Early botulinum toxin treatment of acute sixth nerve palsy

Eight patients with total sixth nerve palsy were treated with botulinum toxin injection to the antagonist non-paretic medical rectus, within eight weeks of the onset of the palsy. Within a few days seven of the eight gained fusion without the necessity of a marked head turn, and none complained of confusing reversal of diplopia. The same seven recovered full function. The mean follow-up period after the last injection was 20 months. Seven palsies were the result of head trauma and one was due to cerebro-vascular disease. This preliminary report suggests that early botulinum toxin injection of patients with recent onset sixth nerve palsy is beneficial. Although all of the patients may possibly have recovered full lateral rectus function without treatment, the aetiologies of their palsies were of the type that frequently do no resolve. A randomised double-blind study is necessary more precisely to determine the effectiveness of this form of therapy.