Botulinum toxin in the treatment of dystonias--a hospital based study.

BACKGROUND Dystonia is a neurological disorder usually of idiopathic etiology with a wide spectrum of clinical manifestations. The advent of botulinum toxin has revolutionized the treatment of focal dystonias. This study was a prospective long term study to see the efficacy of botulinum toxin in the treatment of dystonias. MATERIAL AND METHODS There were a total of 215 injection sessions of botulinum toxin during a period of 4 years and 8 months. Patients were evaluated in detail and their severity of dystonias was graded on objective scales. Botulinum toxin injection were administered depending on the type and severity of dystonias. The response to treatment was gauged in terms of latency, and the degree and duration of improvement. The dosages were repeated as and when required, with minimal interval of 3 months. RESULTS We had a total number of 215 injection sessions, with maximum patient sessions with blepharospasm and hemifacial spasm (59 and 61, respectively). The lowest dosages of botulinum toxin were required for writer's cramps and blepharospasm (92.5 +/- 5.3; and 122 +/- 5.1) while highest dosages were required for generalized and cervical dystonias (512 +/- 10.5; and 452.5 +/- 8.5). The best response in terms of different parameters assessed was seen with blepharospasm and hemifacial spasm while it was lowest for the generalized dystonia group. We did not observe any declining responsiveness to botulinum toxin with repeated injections. The side effects were minimal and self-limiting. CONCLUSION Botulinum toxin injection is an effective and safe modality for the treatment of disabling dystonias. Cost is one of the major hinderances to its widespread use.