Auditory evoked potentials (AEP)

Brainstem auditory evoked potentials (AEP), also called BAEP (brainstem auditory evoked potentials), record the electrical responses generated by the auditory pathways in response to a sound stimulation (clicks or tone bursts). The examination records a series of waves (I to V), each of which corresponds to a precise anatomical relay of the auditory pathways, from the cochlear nerve to the inferior colliculus. Wave I is generated by the cochlear nerve, wave III by the superior olivary nuclei of the brainstem, and wave V by the inferior colliculus (midbrain). The analysis of the absolute latencies of each wave and of the inter-wave intervals makes it possible to localise a condition along the central auditory pathways, from the auditory nerve to the brainstem. AEP are particularly useful in the diagnosis of acoustic neuromas (vestibular schwannoma), where a lengthening of the I-III interval is typically observed. They are also essential in the screening of neonatal deafness, because they allow an objective assessment of hearing without requiring the cooperation of the patient. The Clinique Pasteur in Tunis has efficient AEP equipment, allowing a precise assessment of the electrophysiological hearing threshold and of the integrity of the central auditory pathways.