Auditory brain stem response wave IV-V abnormalities from the ear opposite large cerebellopontine lesions.

This report focuses on auditory brain stem response (ABR) from the ear contralateral to large cerebellopontine angle (CPA) tumors. Specifically, eleven of fifteen patients with large CPA tumors demonstrated contralateral ABRs for which wave IV and/or V were abnormal, while waves I and III were normal. In some cases, waves IV and/or V were absent, while in other cases one or both waves were delayed. The clinical interpretation for this type of ABR finding and the possible implications in relation to generator sites of the various ABR waves are discussed.