Circadian variation in the latency of brainstem responses and its relation to body temperature.

The auditory brainstem response varies in a circadian rhythm that is negatively correlated with the circadian rhythm in oral temperature. The auditory brainstem responses and oral temperature were recorded every 3 hours from three healthy male subjects during a 2-day period. The data indicate that a reduction of 1 degree C in oral temperature is associated with an increase of 200 microseconds in the latency of wave V of the auditory brainstem response, and of 160 microseconds in the interval between waves I and V.