Vertigo and Dizziness in Acoustic Neurinoma

Abstract

Vestibular findings were studied in 27 patients with acoustic neurinoma. Four of them had experienced vertigo and/or dizziness at the onset of the disease, and 14 other patients had these complaints during the course. Vestibular symptoms were more prominent with middle-sized tumors which extended to the posterior cranial fossa than with those in the internal auditory canal. Although most acoustic neurinomas originate from the vestibular nerve, the incidence of vestibular symptoms is rather infrequent. This is probably due to a compensating mechanism of the central nervous system while the tumor grows slowly. Therefore, the growth rate of the tumor is considered to be most important for the concomitance of vestibular symptoms. The origin of the tumor was identified in 13 cases; in 3 it was from the inferior vestibular nerve and in 10 from the superior vestibular nerve. No significant difference in caloric test results could be seen between the tumors of different origins. The incidence of vestibular symptoms was more frequent when the tumor originated from the superior vestibular nerve than from the inferior vestibular nerve. The recover time required from the dysequilibrium after extirpation of the tumor depended on the degree of preoperative vestibular function.