Quantitative characteristics of spike-wave paroxysms in genetic generalized epilepsy

To characterize generalized spike-wave paroxysms (GSW) in children with generalized genetic epilepsy (GGE).

We annotated 15-19 channel scalp EEGs from a retrospective cohort from patients with a variety of GGE syndromes. Connectivity, entropy, frequency, power, spike-amplitudes were compared with a normal baseline activity and analyzed for the effect of age and sex. Cluster analysis was used to group spike-topographies between patients.

In total, 864 GSWs from 100 patients aged 2-18 were analyzed. Age had a significant effect on peak frequency, entropy and connectivity. Female sex was associated with significantly higher probability of positive responsiveness to photic stimulation (OR 4.28, CI [1.65, 11.73], p = 0.0036). Entropy decreases significantly during GSW (D = -0.29, CI [-0.31, -0.27], p ≪ 0.0001) and connectivity significantly increases (D = 0.39, CI [0.36, 0.40], p ≪ 0.0001). Within patient spike-voltage maps exhibit remarkable consistency between spikes. Spike-topographies cluster together to predict age, connectivity and entropy.

A quantitative characterization is possible and reveals significant relationships between age, sex and spike characteristics and multidimensional EEG features.

Quantitative GSW characterization can capture aspects from traditional qualitative GSW analysis while being unaffected by intra- and interrater variation and this may be useful for multidimensional predictors of patient outcomes in GGE in the future.