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

Abstract

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.