Generalized periodic epileptiform discharges in critically ill children: clinical features, and outcome

Generalized periodic epileptiform discharges (GPDs) are a specific periodic EEG pattern, reported as having a poor clinical outcome. The incidence and clinical implications of this EEG pattern in children are not known. In this study, we examined the clinical features of children with GPDs.

EEG-video monitoring reports of children with critical illness in the intensive care unit were retrospectively reviewed to detect GPDs. The clinical history, hospital course and seizure characteristics were reviewed and outcome was based on the clinical findings at hospital discharge.

Twenty one children (age 2-18 years) were identified with GPDs. The most common underlying etiology was encephalitis (N=11). At the time of EEG, a continuous intravenous infusion (cIV) of an anticonvulsant drug was used to treat refractory status epilepticus (RSE). Non-convulsive seizures (NCS) were identified in 15, and clinical seizures in 13 children after GPDs were detected. GPDs occurred after a dose reduction in the cIV in 43%. Neuroimaging done in 16 children showed an acute change in 13/16 (81%) and chronic changes in 2/16 (13%). Five children (23%) died. Seven (33%) children had a favorable outcome, whereas the remaining children had a moderate to severe disability at the time of hospital discharge.

GPDs are seen during the course of RSE in critically ill children and are associated with seizure recurrence. A lower mortality rate occurs in children with GPDs compared to adult counterparts, likely related to different etiologies. Although the significance of GPDs must be determined within the context of the clinical situation, GPDs suggest a still active epileptic process.