EEG monitoring should be continued in infants at risk of seizures during rewarming

Study results published in JAMA Neurology show higher odds of seizures during rewarming correlate with death or disability at 2 years in infants at risk, demonstrating the need for EEG monitoring during rewarming.

“This study is telling us that there’s an untapped opportunity to improve outcomes by making EEG or amplitude EEG monitoring a standard part of the cooling and rewarming protocol,” Lina Chalak, MD, MSCS, from the University of Texas Southwestern Medical Center, told Healio Neurology.

Chalak and colleagues enrolled 364 infants in the Optimizing Cooling multicenter Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network trial from December 2011 to December 2013, of which 120 infants were followed for 2 years. Complete data for death or disability were available for 112 infants. Sixty-six infants were randomly assigned to either 72 hours of cooling (group A) and 54 to 120 hours (group B). The mean standard deviation gestational age was 39 weeks.

Two central amplitude-integrated EEG readers blinded to treatment arm and rewarming epoch compared serial amplitude electroencephalography recordings in the 12 hours before and 12 hours during rewarming for evidence of electrographic seizure activity. After the adjustment for center, prior seizures, depth of cooling and encephalopathy severity, ORs and 95% CIs were assessed.

The occurrence of electrographic seizures during rewarming initiated at 72 or 120 hours compared with the preceding 12-hour epoch served as the primary outcome. Other outcomes included death or moderate or severe disability at age 18 to 22 months.

In the detection of seizures, Chalak and colleagues noted an interrater agreement. Electrographic seizures were observed in more infants during the rewarming epoch compared with the preceding epoch (group A, 27% vs. 14%; P = .001; group B, 21% vs. 10%; P = .03). Investigators said during rewarming, the adjusted ORs for seizure frequency were 2.7 for group A and 3.2 for group B.

According to researchers, at 2 years, after the adjustment for baseline clinical encephalopathy and seizures as well as center, the composite death or moderate-to-severe disability outcome was higher in infants with electrographic seizures during rewarming (RR = 1.7, 95% CI, 1.25-2.37).