Brainstem Auditory Evoked Responses In Brainstem Stroke

Abstract

Brainstem auditory evoked responses (BAERs) were studied in eighteen patients with brainstem strokes, and the results were correlated with the clinical and radiological localization. The absence of all ipsilateral waves (or all except wave I) was caused by acute, relatively extensive lesions impinging on the inferolateral part of the pons. The late wave abnormalities (III-V delay or poor wave V formation) which more often occurred on the contralateral side of the lesions, generally resulted from dorsally situated pontomesencephalic lesions. The pontomesecephalic lesions sparing dorsal or inferolateral areas as well as medullary lesions tended to produce normal BAERs. We conclude that BAER is an effective clinical aid in localizing braintem stroke if it is interpreted with respect to the three dimensional brainstem auditory pathway.