Botulinum toxin a in the treatment of blepharospasm: a 10-year experience.

To evaluate the long-term effect of botulinum toxin type A (BTX) in the treatment of blepharospasm, a retrospective analysis was conducted from the patients seen at the Movement Disorders Clinic of the Department of Neurology, Hospital das Clínicas, University of São Paulo School of Medicine from 1993 to 2003. A total of 379 treatments with BTX were administered to 30 patients with blepharospasm. Sixty six per cent of the subjects had used oral medication for dystonia and only 15% of them reported satisfactory response to this treatment. Ninety three per cent of the patients showed significant improvement after the first BTX injection. There was no decrement in response when compared the first and the last injection recorded. Adverse effects, mostly minor, developed at least once in 53% of patients. Six patients (20%) discontinued the treatment but there was no case of secondary resistance.