Botulinum toxin A in clinical medicine.

The results of the treatment with botulinum toxin A injection of 234 patients with blepharospasm and 73 with hemifacial spasm were reviewed. Visual function improved in the majority of patients with blepharospasm, and the improvement was sustained for up to 40 sets of injections. Mid and lower facial movements were also reduced in a minority of patients. However, a sub-group with pre-tarsal blepharospasm or persistent levator inhibition after treatment had a poor response. An average 75% reduction in abnormal movements was seen in cases of hemifacial spasm. Side effects of the treatment were usually mild and short lived.