Cerebral Death and the Electroencephalogram

A questionnaire sent to members of the American Electroencephalographic Society disclosed that of 1,665 patients reported to have isoelectric electroencephalograms there were only three with truly linear records who recovered some cerebral function. Two of these had barbiturate-induced coma and one had coma due to a meprobamate overdose. From correspondence with foreign colleagues and critical review of the literature and the questionnaires, the committee concluded that, except for anesthetic drug levels or hibernation, electrocerebral silence together with the neurologic characteristics of unreactive coma, absence of striated muscle activity, and total absence of reflexes is strong presumptive evidence of irreversible coma (cerebral death). Opinions differ as to the time limit for reversibility in relation to different causes; 24 hours was usually accepted. Technical recommendations stressed use of increased instrumental sensitivity.