 2–3 h. Transient amnesia and rapid eye movement sleep behavior disorder occurred in two patients and one patient, respectively. Although our findings suggest that zolpidem can be a valuable treatment option for patients with residual dystonia after neurosurgical treatments, the beneficial effects for cervical dystonia were limited.

Magnetic Resonance‐Guided Focused Ultrasound Thalamotomy for Focal Hand Dystonia: A Pilot Study

ABSTRACTBackgroundThe efficacy of magnetic resonance‐guided focused ultrasound (MRgFUS) thalamotomy for the treatment of focal hand dystonia (FHD) is not well known.ObjectiveWe aimed to prospectively investigate the efficacy of MRgFUS thalamotomy for the treatment of FHD.MethodsWe performed MRgFUS thalamotomy of the ventro‐oral (Vo) nucleus in 10 patients with FHD. We evaluated the scores of the Writer's Cramp Rating Scale (WCRS, 0–30; higher scores indicating greater severity), Tubiana Musician's Dystonia Scale (TMDS, 0–5; lower scores indicating greater severity), and Arm Dystonia Disability Scale (ADDS, 0%–100%; lower scores indicating greater disability) at baseline and 3 and 12 months post‐treatment.ResultsWCRS, TMDS, and ADDS scores significantly improved from 6.3 ± 2.7, 1.4 ± 0.5, and 58.7% ± 14.3% at baseline to 1.6 ± 3.1 (P = 0.011), 5.0 ± 0 (P = 0.0001), and 81.6% ± 22.9% (P = 0.0229) at 12 months, respectively. There was one prolonged case of dysarthria at 12 months.ConclusionWe show that MRgFUS Vo‐thalamotomy significantly improved FHD. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Minimal Clinically Important Differences for Burke-Fahn-Marsden Dystonia Rating Scale and 36-Item Short-Form Health Survey.

Although an increasing number of trials are reported on the treatment of generalized or segmental isolated dystonia, the minimal clinically important difference thresholds for the most frequently reported outcome measures are still undetermined. To estimate the minimal clinically important difference for the Burke-Fahn-Marsden Dystonia Rating Scale and the 36-Item Short-Form Health Survey in generalized or segmental dystonia. A total of 898 paired examinations of 198 consecutive patients, aged >18 years, with idiopathic and inherited (torsin family 1 member A positive) segmental and generalized isolated dystonia were analyzed. To calculate the minimal clinically important difference thresholds, both anchor- and distribution-based methods were used simultaneously. Any improvement >16.6% or worsening larger than 21.5% on the Burke-Fahn-Marsden Dystonia Rating Scale indicates a minimal, yet clinically relevant, change. Threshold values for the Burke-Fahn-Marsden Dystonia Disability Scale were 0.5 points for both decline and improvement. Cut-off scores for the Physical Component Summary, the Mental Component Summary, and the Global (Total or Overall) Score of the 36-Item Short-Form Health Survey were 5.5 and 5.5, 6.5 and 7.5, and 7.5 and 8.5 points for clinically meaningful improvement and deterioration, respectively. The minimal clinically important difference represents the smallest change in an outcome measure that is meaningful to patients. Our estimates for the Burke-Fahn-Marsden Dystonia Rating Scale and the 36-Item Short-Form Health Survey may allow more reliable judgment of the clinical relevance of different treatments for segmental and generalized isolated dystonia. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

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

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

Botulinum Toxin A And Task-specific Training For Hand Dystonia Due To 5 Year Old Stroke

Focal hand dystonia after stroke, a result of maladaptive plasticity, impairs hand function, affects daily activities, and undermines independence. A 59-year male patient, who had developed focal hand dystonia after suffering from ischemic stroke 5 years ago, received training following an injection of Botulinum Toxin A (BoNTA). Task-specific training for a duration of 60 minutes per day for 3 days per week was provided for 12 weeks. Assessments were done by using arm dystonia disability scale, action research arm test, Fugl-Meyer assessment of upper extremity, and stroke-specific quality of life. Substantial improvement was observed in all the parameters, at short-term follow-up.

POST-STROKE FOCAL HAND DYSTONIA

Objectives: To determine the effects of Botulinum toxin A (BoNTA) with taskspecific training on hand function and quality of life in patients with post stroke focal dystonia ofhand. Study Design: Randomized Controlled Trial. Place and Duration of Study: This studywas conducted in Holy family hospital, The Neurocounsel and Chambeli Rehabilitation centerfrom October 2015 to September 2016. Methodology: Both male and female patients sufferingfrom stroke for at least 6 months with focal hand dystonia were included in this randomizedcontrolled trial. 46 patients were recruited in the study through non probability purposivesampling and then were allocated to control (n=23) and experimental group (n=23) by randomnumber list generated for 46 patients using SPSS software. Control group was provided withonly task specific training while experimental group was provided with an injection of BotulinumToxin A in addition to task-specific training. Data was collected from both groups at baselineand then after 8 weeks by using Action Research Arm Test (ARAT), Stroke specific qualityof life (SS-QOL) and Arm dystonia disability scale (ADDS). Results: Although both groupsshowed significant improvements after training(P value &lt;0.001) in both ARAT scale and SSQOLbut as shown by the difference of means of the groups, experimental group has shownmore improvement than control group at the end of 8 weeks of intervention with P value&lt;0.05.ADDS has also shown better results in reducing disability in experimental group as compared tocontrol group. Conclusion: Botulinum toxin A prior to start of task specific training significantlyimproves outcome in post stroke focal hand dystonia patients than task specific training alone.

BOTULINUM TOXIN AND TASK SPECIFIC TRAINING

Objectives: To determine the effects of Botulinum toxin A (BoNTA) with taskspecific training on hand function and quality of life in patients with post stroke focal dystonia ofhand. Study Design: Randomized Controlled Trial. Place and Duration of Study: This studywas conducted in Holy family hospital, The Neurocounsel and Chambeli Rehabilitation centerfrom October 2015 to September 2016. Methodology: Both male and female patients sufferingfrom stroke for at least 6 months with focal hand dystonia were included in this randomizedcontrolled trial. 46 patients were recruited in the study through non probability purposivesampling and then were allocated to control (n=23) and experimental group (n=23) by randomnumber list generated for 46 patients using SPSS software. Control group was provided withonly task specific training while experimental group was provided with an injection of BotulinumToxin A in addition to task-specific training. Data was collected from both groups at baselineand then after 8 weeks by using Action Research Arm Test (ARAT), Stroke specific qualityof life (SS-QOL) and Arm dystonia disability scale (ADDS). Results: Although both groupsshowed significant improvements after training(P value &lt;0.001) in both ARAT scale and SSQOLbut as shown by the difference of means of the groups, experimental group has shownmore improvement than control group at the end of 8 weeks of intervention with P value&lt;0.05.ADDS has also shown better results in reducing disability in experimental group as compared tocontrol group. Conclusion: Botulinum toxin A prior to start of task specific training significantlyimproves outcome in post stroke focal hand dystonia patients than task specific training alone.

Differences in active range of motion measurements in the upper extremity of patients with writer's cramp compared with healthy controls

Study DesignExploratory case-control study. IntroductionWriter's cramp (WC) is a type of focal hand dystonia. The central nervous system plays a role in its pathophysiology, but abnormalities in the affected musculoskeletal components may also be relevant. Purpose of the StudyWe compared the active range of motion (ROM) in patients with WC and healthy volunteers (HVs) and correlated the findings with disease duration and severity. MethodsAffected limb joints were measured with goniometers. Patients were assessed at least 3 months after their last botulinum toxin (botulinum neurotoxin) injection, and strength was clinically normal. t tests were used to compare the ROMs of WC with matched HVs. The Spearman correlation coefficient assessed the relationship of active ROMs to the disease duration and handwriting subscore of the Dystonia Disability Scale. ResultsROMs of D1 metacarpophalangeal (MCP) joint extension as well as D2 and D5 MCP flexion were significantly smaller in WC, and distal interphalangeal joint extension in D3 and D5 was significantly greater compared with HVs. There were negative correlations between D2 MCP flexion and disease duration and with Dystonia Disability Scale. DiscussionAbnormalities in ROMs in WC were found. Severity and disease duration correlated with reduced D2 MCP flexion. This may be related to intrinsic biomechanical abnormalities, co-contraction of muscles, or a combination of subclinical weakness and atrophy from repeated botulinum neurotoxin injections. ConclusionsHand biomechanical properties should not be ignored in the pathophysiology of WC. Level of Evidence2c.

Anodal transcranial direct current stimulation to the cerebellum improves handwriting and cyclic drawing kinematics in focal hand dystonia.

There is increasing evidence that the cerebellum has a role in the pathophysiology of primary focal hand dystonia and might provide an intervention target for non-invasive brain stimulation to improve function of the affected hand. The primary objective of this study was to determine if cerebellar transcranial direct current stimulation (tDCS) improves handwriting and cyclic drawing kinematics in people with hand dystonia, by reducing cerebellar-brain inhibition (CBI) evoked by transcranial magnetic stimulation (TMS). Eight people with dystonia (5 writer’s dystonia, 3 musician’s dystonia) and eight age-matched controls completed the study and underwent cerebellar anodal, cathodal and sham tDCS in separate sessions. Dystonia severity was assessed using the Writer’s Cramp Rating Scale (WRCS) and the Arm Dystonia Disability Scale (ADDS). The kinematic measures that differentiated the groups were; mean stroke frequency during handwriting and fast cyclic drawing and average pen pressure during light cyclic drawing. TMS measures of cortical excitability were no different between people with FHD and controls. There was a moderate, negative relationship between TMS-evoked CBI at baseline and the WRCS in dystonia. Anodal cerebellar tDCS reduced handwriting mean stroke frequency and average pen pressure, and increased speed and reduced pen pressure during fast cyclic drawing. Kinematic measures were not associated with a decrease in CBI within an individual. In conclusion, cerebellar anodal tDCS appeared to improve kinematics of handwriting and circle drawing tasks; but the underlying neurophysiological mechanism remains uncertain. A study in a larger homogeneous population is needed to further investigate the possible therapeutic benefit of cerebellar tDCS in dystonia.

Dystonia due to cerebral palsy responds to deep brain stimulation of the globus pallidus internus

Cerebral palsy is the most common cause of pediatric-onset dystonia. Deep brain stimulation is gaining acceptance for treating dystonias in children. There is minimal reported experience regarding the efficacy of deep brain stimulation in cerebral palsy. Fourteen patients, including 8 younger than 16 years, received bilateral implants (13 patients) or a unilateral implant (1 patient) of the internal globus pallidus and were observed in a noncontrolled, nonblinded study for at least 6 months. Motor function was assessed using the Burke-Fahn-Marsden Dystonia Movement and Disability scales and the Barry Albright Dystonia Scale. By 6 months, significant improvement was observed in the Burke-Fahn-Marsden Dystonia Movement scale (P=.004), the Burke-Fahn-Marsden Dystonia Disability scale (P=.027), and the Barry Albright Dystonia Scale (P=.029) for the whole cohort (n=14) and in the patients treated before skeletal maturity (group 1; n=8): Burke-Fahn-Marsden Dystonia Movement scale, P=.012; Burke-Fahn-Marsden Dystonia Disability scale, P=.020; and Barry Albright Dystonia Scale, P=.027. Deep brain stimulation may offer an effective treatment option for cerebral palsy-related dystonia, especially in those treated before skeletal maturity.

External shock waves therapy in dystonia: preliminary results

Extracorporeal shock wave therapy (ESWT) has been shown to reduce hypertonia in patients with upper motor neuron syndrome without any side effect. The aim of the present study is to investigate whether ESWT could be useful also in patients with dystonia. We evaluated three patients with secondary dystonia and three patients with idiopathic writer's cramp. Placebo treatment was performed in each patient. ESWT was administered during four sessions (once weekly) to the target muscles of hand and forearm using an electromagnetic lithotripter (Modulith SLK--Storz Medical). Clinical evaluation was performed using the Unified Dystonia Rating Scale in patients with secondary dystonia and the Arm Dystonia Disability Scale in patients with writer's cramp. After treatment, the three patients with secondary dystonia showed a marked improvement which lasted at least until 1 month after the last session. In the patients with writer's cramp, the improvement after ESWT was less consistent being effective only in two subjects. There were no associated adverse effects. Extracorporeal shock wave therapy is probably an effective and safe treatment for upper limb dystonia, particularly for the secondary forms. Larger randomized studies are needed to confirm these preliminary results.

Motor re‐training does not need to be task specific to improve writer's cramp

Previous studies showed a beneficial effect of motor re-training in task-specific hand dystonia. Here we examined whether re-training needs to specifically focus on the task affected by dystonia. 21 patients with writer's cramp were randomly assigned to two types of re-training: One group of patients trained drawing and writing movements using a pen attached to the bottom of a finger splint. The second group used therapeutic putty to train finger movements without exercises of drawing and writing movements. Training lasted for 8 weeks. Before re-training, affected hand and forearm were immobilized for 4 weeks to facilitate the responsiveness to re-training. Dystonia was assessed during handwriting using the Writer's Cramp Rating Scale. Although no clinical improvement was observed immediately after immobilization, 8 weeks of re-training improved task-specific dystonia relative to baseline (P = 0.005). Both training modalities were equally effective. More severely affected patients benefited most. There was no correlation between disease duration and the individual treatment response. Re-training also improved hand function as indexed by the Arm Dystonia Disability Scale (P = 0.008). Kinematic handwriting analysis showed that re-training lowered vertical force level and enhanced the fluency of handwriting. We conclude that re-training does not need to specifically focus on the task affected by dystonia to be clinically effective.

Botulinum toxin treatment of lateral axial dystonia in parkinsonism

Lateral axial dystonia (LAD) has been described in patients with Parkinson's disease (PD), but treatment might be more controversial than treatment of LAD in other neurological conditions. Our study was designed as a blinded cross-over with botulinum toxin (BTX) and placebo in order to investigate the efficacy of BTX in PD LAD. Nine patients with LAD who failed to experience benefit from oral medications were randomly assigned to 2 groups, 4 patients received BTX and 5 placebo as a first treatment, and were switched-over to BTX or placebo in the following treatment session, performed 3 months after the first session. Each patient was evaluated at baseline, 2 and 4 weeks after injection and after 3 months follow-up with the Trunk Dystonia Disability Scale (TDDS), a Visual Analogue Scale (VAS) and a goniometric measurement of the lateral displacement. Patients were videotaped at each visit. None of the patients of the placebo group experienced benefit from treatment. BTX treatment was effective in 6 patients. One patient reported subjective benefit, with improvement of VAS score and mild improvement of TDDS score, but with no improvement of flexion degree. Two patients did not report any benefit. Four patients opted to continue to receive BTX treatment for 2 years after the cross-over study. Our study shows that BTX could be considered a possible treatment for LAD in parkinsonism.

How to assess motor impairment in writer's cramp

Writer's cramp is a task-specific hand dystonia affecting handwriting. Clinical scores such as the Arm Dystonia Disability Scale (ADDS) or Writer's Cramp Rating Scale (WCRS) as well as kinematic analysis of handwriting movements have been used to assess functional impairment in affected patients. In 21 patients with writer's cramp and healthy controls, we analyzed the kinematics of writing and cyclic drawing movements. We rated the severity of dystonia using the ADDS and WCRS and correlated the clinical scores with movement kinematics. Mean stroke frequency was significantly reduced in dystonic patients. Drawing movements showed more frequently a decrease in stroke frequency than handwriting movements. During circle drawing, mean vertical peak velocity was more variable in patients relative to controls, indicating an impaired ability to reproduce the same kinematic pattern over time. An increase in vertical writing pressure was only observed during handwriting but not during circle drawing and may reflect a compensatory effort to stabilize the pencil. Kinematic measures and individual ADDS and WCRS scores did not correlate with each other. The lack of correlation is not surprising as ADDS, WCRS, and kinematic analysis probe different aspects of motor impairment. The ADDS characterizes how dystonia affects a set of fine manual tasks, whereas the WCRS scores the manifestation of dystonia during handwriting. Therefore, the clinical scores and kinematic analysis of handwriting provide complementary insights into motor impairment. Future studies need to address which combination of clinical scores and kinematic measures are most appropriate to quantify impairment in writer's cramp.

Slow-Down Exercise for the Treatment of Focal Hand Dystonia in Pianists

Twenty professional pianists (10 males, 10 females; average age, 30.0 yrs) with focal hand dystonia were treated through slow-down exercise (SDE) therapy with successful results. SDE consisted of 5 steps: (1) The patients chose the musical piece which causes a dystonic hand movement. (2) Patients reduced the performance speed until the dystonic hand movement disappeared, and they recorded the slowed speed with a metronome. (3) At the slowed rate, patients repeatedly rehearsed the musical piece for 0.5 hr/day for 2 weeks. Other than the SDE, they were allowed to practice playing the piano freely. (4) After 2 weeks, patients attempted to increase their speed from 10% to 20%. If symptoms did not appear under the increased movement speed, patients proceeded to increase the speed of practice for an additional 2 weeks. If the dystonic motion appeared under the increased speed, patients returned to the slower speed of movement. (5) After 2 weeks, Step 4 was repeated and the performance speed was gradually increased. The performance speed was decreased by an average of 12.4 % of normal. Clinical results evaluated by the Arm Dystonia Disability Scale (ADDS) indicated that prior to performing the SDE, 4 subjects experienced moderate difficulty (ADDS = 2) and 16 subjects had marked difficulty (ADDS = 3). However, after SDE therapy, symptoms improved to normal (ADDS = 0) in 12 subjects and to mild (ADDS = 1) in 8 subjects. Clinical results evaluated by the Tubiana and Chamagne Score (TCS) showed significant (p &lt; 0.05) improvement from 2.2 ± 0.41 to 4.6 ± 0.50.

A New Method for Quantification of Musician's Dystonia: The Frequency of Abnormal Movements Scale

There is currently, no validated objective method available for the quantification of musicians dystonia applicable to different types of instrumentalists. To address this issue, we developed the Frequency of Abnormal Movements (FAM) scale and assessed its intra- and inter-rater correlation and concordance, internal consistency, and responsiveness. We also compared the FAM scale to the arm dystonia disability scale (ADDS) and Burke-Fahn- Marsden (BFM) scale. Eighteen patients with musicians dystonia were videotaped playing their instruments before and after sensory motor retuning therapy. Two raters, blinded to the order of the randomized video segments, independently rated each segment using the FAM, ADDS, and BFM scales. Intra-rater correlation (intraclass correlation coefficient [ICC] = 0.92, Spearmans rho = 0.87), concordance (weighted kappa = 0.76), and internal consistency (Cronbachs a = 0.96) for the FAM scale were good. Inter-rater correlation and concordance were better for the FAM scale (weighted k = 0.94, ICC = 0.96, Spearmans rho = 0.90) than for the ADDS or BFM scales (weighted k = 0.56-0.57, ICC scale = 0.81-0.82, Spearmans a = 0.68-0.76). The decrease in the FAM after 1 week of sensory motor retuning therapy was less likely to be due to chance (p = 0.06) than the decrease in the ADDS or BFM scales (p = 0.21-0.53). The FAM scale may be useful for clinical and research evaluations of patients with musicians dystonia.

Quantification of focal dystonia in pianists using scale analysis.

Focal dystonia in pianists is a task-specific movement disorder that causes loss of pianistic skills and provokes irregularities in playing. So far, no method has been available for objective quantification of the disorder. Eight professional pianists with focal dystonia and eight healthy professional pianists matched by age, gender, and handedness were examined, using a newly developed MIDI-based Scale Analysis as well as the Arm Dystonia Disability Scale (ADDS). Key velocities and timing parameters were analyzed. In 5 pianists with dystonia, follow-up examinations were carried out after treatment with botulinum toxin-A. In affected hands, significantly higher mean standard deviations of timing parameters were seen compared with healthy reference hands. After treatment with botulinum toxin-A, significant improvements in performance parameters were monitored by Scale Analysis. Mean standard deviations of inter-onset intervals correlated with ADDS scores. We conclude that Scale Analysis is an effective and precise tool for quantification of focal dystonia in pianists and provides fine resolution. It is independent of rating methods and allows reliable follow-up examinations during treatment.

Limb immobilization for the treatment of focal occupational dystonia.

Occupational focal upper-limb dystonia is characterized by involuntary muscle contractions that selectively interfere with the execution of specific motor tasks such as writing or playing a musical instrument. Occupational dystonias have a severe social impact, especially in certain professions. The available medical treatments offer little benefit. In eight patients with idiopathic occupational focal dystonia of the upper limb, the dystonic forearm and hand were immobilized with a plastic splint for mean (+/-SD) 4.5 +/- 0.75 weeks. Before splinting (base line) and at various intervals afterwards (4, 12, and 24 weeks), the authors assessed the severity of dystonia and the patients' motor performance objectively (Arm Dystonia Disability Scale and Tubiana and Chamagne Score) and subjectively (Self-Rating Score). Assessment 4 weeks after splint removal, when patients had regained normal voluntary movements, showed that the severity of dystonia and the patients' performance of the impaired motor task had improved; the benefit persisted unchanged at later follow-up visits (Arm Dystonia Disability Scale: base line 20.6 +/- 30.2%; after 4 weeks 83.9 +/- 23.8%, p = 0.007; after 12 weeks 83.9 +/- 23.8%, p = 0.007; after 24 weeks 79.7 +/- 29.5%, p = 0.015. Tubiana and Chamagne Score: base line 28.6 +/- 22.7%; after 4 weeks 80.0 +/- 23.1%, p = 0.015; after 12 weeks 80.0 +/- 23.1%, p = 0.015; after 24 weeks 74.3 +/- 32.1%, p = 0.031. Self-Rating Score: base line 20.6 +/- 19.3%; after 4 weeks 63.7 +/- 25.2%, p = 0.015; after 12 weeks 66.9 +/- 28.1%, p = 0.015; after 24 weeks 70.6 +/- 31.8%, p = 0.015). At the 24-week visit the improvement disappeared in one patient, was moderate in three, and marked in four. Limb immobilization can be a simple, effective, safe, and inexpensive treatment for focal occupational upper-limb dystonia.