Use of TEOAE, ABR, and Acoustic Reflex Measures to Assess Auditory Function Patients With Acoustic Neuroma.

Cochlear and neural auditory function for a series of 30 patients with acoustic neuroma was assessed pre- and postoperatively by transiently evoked otoacoustic emission (TEOAE), auditory brain stem response (ABR), and acoustic reflex measures. Employing a retrosigmoid surgical approach, physical integrity of the acoustic nerve was preserved for 22 patients. TEOAEs were observed preoperatively for 13 patients and postoperatively for 6 of them. Postoperative neural function remained unchanged or improved following surgery for 7 patients, and cochlear function decreased. TEOAE, ABR, and acoustic reflex measurements were considered valuable in providing information about site of lesion and probable mechanisms of injury associated with tumor removal.