Vascular compression syndrome of the eighth nerve. Clinical correlations and surgical findings.

A recently described syndrome, disabling positional vertigo (DPV), is characterized by persistent and progressive vertigo that is always associated with nausea and occasionally with vomiting; symptoms are made worse with changes in head position and are lessened with bedrest. Patients with DPV have abnormal results on vestibular testing and abnormalities in auditory nerve conduction as indicated by subtle but distinct alterations in brain stem auditory evoked potentials (BAEP). Microvascular decompression (MVD) of the vestibular nerve and, when indicated, the cochlear portion of the eighth cranial nerve has been highly successful in returning patients with DPV to normal lifestyles. Intraoperative monitoring of BAEP and auditory nerve compound action potentials have reduced the incidence of hearing loss, the major complication of MVD of the eighth nerve, to about 3 per cent. This article details the results of evaluating and treating 41 patients with DPV by MVD over a 12-month period and reports a success rate for this procedure in these patients of 73 per cent.