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Neuropediatrics 2024; 55(01): 032-041
DOI: 10.1055/a-2190-9521
Original Article

Distinctive Amplitude-Integrated EEG Ictal Pattern and Targeted Therapy with Carbamazepine in KCNQ2 and KCNQ3 Neonatal Epilepsy: A Case Series

Ana Vilan
1   Department of Neonatology, Centro Hospitalar São João, Faculty of Medicine, University of Porto, Porto, Portugal
,
Ana Grangeia
2   Department of Genetics, Centro Hospitalar São João, Faculty of Medicine, University of Porto, Porto, Portugal
,
José Mendes Ribeiro
3   Laboratory of Clinical Neurophysiology, Department of Neurology, Centro Hospitalar Vila Nova de Gaia e Espinho, Porto, Portugal
,
Maria Roberta Cilio
4   Division of Pediatric Neurology, Department of Pediatrics, Catholic University of Louvain, Brussels, Belgium
,
Linda S. de Vries
5   Department of Neonatology, Leiden University Medical Center, Leiden, The Netherlands
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Abstract

Background Carbamazepine (CBZ) is effective in treating KCNQ2/3-related seizures, which may present with a distinctive amplitude-integrated electroencephalography (aEEG) pattern.

Objective To assess how improved recognition of the distinctive aEEG ictal pattern associated with KCNQ2/3 variants has enabled early and effective targeted therapy with CBZ.

Methods Retrospective descriptive study of five neonates with KCNQ2/3 pathogenic gene variants admitted at a level 3 neonatal intensive care unit (NICU) over an 8-year period.

Results The distinctive ictal aEEG pattern was recognized in four neonates after an average of 61.5 hours (minimum 12 hours, maximum 120 hours) from the first electroclinical seizure and prompted the use of CBZ that was effective in all. The two most recently diagnosed patients could avoid polytherapy as they received CBZ as the first and second antiseizure medication, respectively. Three out of five patients with continuous normal voltage (CNV), sleep–wake cycling (SWC), and shorter postictal suppression had normal neurodevelopmental outcome. Regarding the remaining two infants, one was not trialed with CBZ and had a high seizure burden, both presented with a prolonged postictal suppression, no SWC, and had moderate-to-severe developmental delay. Genetic results became available after the neonatal period in all but one of the infants, who had a prenatal diagnosis.

Conclusion Recognition of the distinctive ictal aEEG pattern in the NICU allowed early and effective targeted therapy with CBZ in four neonates, well before genetic results became available. Furthermore, a CNV background pattern with SWC and short postictal suppression were associated with normal developmental outcomes.

Keywords

KCNQ2 - KCNQ3 - neonatal seizures - amplitude-integrated EEG - carbamazepine - postictal suppression


Publication History

Received: 19 July 2023

Accepted: 11 October 2023

Accepted Manuscript online:
12 October 2023

Article published online:
07 November 2023

© 2023. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

 

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