Brainstem auditory evoked responses that disappear during sleep: a possible manifestation of a neurogenic vestibular evoked response.

OBJECTIVE

To present a case of unilateral hearing loss in which a brainstem auditory evoked potential (BAEP) disappeared during sleep on the symptomatic side, and to argue that this may actually be a manifestation of a neurogenic vestibular evoked potential (NVESTEP).

MATERIAL AND METHOD: Brainstem auditory evoked potentials were performed in the standard manner.

RESULT: A poorly organized response was obtained during wakefulness on the symptomatic side that resembled a BAEP. The BAEP for the right ear was better organized. During sleep, the response for the left ear disappeared.

CONCLUSIONS

The poor organization of the response of the left ear compared to the right, and its disappearance during sleep, suggests that the response for the left ear was actually an NVESTEP and not a BAEP. The possibility of recording vestibular responses with auditory stimuli may have important implications for BAEP examinations performed during wakefulness that may lead to false negative results, in neonatal screening for hearing loss that use tone stimuli, and also in brain mapping using magnetic resonance imaging (MRI) and positron emission tomography (PET) relating to the auditory cortex.