Abstracts

Rationale: Therapeutic hypothermia (TH) recently became standard of care for newborns with hypoxic-ischemic encephalopathy (HIE). While the presence of seizures has been associated with poor neurodevelopmental outcome in infants with HIE, recent studies, conducted in newborns treated with TH, suggest that the outcome after seizures is not uniformly poor. Aim: To study the association between seizures during TH and neurodevelopmental outcome in newborn with HIE. Methods: Consecutive newborns who underwent whole body cooling at Bambino Ges Children s Hospital between March 2009 and March 2013 were monitored with continuous video-EEG during TH and rewarming. Criteria for TH were based on those used in randomized controlled trial. Electrographic seizures were treated with antiepileptic drugs according to institutional guidelines. Clinical events without EEG correlate were not considered. Full video-EEG recording were analyzed for seizures and status epilepticus (SE). MRI was performed shortly after rewarming and after 6 months. Injury was scored as none-mild or severe (Barkovich et al., AJNR, 1998). Neurodevelopmental outcome was assessed at 6 months of age by using Gross Motor Function Measure (GMFM-88), and Griffiths Mental Development Scale (GMDS). Results: 29 patients (13 males) completed a full 72 hours TH with continuous video-EEG monitoring. Electrographic seizures were identified in 15/29 (52%) patients: 8 (53%) presented with isolated or recurrent seizures and 7 (47%) had status SE. 11/15 patients (73.5%) never showed a clinical correlate during seizures, including 4 with subclinical SE. One infant with SE died prior to MRI. 9/14 (64%) had none or mild MRI injury while moderate/severe MRI injury was observed in 5 infants (36%) after rewarming. Two infants, who had had SE during TH, subsequently died. Two patients were lost to follow-up. 11/14 (78,5%) infants with seizures during TH had a mean follow-up of 13 months (range 6 -24). At follow-up 9/11 (82%) patients showed a normal neurological examination, a psychomotor development appropriated for age, as well as normal MRI. Seven of them (63.5%) had isolated or recurrent seizures and four (36.5%) had SE. 2/11 (18%) patients had an abnormal neurodevelopmental outcome (1 mild and 1 severe disability): both of them had had SE. Although no antiepileptic drugs were given beyond the neonatal period, none had seizure recurrence subsequently.Conclusions: While seizures were frequently observed in our cohort, most infants had a normal neurodevelopmental outcome and none of them developed epilepsy. Although abnormal neurodevelopmental outcome was only seen in infants with neonatal SE, the prognosis is not uniformly poor. Our findings suggest that treatment with hypothermia may improve the outcome after neonatal seizures in infants with HIE.