Auditory Brainstem Response Testing in Neurodiagnosis: Structure versus Function

This case report describes a 44-yr-old female referred by an outside facility who presented with progressive hearing loss in her left ear. Magnetic resonance imaging (MRI) results were normal, but a battery of audiological tests suggested neural hearing loss in the left ear. Following diagnosis of left neural hearing loss, the patient was successfully fit with a hearing aid on the left ear. This case report underlines the importance of using a battery of medical, radiologic, and audiological tests in the accurate determination of hearing loss site of lesion. Obvious retrocochlear dysfunction was revealed via auditory brainstem response (ABA) testing. MRI did not reveal underlying structural abnormality. Without the addition of the ABA to the diagnostic test battery, a cochlear hearing loss site of lesion would most likely have been diagnosed. Accurate diagnosis of hearing loss site of lesion is critical for patient counseling and treatment as well as for patient follow-up and monitoring.