Vestibular Assessment and Compensation in Unilateral Acute Vestibular Dysfunction: A Prospective Single-Armed Cohort Study of Vestibular Schwannoma After Surgery.

Abstract

Acute vestibular syndrome is highly disabling in physical and psychological stress of patients. The aim of this study was to evaluate the effects of perioperative vestibular dysfunction in patients who received unilateral vestibular schwannoma (VS) surgery as unilateral acute vestibular dysfunction model cases and to study the vestibular compensation process in these patients. The 101 participants with unilateral VS had received a series vestibular function tests including subjective visual vertical/horizontal (SVV/SVH), caloric test, cervical vestibular-evoked myogenic potentials, ocular VEMP, and video head impulse test within 3 months before surgery. SVV, SVH, and Visual Analog Scale for vertigo were evaluated on the first day (postoperative day 1, POD 1), on the third day (POD 3), on the 7 day (POD 7), in the first month (POD 30), and in the third month (POD 90) of postoperative follow-up visit. The tilts of SVV and SVH significantly increased after surgery compared with baseline on POD 1, POD 3, and POD 7. The SVV of the participants had recovered to the preoperative level on POD 30, and the SVH of the participants had recovered to the preoperative level on POD 90. The changes of SVV/SVH were significantly correlated with changes of Visual Analog Scale for vertigo within 90 days. After surgery, the tilts of SVV and SVH within 7 days were significantly higher in patients with normal caloric tests and video head impulse test than those with abnormal results in these 2 tests. Static vestibular function may recover effectively within 1 month after surgery in VS, which was positively correlated to the recovery of subjective dizziness. Patients with preoperative vestibular dysfunction may recover sooner and better in the process of vestibular compensation in the early postoperative stage compared with those with normal preoperative vestibular function.