EEG Monitoring Improves Outcomes for Newborn Seizures

Medscape Medical News from the Pediatric Academic Societies (PAS) and Asian Society for Pediatric Research (ASPR) Joint Meeting

(This coverage is not sanctioned by, nor a part of, the American Academy of Pediatrics, American Pediatric Society, Society for Pediatric Research, Academic Pediatric Association, or the Asian Society for Pediatric Research.)

May 12, 2014

VANCOUVER, British Columbia — For newborns with hypoxic-ischemic encephalopathy, time to treatment of seizures is less when electroencephalographic (EEG) monitoring is used rather than clinical monitoring, new research shows.

In addition, at 18- to 24-month follow-up, increased seizure burden was associated with worse developmental outcomes.

"We wanted to show that measuring seizures electrographically would lead to early detection, and by detecting them early, you can treat them sooner," said investigator Shamik Trivedi, MD, a fellow at the Washington University School of Medicine and the St. Louis Children's Hospital.

And if a patient has fewer seizures, it is hoped that outcomes will be better when the child is 2 years of age, he told Medscape Medical News.

Dr. Trivedi presented the research here at the Pediatric Academic Societies and Asian Society for Pediatric Research Joint Meeting.

The 69 infants involved in the study were at least 36 weeks of gestational age at birth and had moderate or severe hypoxic-ischemic encephalopathy. They were recruited in the first 12 hours after birth from 2007 and 2011.

Continuous EEG-video monitoring was performed for 72 hours. Infants were randomly assigned to receive clinical seizure treatment (CSG) or electrographic seizure treatment (ESG). The 2 groups were similar with respect to severity of hypoxic-ischemic encephalopathy, treatment with hypothermia, gestational age, birth weight, sex, age, duration of EEG monitoring, phenobarbital levels, and number of antiseizure drugs used.

At 7 to 10 days, all infants underwent MRI. All surviving infants were assessed with the Bayley Scales of Infant and Toddler Development-III at 18 to 24 months. The researchers calculated time to seizure treatment from detection and cumulative seizure burden.

EEG seizures occurred in 15 of the 37 infants in the ESG group and in 20 of the 32 in the CSG group. Electrographic seizure burden was lower in the ESG group than in the CSG group after adjustment for MRI injury (5.9 vs 7.6; P = .02).

It's important to treat the entire burden of seizures, as opposed to just the seizures that we can see.

Dr. M.J. Harbert

The time from the onset of electrographic seizures to treatment was lower in the ESG group than in the CSG group (P = .01).

Of the 35 neonates who experienced seizures, 27 completed follow-up (6 died and 2 became ineligible). Follow-up results were available for 24 infants (8 in the ESG group and 16 in the CSG group).

The 2 groups had no differences in cognitive (P = .2), motor (P = .06), or language (P = .4) scores, but the cumulative seizure burden in the 24 subjects correlated with worse outcomes in cognitive (P = .003), motor (P = .01), and language (P = .03) domains, as well as severity of MRI injury (P = .01).

"There's a large push, from data seen in this and other studies, for the use of EEG monitoring. We know that seizures are subclinical most of the time," said Dr. Trivedi, who isn't ready to make clinical recommendations on the basis of the study outcomes. "If we had a larger group to truly compare EEG seizures with clinical seizures and the outcomes, that could have an effect on clinical management in the future."

Evidence has shown that the longer seizures go on, "the harder they are to treat," said M.J. Harbert, MD, director of neonatal neurology at the University of California at San Diego. "They are correlated with increased cell death at autopsy, and even, in some cases, remodeling and reorganization of connections."

"The standard of care in this arena is changing very rapidly," said Dr. Harbert. "It's important to treat the entire burden of seizures, as opposed to just the seizures that we can see by looking at a baby.

This study showed that seizure burden is directly correlated with poorer outcomes. "It had been shown before, but perhaps not as comprehensively as it should," Dr. Harbert said.

Dr. Trivedi and Dr. Harbert have disclosed no relevant financial relationships.

Pediatric Academic Societies (PAS) and Asian Society for Pediatric Research (ASPR) Joint Meeting: Abstract 2823.5. Presented May 4, 2014.