The retrolabyrinthine approach and vascular loop.

Several researchers have made progress toward determining the cause of hemifacial spasm, tinnitus, and episodic vertigo. During the past 5 years, we have encountered a vascular loop in six of 36 patients who were undergoing retrolabyrinthine vestibular neurectomy for recurrent disequilibrium and vertigo. In five of these six patients, disequilibrium improved after neurectomy. This report describes the clinical symptomatology and the results of preoperative cochleovestibular testing for those patients found intraoperatively to have a vascular loop and suspected neurovascular compression syndrome. Audiograms, although varied, characteristically did not demonstrate the low-frequency sensorineural hearing loss characteristic of Meniere's disease. No preoperative marker, with the single exception of computed tomography pneumocisternography, dependably predicted the presence of a vascular loop.