Brainstem Auditory Evoked Potentials

Synonyms

Auditory brainstem response, ABR; Brainstem auditory evoked response, BAER

Definition

Brainstem Auditory Evoked Potentials (BAEP) are low-amplitude electrical voltage potentials in the brain that are evoked by a sound, often a click, and recorded using electrodes on the scalp (i.e., electroencephalography or EEG). Since the potentials typically have an amplitude around 1 mV, hundreds of trials are averaged together to provide data with adequate signal to noise ratio. BAEPs have been used as a tool to examine brainstem integrity and hearing ability clinically since the 1970s, helping to diagnose tumors and other diseases such as multiple sclerosis. BAEPs are particularly useful with patients who are difficult to test by traditional audiometry, where feedback is required, because of compromised levels of consciousness, limited communication, or behavioral noncompliance. BAEPs are also useful for detecting subtle changes that may be clinically relevant, and localizing the...