Coma mechanisms

A physiologic classification of cerebral metabolic disturbances is presented, based on the premise that energy required for functional activity and structural integrity of cerebral cells results from enzymatically catalyzed reactions between glucose and oxygen. Insufficiency of glucose (preferential substrate of the cerebral cells) or oxygen, or inhibition or lack of essential enzymes necessary for the degradation of glucose will result in cerebral metabolic disturbances. The variable response of the central nervous system to the deprivation of these essential substances is believed to be due to their availability and differential rates of utilization by various areas of the central nervous system. Clinical examples along with observations of cerebral hemodynamics and metabolism of representative disturbances for each group are presented wherever possible.