Endolymphatic shunt: an evaluation by test results.

Failure in the endolymphatic shunt operation for Meniere's disease is reportedly 30% or more. The fact that many patients have relief from their symptoms following this surgery offers validity to the procedure. Pure tone audiograms and sinusoidal harmonic acceleration (rotary chair or rotary test, RT) were used concurrently to evaluate end-results of this operation in 31 patients with Meniere's disease. RT shows parameters of phase and labyrinthine preponderance (LP) calculated by a computer. LP was determined by separately integrating the total slow-phase output of the vestibulo-ocular reflex (VOR) to the left and right and converting the differences to percentages. Irritative and destructive lesions in Meniere's disease may be accurately resolved using this technique. It was not possible to predict with any accuracy the irritative-destructive parameter using pure tone audiometry. Patients who had irritative lesions fared better with the shunt operation. An analysis of these patients is made with RT.