A Distinctive Ictal Amplitude-Integrated Electroencephalography Pattern in Newborns with Neonatal Epilepsy Associated with KCNQ2 Mutations

Abstract

Background: Recurrent and prolonged seizures are harmful for the developing brain, emphasizing the importance of early seizure recognition and effective therapy. Amplitude-integrated electroencephalography (aEEG) has become a valuable tool to diagnose epileptic seizures, and, in parallel, genetic etiologies are increasingly being recognized, changing the paradigm of the workup and management of neonatal seizures.

Objective: To report the ictal aEEG pattern in neonates with KCNQ2-related epilepsy.

Subjects and methods: In this multicenter descriptive study, clinical data and aEEG findings of 9 newborns with KCNQ2 mutations are reported.

Results: Refractory seizures occurred in the early neonatal period with similar seizure type, including tonic features, apnea, and desaturation. A distinct aEEG seizure pattern, consisting of a sudden rise of the lower and upper margin of the aEEG, followed by a marked depression of the aEEG amplitude, was found in 8 of the 9 patients. Prompt recognition of this pattern led to early treatment with carbamazepine in the 2 most recent cases.

Conclusion: Early recognition of the electroclinical phenotype by using aEEG may direct genetic testing and a precision medicine approach with sodium channel blockers in neonates with KCNQ2 mutations.

Keywords: Amplitude-integrated electroencephalography; Carbamazepine; KCNQ2 mutations; KCNQ2-related epilepsy; Neonatal seizures.