Characterising seizure cycles in pediatric epilepsy

Hannah Kamitakahara; Philippa J Karoly; Rachel E Stirling; Ewan S Nurse; Gabriel Dabscheck; Dean Freestone; Mark J Cook; Wendyl D'Souza; Jodie Naim-Feil

doi:10.1016/j.yebeh.2025.110507

Characterising seizure cycles in pediatric epilepsy

Epilepsy Behav. 2025 May 30:172:110507. doi: 10.1016/j.yebeh.2025.110507. Online ahead of print.

Authors

Hannah Kamitakahara¹, Philippa J Karoly², Rachel E Stirling², Ewan S Nurse³, Gabriel Dabscheck⁴, Dean Freestone⁵, Mark J Cook⁶, Wendyl D'Souza⁷, Jodie Naim-Feil⁸

Affiliations

¹ Seer Medical Pty Ltd, VIC, Australia.
² Graeme Clark Institute and Department of Biomedical Engineering, The University of Melbourne, VIC, Australia.
³ Seer Medical Pty Ltd, VIC, Australia; Graeme Clark Institute and Department of Biomedical Engineering, The University of Melbourne, VIC, Australia; Department of Medicine, St Vincent's Hospital Melbourne, The University of Melbourne, VIC, Australia.
⁴ Seer Medical Pty Ltd, VIC, Australia; Murdoch Children's Research Institute, Parkville, VIC, Australia; Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, VIC, Australia; The Royal Children's Hospital, Parkville, VIC, Australia.
⁵ Seer Medical Pty Ltd, VIC, Australia; Graeme Clark Institute and Department of Biomedical Engineering, The University of Melbourne, VIC, Australia.
⁶ Graeme Clark Institute and Department of Biomedical Engineering, The University of Melbourne, VIC, Australia; Department of Medicine, St Vincent's Hospital Melbourne, The University of Melbourne, VIC, Australia.
⁷ Department of Medicine, St Vincent's Hospital Melbourne, The University of Melbourne, VIC, Australia.
⁸ Graeme Clark Institute and Department of Biomedical Engineering, The University of Melbourne, VIC, Australia. Electronic address: jodie.feil@unimelb.edu.au.

PMID: 40449068
DOI: 10.1016/j.yebeh.2025.110507

Abstract

Background: Multiday cyclic patterns underlying the timing of seizures are well-established in adults with epilepsy. However, longer-term patterns underpinning these models are yet to be explored extensively in pediatric cohorts. This study aims to identify and compare multiday seizure cycles between pediatric and adult cohorts, followed by a preliminary validation of cycle-based methods for estimating seizure likelihood in a pediatric cohort.

Methods: Multiday seizure cycles were extracted retrospectively from 325 (71 pediatric) electronic seizure diary users with confirmed epilepsy. Cycles were grouped (k-means clustering) and seizure cycles quantified (synchronisation index) with significant cycles identified (Rayleigh test (p < 0.05)). Wilcoxon rank-sum test assessed differences in prevalence and strength of cycle groups between pediatric and adult cohorts. The accuracy of cycle-based models to track pediatric seizure occurrence was calculated from the receiver operating characteristic (area under the curve; AUC) comparing estimated cycles to shuffled surrogate data and further validated with a moving average model.

Findings: 30,019 seizures (pediatric: Median = 51, IQR (Q1 = 30, Q3 = 115), Range (21-661), adult: Median = 46, IQR (Q1 = 31, Q3 = 93), Range (20-1112) were analysed and seizure cycles grouped across circadian (0.5-1.5 days), about-weekly (2-12 days), about-fortnightly (13-22 days) and about-monthly (23-32 days) periodicities. Significant cycles were identified in each cycle group, with no differences in prevalence or cycle strength between pediatric and adult cohorts. Estimated cycles showed a reliable assessment of observed seizure occurrence (significantly (p < 0.05) better performance compared to random models for 88% (44 of 50) and moving average models for 50% (25 of 50) of observed daily seizure occurrence).

Significance: Multiday seizure cycles estimated from seizure diaries present a viable model for identifying longer-term seizure patterns in a pediatric cohort. Knowledge of these individual seizure cycles has potential to reduce the unpredictability of seizure timing and inform clinical decision-making.

Keywords: Epilepsy management; Multiday rhythms; Pediatric epilepsy; Seizure cycles.