[Results of long term treatment of essential blepharospasm and facial hemispasm with botulinum toxin A].

Botulotoxin A (BT) was administered to 51 patients (40 patients with essential blepharospasm, 11 patients with facial hemispasm) 299 times since December 1993 till January 2002. Total doses of 20-48 U of the preparation BOTOX (Allergan Inc.) were administered bilaterally in essential blepharospasm, doses of 12-24 U were administered unilaterally in facial hemispasm. The mean duration of therapeutic effect evaluated by the patient was 12.2 weeks (3-28 weeks) in the blepharospasm group and 13.8 weeks (7-35 weeks) in the hemispasm group. No general side effects were noted. Local complications in the blepharospasm group were observed in 8.83% (ptosis in 5.62%) and those in the facial hemispasm in 8.16% (ptosis in 2.04%) from the total number of BT administration in the respective groups. The therapeutic effect during the long-term administration was decreasing and required increasing doses of BT by more than 10%, as observed in 9 patients with essential blepharospasm (22.5%). The mean increase of BT dose required to maintain sufficient therapeutic effect was by 32% (14-66%). Two patients with the longest 8-year period of observation have not required increasing dosages above 16 U unilaterally over the last 5 years. The treatment with BT-A exerted the same effects in most cases even during long-term therapy lasting several years. The need to increase the doses of the administered BT was more frequent during the first two years of the treatment. Locally administered botulotoxin A is a safe and efficient remedy for the therapy of essential blepharospasm and facial hemispasm, the efficiency being unchanged in more than 80% of patients.