[Evoked potentials in diagnosis of ischemic brain stem lesions]

We present an overview on the impact of evoked potentials in diagnosis of ischemic brainstem lesions. Brainstem auditory evoked potentials and somatosensory evoked potentials depict abnormalities, whereas visual evoked potentials are normal in most cases. In patients with basilar artery thrombosis and primary pontine hemorrhage these evoked potentials are mostly abnormal and can indicate the location of the lesion. Furthermore, they are of prognostic value. Whether evoked potentials are abnormal in strokes with branch occlusion of the basilar artery, depends on the location of the infarction. In infarctions of the basis pontis BAEP and SEP may be normal. Hemiparesis in brainstem strokes are associated with abnormalities in transcranial magnetic stimulation. However, no further evaluation of the level of the pyramidal tract lesion is possible by this method. During fibrinolytic therapy of basilar artery thrombosis a continuous monitoring is possible by means of BAEP. Thus, information can be obtained that is not available from neurological examination of the patient under sedative drugs.