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. Retraining also improved hand function as indexed by the Ann 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. (c) 2008 Movement Disorder Society