The role of botulinum toxin in the management of sixth nerve palsy.

Fifty-five patients with sixth nerve palsy have been treated with Botulinum toxin injection to the antagonist medial rectus, either in isolation or in combination with rectus muscle surgery. Forty of these patients (72 per cent) obtained significant benefit from injection at some stage in their management. Botulinum toxin has a major role in conjunction with transposition muscle surgery for the treatment of complete unrecovered sixth nerve palsy. In less severe paresis, a functional cure may be obtained in a significant number of cases with the use of Botulinum toxin alone, 37 per cent in this series. No serious complications were observed. In view of the safety of this procedure it is reasonable to consider an injection of Botulinum toxin in any adult patient with a persisting sixth nerve palsy.