A critical appraisal of the role of auditory brain stem response and magnetic resonance imaging in acoustic neuroma diagnosis.

Auditory brain stem response (ABR) is the most sensitive and specific audiometric test for acoustic neuroma (AN) detection. The ABR sensitivity rate increases with tumor size; consequently, small tumors have notably low ABR sensitivity for detection. However, larger tumors also can fail recognition by ABR testing. The ABR must be viewed on its own merits compared to magnetic resonance imaging studies for the diagnosis of AN. Where does ABR fit into the screening process for detecting AN today?