Auditory brainstem response with high stimulus rates in normal and patient populations.

Normative data were collected on 48 subjects to determine the effects of increasing stimulus rates on the auditory brainstem response. These subjects were then compared to 221 patients referred for otoneurologic evaluation. The 90 patients with impaired auditory sensitivity demonstrated significantly less wave V latency shift than either the 131 patients with normal auditory sensitivity or the normal subjects. The incidence of abnormal wave V latency shift was 12% in the patients with normal auditory sensitivity and 8% in the patients with impaired auditory sensitivity. The high stimulus rate was often the only ABR parameter indicative of brainstem involvement in patients with documented CNS pathology. The authors conclude that a high stimulus rate contributes to the diagnosis of brainstem pathology often enough to warrant its routine use.