Botulinum toxin improves lid opening delays in blepharospasm-associated apraxia of lid opening.

Lid movement and EMG of the orbicularis oculi (OOc) were analyzed in 10 patients with apraxia of lid opening associated with blepharospasm before and after botulinum toxin treatment. The latencies to onset and to complete the eye opening and the time during which eye opening was sustained were studied in relation to OOc activity and compared with control values obtained in 12 healthy subjects. Following treatment there was an improvement of all lid opening measurements, a decrease of the abnormally prolonged OOc activity, and a reduction of the functional disability.