BRAIN-STEM AUDITORY EVOKED-RESPONSES IN BRAIN-STEM INFARCTION

Brainstem auditory evoked responses (BAER) were recoreded in 40 patients with clinically definite brainstem infarction; results were compared to localizations from physical signs and CT [computer tomographic] scans. The BAER was abnormal in 92% of patients with evidence on physical examination of dysfunction of lateral structures in the pons or midbrain. Normal BAER were seen with medially-situated or medullary lesions. When both rostrocaudal level and lateralization were considered, the BAER indicated damage in additional areas not evident on physical examination in 25% of patients. However, physical signs indicated damage in areas not reflected by the BAER in 22% of patients. Therefore, the BAER complements the localization obtained from physical findings. BAER were abnormal in more of these patients than were CT scans and thus are useful for confirmation of bedside impressions.