SOMATOSENSORY CEREBRAL EVOKED POTENTIALS AFTER VASCULAR LESIONS OF THE BRAIN-STEM AND DIENCEPHALON

Abstract

Clinical and electrophysiological observations are described in 7 patients with clinically well identified vascular lesions of the brain stem or diencephalon. In the patients with a thalamic syndrome, the somatosensory cerebral evoked potentials had a reduced voltage and increased latency on the affected side. No significant anomalies were recorded in the patients with a Wallenberg or Weber syndrome. In patients with a locked in syndrome, the cerebral evoked potentials presented marked bilateral anomalies which provided interesting data about the extension of the pontine vascular lesions into the tegmentum. The pathophysiological mechanisms involved in the changes of average cerebral evoked potentials and in the slowing of corticipetal conduction are discussed.