Therapy of abducens nerve paralysis

Abstract

In cases of unilateral paralyses of a lateral rectus, different operative procedures are recommended in the literature. Six typical cases are presented in this paper. Fourteen days after neurosurgical transsection of the abducens nerve, no restriction of abduction was found. The transposition procedure according to Hummelsheim was performed with good results. In three long-standing cases, botulinum toxin was used to ameliorate the contracture of the tight medial rectus muscle. In all cases no limitation of abduction was found intraoperatively, making the transposition procedure much easier to perform. In another complicated case, a unilateral recession/resection procedure was carried out. The postoperative alignment was good, but the motility and the useful field of binocular vision were restricted. In the last case, the absent function of the lateral muscle was restored using a silicon rod fixed in the lateral wall of the orbit. The field of binocular single vision ranged from 12 degrees adduction to 23 degrees abduction 3 months after operation. Second operations are easy to perform on completely transposed muscles and in cases of recession/resection procedures, but not easy nor predictable after Hummelsheim operations. Botulinum toxin is a useful adjunct in cases of sixth nerve paralyses.