Vascular loop as a cause of vertigo.

A vascular loop in the internal auditory canal pressing upon the vestibular nerve was found in a series of eight patients with episodic vertigo and severe motion intolerance. All patients had failed medical and surgical therapy for vestibular Meniere's disease, which this syndrome closely mimics. A vestibular nerve resection or section medial to the vascular loop produced relief of symptoms in all patients, but one patient required a second operation. We have no test or study to reliably diagnose this syndrome preoperatively. The history appears to be the best indicator to date.