Electrographic seizures after convulsive status epilepticus in children and young adults: A retrospective multicenter study

Iván Sánchez Fernández, Children's Hospital Boston
Nicholas S. Abend, University of Pennsylvania
Daniel H. Arndt, Oakland University William Beaumont School of Medicine
Jessica L. Carpenter, Childrens National Health System
Kevin E. Chapman, University of Colorado School of Medicine
Karen M. Cornett, Duke University School of Medicine
Dennis J. Dlugos, University of Pennsylvania
William B. Gallentine, Duke University School of Medicine
Christopher C. Giza, David Geffen School of Medicine at UCLA
Joshua L. Goldstein, Northwestern University Feinberg School of Medicine
Cecil D. Hahn, Hospital for Sick Children University of Toronto
Jason T. Lerner, David Geffen School of Medicine at UCLA
Joyce H. Matsumoto, David Geffen School of Medicine at UCLA
Kristin McBain, Hospital for Sick Children University of Toronto
Kendall B. Nash, University of California, San Francisco
Eric Payne, Hospital for Sick Children University of Toronto
Sarah M. Sánchez, University of Pennsylvania
Korwyn Williams, University of Arizona College of Medicine – Phoenix
Tobias Loddenkemper, Children's Hospital Boston

Abstract

Objective To describe the prevalence, characteristics, and predictors of electrographic seizures after convulsive status epilepticus (CSE). Study design This was a multicenter retrospective study in which we describe clinical and electroencephalographic (EEG) features of children (1 month to 21 years) with CSE who underwent continuous EEG monitoring. Results Ninety-eight children (53 males) with CSE (median age of 5 years) underwent subsequent continuous EEG monitoring after CSE. Electrographic seizures (with or without clinical correlate) were identified in 32 subjects (33%). Eleven subjects (34.4%) had electrographic-only seizures, 17 subjects (53.1%) had electroclinical seizures, and 4 subjects (12.5%) had an unknown clinical correlate. Of the 32 subjects with electrographic seizures, 15 subjects (46.9%) had electrographic status epilepticus. Factors associated with the occurrence of electrographic seizures after CSE were a previous diagnosis of epilepsy (P =.029) and the presence of interictal epileptiform discharges (P <.0005). The median (p 25-p75) duration of stay in the pediatric intensive care unit was longer for children with electrographic seizures than for children without electrographic seizures (9.5 [3-22.5] vs 2 [2-5] days, Wilcoxon test, Z = 3.916, P =.0001). Four children (4.1%) died before leaving the hospital, and we could not identify a relationship between death and the presence or absence of electrographic seizures. Conclusions After CSE, one-third of children who underwent EEG monitoring experienced electrographic seizures, and among these, one-third experienced entirely electrographic-only seizures. A previous diagnosis of epilepsy and the presence of interictal epileptiform discharges were risk factors for electrographic seizures.