Preoperative cVEMP Results Predict Developing Prolonged Dizziness After Vestibular Schwannoma Surgery

Objective: To assess pretreatment factors including preoperative vestibular function tests evaluated using cVEMP and caloric tests, which correlate with the development of prolonged dizziness after vestibular schwannoma resection. Study Design: Retrospective cohort study. Setting: Academic tertiary referral centers. Patients: Patients with vestibular schwannoma who underwent surgery and completed preoperative vestibular function tests and questionnaires. Intervention: Diagnostic. Main Outcome Measures: Participants were divided into prolonged dizziness and nonprolonged dizziness groups according to their postoperative DHI scores. The rates of abnormal results of preoperative vestibular function tests (caloric test, cVEMP), including other factors such as preoperative HADS scores, were compared. Furthermore, univariate logistic regression analysis was performed with the DHI score at 3 months as the dependent variable. Results: Of the whole 45 participants, 14 (31%) developed prolonged dizziness postoperatively. The proportion of participants with abnormal cVEMP results was significantly lower in the prolonged dizziness group (7.1%) than in the nonprolonged dizziness group (42%). Other factors did not show any significant differences. Univariate analysis showed that only the cVEMP results correlated with the postoperative DHI score (OR = 9.39, 95% CI [1.56, 181.3], p < 0.05). About 70% of patients with prolonged dizziness continued to exhibit high DHI scores at 6 months after surgery; however, about half of them recovered by 1 year. Conclusion: Vestibular schwannoma patients with normal preoperative cVEMP results tended to develop prolonged dizziness after resection compared to those with abnormal results. Preoperative cVEMP results enable physicians to predict whether vestibular schwannoma patients undergoing resection would likely develop prolonged dizziness postoperatively.