Effect of treatment with botulinum toxin on neurogenic blepharospasm.

Botulinum toxin type A creates temporary localised flaccid paralysis after injection into skeletal muscle. Thirty four patients with blepharospasm, of whom 28 also had the oromandibular dystonia syndrome, were treated with injections of botulinum toxin type A into the orbicularis oculi, and 28 showed functional improvement after the treatment. A high incidence of local side effects occurred, especially partial ptosis, which was well tolerated. There were no systemic side effects. The average period of relief was 2.5 months, increasing to 2.8 months after a second injection. Functional improvement was limited in patients with severe associated dystonia.