The sensitivity of auditory brainstem response testing for the diagnosis of acoustic neuromas

Objectives: To determine the sensitivity of auditory brainstem response (AB R) testing for detecting acoustic neuromas and to determine whether the tes t is less sensitive for detecting small tumors. Design: Retrospective review of the medical charts of 58 patients with acou stic neuroma who had all of the data necessary for inclusion in the study. Setting: University-affiliated referral practice of one neu rotologist. Patients: Patients with acoustic neuromas who had both ABR tracings and mag netic resonance imaging films available for review. Main Outcome Measures: Positive ABR and negative ABR results correlated wit h tumor size. Results: Turner size ranged from 0.4 to 7 cm. The overall sensitivity of AB R in diagnosing acoustic neuromas was 90%. However, ABR was progressively l ess sensitive with decreasing tumor size. Only 7 (58%) of the 12 tumors 1 c m or smaller were detected by ABR. Conclusion: Auditory brainstem response testing cannot be relied on for det ection of small acoustic neuromas and should not be used as a criterion to determine whether magnetic resonance imaging should be performed when an ac oustic neuroma is suspected clinically.