Vestibular Symptoms before and after Removal of Acoustic Neurinoma

Vestibular symptoms before and after removal of acoustic neurinoma were studied in 47 patients in relation to the origin and size of the tumor and the caloric response. Vertigo and/or dizziness had been noted preoperatively in 26 of the 47 patients (55%). The incidence of such vestibular symptoms was significantly higher when the tumor originated in the superior vestibular nerve (SVN) than when its origin was the inferior vestibular nerve (IVN). No significant difference was seen in relation to tumor size. In patients with a small acoustic tumor or a normal caloric response preoperatively, postoperative vertigo tended to be prolonged. In 9 patients who were operated on through a middle cranial fossa approach, the duration of vertigo after surgery was analyzed further in relation to preservation of the remaining vestibular nerve. When tumors were IVN origin, postoperative vertigo lasted longer when the SVN was resected than when it was those preserved.