Abstract
Objective: To determine diagnostic parameter and value of vestibular evoked myogenic potential (VEMP) for screening test of acoustic neuroma (AN).
Study design: Retrospective clinical study.
Setting: Tertiary referral center.
Participants: Forty patients with unilateral acoustic tumor for whom VEMP test was performed and 14 healthy controls.
Main outcome measures: Amplitude of P13 and n23, p13 and n23 latencies and interaural p latencies and interaural n latencies in VEMP test were analyzed in patients group and controls group. Correlation between tumor size and Amplitude of P13 and n23, p13 and n23 latencies were analyzed in patients group. Sensitivity of VEMP, Auditory brainstem response (ABR) and caloric test were also reviewed.
Results: Significantly smaller amplitude of p13 and n23, longer p13 and n23 latencies and longer interaural p latencies were shown in AN patients. Cases with large tumors have shown a tendency with absent or small amplitude response while small tumors have tended to have prolonged n23 latencies. Among forty patients, 29 showed abnormal results of VEMP. Thus sensitivity rate of VEMP was 72.5%, which has no significant difference when compared to that of ABR and Caloric test.
Conclusion: These results suggest that amplitude difference, p13 latencies, n23 latencies and interaural p latencies are useful diagnostic parameters for AN. Therefore VEMP can be one of important battery tests for clinical application in making diagnosis of AN.
