Writer′s Cramp - Treatment With Botulinum Toxin

Abstract

Writer′s cramp is undoubtedly the most frustrating and difficult focal dystonia to treat. We treated 33 patients (32 males and 1 female) with writer′s cramp with EMG-guided injection botulinum toxin (BTX). Muscle selection for injection was done clinically. Their mean age at presentation was 39.48+9.38 years (range 18-57 years) and mean duration of symptoms was 3.84+4.15 years (range 0.3-20 years). A detailed clinical assessment and video-taping while writing was done. Fourteen (42.4%) of the 33 patients received injections in forearm extensors, 10 (30.3%) in flexors and 9 (27.3%) in both extensors and the flexors. Mean dosage of BTX used for initial injections was 127.7+28.4 units of Dysport and 22.9+3.1 units of Botox for twenty-tow and eleven patients respectively. Functional improvement was seen in 30(93.75%) and was marked to striking in 15(46.9%) of 32 patients who reported for follow-up. More patients with extensor (44.4%) patients with both flexor and extensor involvement had similar response. While BTX therapy is currently the most effective therapy for Writer′s cramp, it is also the most challenging indication for BTX. This is a technically demanding procedure requiring meticulous documentation.