Prevalence of Interictal Epileptiform Discharges in Children Less Than One Year of Age Referred for Polysomnography.

ABSTRACT

This study aimed to identify the prevalence of interictal epileptiform discharges (IEDs) in patients less than one year of age referred for polysomnogram (PSG), to quantify the number of IEDs and characterize sleep stage(s) during which IEDs occur, and to relate the reason for PSG referral and IED frequency. This was a retrospective cohort study of children less than 12 months of age referred for PSG studies. Fifty study participants had sufficient EEG data, and 49 were included in the study analysis. We identified an IED prevalence rate of 28% over the 2-year study period. The mean number (Standard Deviation; SD) of IEDs per hour of total sleep time was 0.4 (1.2). IEDs occurred most frequently in non-rapid eye movement (NREM) stages 2 and 3 of sleep. The most common reason for PSG referral in this patient cohort was for obstructive sleep apnea (OSA) (42/50). We concluded that patients less than 12 months of age referred for PSG may have abnormal brain activity. The relationship of that activity to PSG findings is unclear. This study offers a systematic process of identifying IEDs that should prompt referral to a neurologist for further evaluation.