Hyperactive rhizopathy of the vagus nerve and microvascular decompression. Case report.

A 37-year-old woman underwent microvascular decompression of the superior vestibular nerve for disabling positional vertigo. Immediately following the operation, she noted severe and spontaneous gagging and dysphagia. Multiple magnetic resonance images were obtained but failed to demonstrate a brainstem lesion and attempts at medical management failed. Two years later she underwent exploration of the posterior fossa. At the second operation, the vertebral artery as well as the posterior inferior cerebellar artery were noted to be compressing the vagus nerve. The vessels were mobilized and held away from the nerve with Teflon felt. The patient's symptoms resolved immediately after the second operation and she has remained symptom free. The authors hypothesize that at least one artery was shifted at the time of her first operation, or immediately thereafter, which resulted in vascular compression of the vagus nerve. To the authors' knowledge, this is the first reported case of a hyperactive gagging response treated with microvascular decompression. The case also illustrates the occurrence of a possibly iatrogenic neurovascular compression syndrome.