Lateralization of brainstem lesions by brainstem auditory evoked potentials.
In eight patients with unilateral pontine and midbrain lesions, brainstem auditory evoked potentials (BAEPs) were studied with ipsilateral (Cz-Ai) and contralateral (Cz-Ac) recordings after monaural stimulation. In all cases, the most prominent abnormality was noted in BAEP generated by stimulating the ear ipsilateral to the lesions. The Cz-Ai and Cz-Ac patterns showed similar abnormalities in five of the patients and dissociated abnormalities in two patients. We conclude that: (1) Lateralization of BAEP is possible in unilateral pontine and midbrain lesions. (2) Monaural stimulation with Cz-Ai and Cz-Ac recordings is essential for lateralization. (3) The BAEP in monaural stimulation is predominantly generated from the auditory structures ipsilateral to the stimulated ear.
D001927:Brain Diseases / Q000175:diagnosis*; D001932:Brain Neoplasms / Q000175:diagnosis; D001933:Brain Stem / Q000098:blood supply; D002544:Cerebral Infarction / Q000175:diagnosis; D005072:Evoked Potentials, Auditory; D006801:Humans; D008526:Medulla Oblongata / Q000098:blood supply; D008636:Mesencephalon / Q000098:blood supply; D011149:Pons / Q000098:blood supply; D011930:Reaction Time / Q000502:physiology