Botulinum toxin in the treatment of writer's cramp.

ABSTRACT

BACKGROUND: Writer's cramp is a task specific focal dystonia. The treatment of writer's cramp is very disappointing. AIM: Study the effect of botulinum toxin (BTX) in the treatment of writer's cramp. MATERIAL AND METHODS: Sixteen patients of writer's cramp (15 men, 1 woman) with mean age of 35.75 years and mean duration of symptoms for 3.64 years received 22 treatment sessions of botulinum toxin-A (BTX). All patients were evaluated before, 3 and 12 weeks after BTX therapy on a rating scale from 0-4 for ease of writing, abnormal posture and pain (0 = normal, 4 = very severe disability). The speed of writing was also recorded before and 3 and 12 weeks after therapy. Each patient also gave a global subjective assessment 12 weeks after BTX therapy. RESULTS: Follow up was available after 19 treatment sessions. Significant improvement was seen in all the parameters studied i.e. abnormal posture (p = 0.0039), pain (p = 0.0092), ease of writing of (p = 0.0025) and speed of writing (p = 0.0025). An improvement of 50% or more was observed after 13 treatment sessions. Asymptomatic weakness in the injected limb was seen in all patients but four patients complained of weakness of fingers. The mean onset of improvement was 10.68 +/- 4.32 days and mean duration of effect was 9.47 +/- 5.34 weeks. CONCLUSION: BTX is effective in the treatment of writer's cramp. The draw-backs are short duration of action and prohibitive cost.