Partitioning the labyrinth for the treatment of benign paroxysmal positional vertigo

Abstract

Partitioning the labyrinth is a new laser technique for the creation of controlled fibrous bands in the inner ear without permanent hearing loss .' The application of partitioning in benign paroxysmal positional vertigo (BPPV) is the first application of this ability to divide the inner ear in humans. Partitioning the posterior semicircular canal creates a fibrous band across both the perilymphatic and endolymphatic fluid spaces of the posterior semicircular canal. This fibrous band stops movement of the posterior semicircular canal endolymph. I hypothesize that when the movement of the endolymphatic fluid was halted, and because the interface between the cupula and the membranous labyrinth within ampulla was watertight, the motion of the cupula was halted both from angular motion (physiologic action) and from linear motion (as in cupulolithiasis). Indications for surgery include severe symptoms that are incapacitating to the point that they significantly affect the patient's occupation or life-style. Fourteen patients have undergone unilateral partitioning of a posterior semicircular canal. Mean age at the time of surgery was 51 years, with a range from 33 to 64 years. Ten were women and four were men. The positional vertigo was traumatic in five (three men and two women), and spontaneous in nine patients (one man and eight women). Mean symptom duration was 5.8 years, with range from 3 months to 20 years. Nine patients had continuous symptoms (mean 26 months, range 3 to 96 months). Five patients had intermittent symptoms (mean 11.2 years, range 16 to 240 months) . Eight patients had normal preoperative hearing (0 to 12 dB 3 frequency average), two patients had 17-dB hearing levels, and four patients had 30to 65-dB hearing levels. No pathological origin of the hearing losses was found during evaluation. , BPPV resolution occurred from 1 to 14 days postoperatively. As the applied laser energy was decreased (from 12 J to 1.2 1)1 the BPPV resolved more slowly. All 14 patients have remained free of positional symptoms during their 3 to 21 months postoperative period. Postoperative motion sensitivity was seen in all patients . The motion sensitivity was mild and of 1 to 6 weeks' duration when postoperative steroids are used (10 mg prednisone four times a day for 7 days). When postoperative steroids were not used, the motion sensitivity can be severe and of 8 to 10 weeks' duration. All patients followed up on a daily basis postopera-