Qualitative and quantitative analysis of epileptic seizures in neonates with moderate and severe hypoxic-ischemic encephalopathy undergoing therapeutic hypothermia

*Correspondence: [e-mail].

Abstract

Background: Epileptic seizures are the most common neurological emergency in the neonatal period and one of its main causes is hypoxic-ischemic encephalopathy. The diagnosis of seizures is difficult, particularly in critically ill newborns in an intensive care setting. In addition, many newborns will have mainly or exclusively electrographic seizures, configuring the importance of the electroencephalogram (EEG), amplitude-integrated EEG (aEEG) and video EEG in the identification and treatment of these events.

Objective: Qualitative and quantitative analysis of epileptic seizures in neonates with moderate and severe hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH).

Methods: Retrospective observational study, carried out in a neurological referral neonatal intensive care unit in São Paulo. Neonates with moderate and severe HIE were selected, undergoing TH between 2018 and 2022. Neonatal seizures were evaluated with aEEG associated with crude EEG, video image (vídeo aEEG) and experienced clinical staff throughout the TH protocol. Modified Sarnat and Sarnat Scale was used for clinical assessment of patient’s neurological impairment.

Results: We reviewed 128 cases. Regarding the qualitative analysis of epileptic seizures, 31 patients (24%) had neonatal seizures. Of these, 5 (16%) of the newborns had clinical seizures and in 26 patients (84%) electrographic-only seizures were identified. In the quantitative analysis of the 31 patients who had neonatal seizures, 10 seizures (32%) have occurred on isolation way whether clinical or electrographic. However, the seizures have recurred in 21 patients (68%). Regarding therapy, 30 patients (97%) with present epileptic activity received antiseizure medication. 8 patients (26%) even received two medications. In 2 patients (6%), a third antiseizure was used and only 1 patient in the study (3%) was medicated with 4 antiseizure, not necessarily concomitantly.

Conclusion: The study found that 84% of patients with moderate and severe hypoxic-ischemic encephalopathy undergoing therapeutic hypothermia had electrographic seizures. We also found that most patients had more than one crisis. In this sense, we highlight the importance of continuous electrographic monitoring in the management of these patients and consequent improvement in neurological prognosis

Publication History

Article published online:
12 May 2025