Cerebral Metabolism During Electrically Induced Seizures in Man

Abstract

DURING convulsions, cerebral metabolism increases and the brain's need for oxygen and substrate rises.^1,2At the same time, respiration ceases and this plus the intense muscle activity of the convulsion results in arterial blood hypoxia. To meet the increased metabolic demands of cerebral seizures, cerebral vessels dilate, systemic blood pressure increases,³and cerebral blood flow rises.^1,4,5However, these compensating mechanisms cannot prevent brain hypoxia if the arterial blood is desaturated and, as a result, during a generalized convulsion cerebral venous and cortical oxygen tension decrease,⁶cerebral energy stores are depleted,^6,7and brain lactate rises.^6,7 The present study was undertaken to determine whether the compensatory increase in cerebral blood flow can protect the human brain against hypoxia during a cerebral seizure if apnea and muscle movement are eliminated. The study was begun after a previous study suggested that cerebral hypoxia does not occur during