Brain cooling reduces the risk of postneonatal epilepsy in newborns affected by moderate to severe hypoxic-ischemic encephalopathy

BACKGROUND: Neonatal hypoxic-ischemic encephalopathy is still a significant cause of neonatal death and neurodevelopmental disabilities, such as cerebral palsy, mental delay, and epilepsy. After the introduction of therapeutic hypothermia, the prognosis of hypoxic-ischemic encephalopathy has improved, with reduction of death and disabilities. However, few studies evaluated whether hypothermia affects rate and severity of postneonatal epilepsy. We evaluated rates, characteristics and prognostic markers of postneonatal epilepsy in infants with moderate to severe hypoxic-ischemic encephalopathy treated or not with therapeutic hypothermia. METHODS: We analyzed clinical data, EEG recordings, cerebral Magnetic Resonance Imaging (MRI) and outcome in 23 cooled and 26 non-cooled asphyxiated neonates (>= 36 weeks' gestation), admitted from 2004 to 2012. RESULTS: Among 49 neonates 11 (22%) had postneonatal epilepsy, of which 9 (18%) were non-cooled and 2 (4%) were cooled (P=0.05). Six of 11 infants (55%) had West syndrome, 4 (36%) had focal epilepsy and 1 (9%) had Lennox-Gastaut Syndrome. At multiple logistic regression analysis MRI pattern significantly correlated with postneonatal epilepsy (OR 0.19, 95% CI 0.04-0.88, P=0.03). Extensive lesions in basal ganglia and thalami plus cortical and white matter were associated with postneonatal epilepsy. CONCLUSIONS: Only perinatal asphyxia with extensive lesions in basal ganglia and thalami plus cortical and white matter lesion conveys a high risk for early and severe postneonatal epilepsy. Moreover, therapeutic hypothermia is associated with a decrease of the risk of developing postneonatal epilepsy.

Automated summary

Severe neonatal hypoxic-ischemic encephalopathy with extensive lesions in basal ganglia and thalami plus cortical and white matter lesions carries a high risk for early and severe postneonatal epilepsy. Furthermore, therapeutic hypothermia is associated with a decreased risk of developing postneonatal epilepsy.