Treatment of sixth nerve palsy of traumatic or tumor etiology using botulinum toxin

PURPOSE: To study the treatment of sixth nerve palsies of traumatic or tumoral etiologies using botulinum toxin. The factors and possible influences are analysed. METHODS: 35 patients with unilateral sixth nerve palsy are studied, 21 presenting traumatic (group I) and 14 with tumoral etiology (group II). They have been treated with botulinum toxin into the medial rectus muscle, using topical anesthesia. In group I the mean preoperative deviation was 59 diopters, in group II it was 37 diopters. The follow-up time, the initial deviation, the dose, the number of injections, the colateral effects and the final results are analyzed. RESULTS: In group I, the mean number of injections was 1.7, and the dose 10.23 international units, success was achieved in 38% of the patients, better results are obtained when treatment is injected within six months after traumatism, when less initial deviation and better initial lateral muscle function are present. In group II, the mean number of injections was 1.5 and the dose 8.21 international units, success was achieved in 57%, no influence among these factors was found. CONCLUSIONS: We consider useful to treat the traumatic palsy with botulinum toxin within six months after traumatism. The results depend on the initial deviation and the previous lateral muscle function. It is also useful as a chronic treatment and as a diagnosis procedure.