Botulinum toxin in the treatment of writer's cramp: a double-blind study

We treated 20 patients with writer's cramp in a double-blind, placebo-controlled study. Each patient received two treatments in tandem, one with botulinum-A toxin (BTX-A) injections and another with normal saline, separated by 3 months. Treatment order was randomized and unknown to the patient and physician. Patients were assessed before each treatment and 2 and 6 weeks after each treatment by objective measurements of pen control. Twelve patients had improvement in pen control after treatment with BTX-A, but only four had significant improvement in writing. BTX-A injections are effective in relieving symptoms in selected cases of writer's cramp, particularly in those with significant wrist-joint deviation.