Normal brain stem auditory evoked potentials recorded in sleep apneics during waking and as a function of arterial oxygen saturation during sleep.

Brain stem auditory evoked potentials (BAEPs) can be utilized as an index of neuronal dysfunction at the level of the brain stem. These waves are known to be independent of level of arousal. In the present study, BAEPs (waves I-V) to monaural click stimulation were recorded during daytime waking and as a function of arterial oxygen saturation during nocturnal sleep in 6 subjects with obstructive sleep apnea syndrome. Normal conduction times were recorded in all 6 subjects during daytime waking. In addition, BAEPs remained stable in every case during sleep-related apneas when averaged over intervals of arterial oxygen saturation as low as 45-70% in one subject. Our data indicate that (1) the repetitive oxygen desaturation experienced during sleep in apneics had neither acute nor chronic, measurable effects on neurons which subserve the BAEP, and (2) a brain stem abnormality involving the structures which subserve the BAEP does not underly obstructive sleep apnea.