Spike height improves prediction of future seizure risk

•Interictal epileptiform discharge (IED) characteristics improve prediction of seizure risk in patients with IEDs.•Increased spike height correlates with increased seizure risk.•Increased spike duration and increased slow wave rising and falling slopes may correlate with increased seizure risk. We evaluated whether interictal epileptiform discharge (IED) rate and morphological characteristics predict seizure risk. We evaluated 10 features from automatically detectable IEDs in a stereotyped population with self-limited epilepsy with centrotemporal spikes (SeLECTS). We tested whether the average value or the most extreme values from each feature predicted future seizure risk in cross-sectional and longitudinal models. 10,748 individual centrotemporal IEDs were analyzed from 59 subjects at 81 timepoints. In cross-sectional models, increases in average spike height, spike duration, slow wave rising slope, slow wave falling slope, and the most extreme values of slow wave rising slope each improved prediction of an increased risk of a future seizure compared to a model with age alone (p