Amplitude of the Brainstem Auditory Evoked Response: The Effect of Interstimulus Interval

Abstract

Brain electrical responses to auditory stimulation occur within 10 msec of stimulus presentation and are thought to represent the sequential activation of brainstem nuclei in the auditory pathway. These responses have been shown to be of diagnostic significance in detecting pathology within the brainstem. There is evidence that changing the interstimulus interval (i.e., rate of stimulation) may increase the sensitivity of the Brainstem Auditory Evoked Response (BAER) in the detection of brainstem disorders. The effect of changing the interstimulus interval from 100 to 10 msec upon the amplitude of the BAER was assessed in 11 young adults. BAER was found to be directly related to interstimulus interval (ISI) with the amplitude of waves I, II, and III decreasing with each decrease in ISI. Wave V amplitude initially increased and then decreased at the shortest ISIs.