Writer's cramp:: Long-term treatment with botulinum toxin A

Graphospasm. (writer's cramp) a focal dystonia affecting as a rule the small muscles of the forearm and hand. Writer's cramp is difficult to treat by medicamentous therapy, in some patients very limited use of benzodiazepines or anticholinergics is possible. At present the method of first choice in patients with writer's cramp is the local application of botulotoxin A. In 1995-2001 in the Centre for Abnormal Movements and Parkinsonism at the First Neurological Clinic of the St. Anne Faculty Hospital in Brno 15 patients with writer's cramp were systematically treated with botulotoxin A. All patients were subjected before the first administration of botulotoxin A to a polymyographic examination to assess the dystonic pattern and to define the leading muscles of the dyskinesia. Botulotoxin A was always administered under electromyographic control. The patients were assessed four weeks after the first administration and then in three-month intervals. The effect of administration was evaluated on the basis of the ability to write, character of the writing, self-evaluation of the patients, clinical neurological examination and the CGI-Clinical Global Impression scale. The onset of the effect was evaluated, its duration and side-effects after local application of botulotoxin A. A positive effect of systematic therapy was present in 10 patients (66.7%), in 4 patients (26.7%) there was no marked improvement, one female patient (6.7%) developed after 3 years of successful treatment secondary lack of response to further botulotoxin A injections. The therapeutic effect according to the CGI score was 1.7 (SD=+/-1.0) degrees, undesirable effects were recorded in 1.8 (SD+/-1.0) degrees after the first administration, after sub-sequent administrations of CGI the degree of effectiveness 1.7 (SD=+/-0.9) and the degree of undesirable effects was 2.1 (SD=+/-0.4). The mean number of botulotoxin A injections during the follow-up period was 6.5 (SD=+/-5.0), range 1-20, the mean dose of botulotoxin A per therapeutic session was 242 (SD=+/-84) units of Dysport((R)) and 64 (SD+/- units Botox((R)) resp. The onset of a positive effect was apparent 8.8 (SD=+/-6.2) days after the first administration and 6.4 (SD=+/-4.8) days after repeated administrations. The mean interval between individual administrations was 130 (SD=+/-79.8) days between the first and second one and between the subsequent ones 156(SD=+/-67.8) days. The authors did not noced a declining effect of local administration of botulotoxin A nor the need to increase the dosage during long-term administration. The most common side-effect was temporary weakening of the strength of the injected muscles without a long-term effect (34% of the injections). Treatment of writer's cramp by local injections of botulotoxin A is an effective and safe method, side-effects are short and do not call for specific treatment or provisions.