Detection of neurological damage during cardiopulmonary bypass

Three cases of neurological damage, which occurred during cardiopulmonary bypass, and which were detected by the cerebral function analysing monitor, are reported. A fourth case, which had similar changes on the cerebral function analysing monitor but no neurological damage, is also described. The importance of changes in frequency of the cerebral electrical activity in the early detection and accurate prediction of severity of neurological damage is emphasised. The advantages of this instrument over other displays of the electroencephalogram are discussed.