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.