Aging effects on brainstem auditory evoked potentials.

Since age effects on central conduction time in the acoustic pathway are still debated, we recorded brainstem auditory evoked potentials in 154 normoacoustic subjects, with no history of neurologic or otologic pathology. Linear regression has been used for statistical analysis. Data obtained show an age-related prolongation of latency values which is particularly marked for wave I, while other waves (particularly wave III) do not show a significant change. Thus, interpeak latency (IPL) values do not increase with increasing age: in particular IPLs I-II and I-III decrease, showing a negative "r" value, and IPLs I-V and II-V (which is to be considered the true "central conduction time" through the acoustic pathway) do not show a significant change. Our data seem to demonstrate that the aging process is essentially a peripheral phenomenon which does not involve the central part of the acoustic pathway.