QUANTITATIVE EEG BEFORE AND AFTER OPEN-HEART-SURGERY IN CHILDREN - A SIGNIFICANT DECREASE IN THE BETA AND ALPHA(2) BANDS POSTOPERATIVELY

Quantitative EEGs of 30 patients undergoing open heart surgery were investigated before, 6 days, 11 days and 44 days after operation. The study was conducted in order to investigate whether quantitative EEGs can show postoperative changes in children after open heart surgery. In 28 children, no new neurological signs of cerebral involvement were seen postoperatively. The most striking feature in these children was a significant decrease in the beta and the alpha2 bands 6 and 11 days postoperatively. The pattern in the delta band was dominated by an increase 6 days postoperatively. Except for a slight decrease in alpha2 waves, all variables were restored to preoperative values at 44 days after the operation. We found a significant decrease in plasma sodium and chloride after surgery but children with no or slight declines (1-3 mmol/1) also showed increased slow activity postoperatively. Therefore we conclude that an organic brain syndrome, although usually mild and transient, is a general phenomenon after open heart surgery.