Early predictors for later epilepsy after therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy.

BACKGROUND AND

OBJECTIVE

Therapeutic hypothermia (TH) is the standard of care for neonatal hypoxic-ischemic encephalopathy (HIE), yet the risk of neonatal epilepsy remains a significant burden for families and clinicians. We aimed to observe and describe clinical, electrographic, and neuroimaging factors associated with the development of epilepsy by age 2 years in neonates with HIE treated with TH.

METHODS

We conducted a retrospective observational study of neonates (≥36 weeks' gestational age) with moderate-to-severe HIE. Neonatal evaluations included clinical staging, continuous aEEG during a 72-hour cooling period and rewarming, and brain MRI (Weeke scoring). The primary outcome was the diagnosis of epilepsy (International League Against Epilepsy [ILAE] criteria) at 24 months of age.

RESULTS

Of 127 infants who completed follow-up, 15% (n = 19) developed epilepsy. Multivariate analysis revealed that only deep grey matter injury (Weeke score > 9.5; OR 101.8; 95% CI 6.39-399.6; p = 0.003) and persistent severe aEEG background suppression at 72 h (OR 25.4; 95% CI 1.57-740.2; p = 0.027) remained independent predictors. All patients with epilepsy had concurrent cerebral palsy (Gross Motor Function Classification System [GMFCS] > 3).

CONCLUSION

In the era of cooling, structural injury to the deep grey matter and failed aEEG recovery are robust early predictors of epilepsy in HIE. Identifying these factors early facilitates high-risk survivors receiving the intensive multidisciplinary surveillance they require.