Abstracts

Rationale: Generalized Spike and Wave Discharge (GSWD) is an important characteristic of juvenile myoclonic epilepsy (JME) which is a kind of idiopathic generalized epilepsy. Hence, investigating GSWD may lead to understand underlying pathophysiology of JME. To study characteristics of neuronal network during GSWD, graph theoretical analysis of connectivity network was conducted in present study. Methods: 64-channel EEG data were acquired from 3 patients with JME. Representative epochs during spike free baseline period and GSWD of 1 s were selected. The coherence in each pairwise combination of two electrodes was calculated for each frequency band (i.e., delta, theta, alpha, beta, gamma, and ripple). Graphs were constructed from this coherence matrix by applying upper 95% threshold, and characterized by a characteristics path length and a clustering coefficient. The graph measures were compared between baseline and GSWD. Results: During GSWD, coherence was increased over all frequency bands, and increasing in gamma and ripple band was noticeable, especially. Furthermore, spatial characteristic of connectivity shows that bilateral frontal region was highly involved. The clustering coefficient was increased during GSWD in the beta, gamma, and ripple bands, whereas the shortest path length showed only slight changes through all frequency bands. Conclusions: Our results showed the changes of neural synchronization during GSWD were more related to high frequency oscillations (HFO) than low band, which suggests HFO plays an important role for GSWD. The clustering coefficient is a measure of the local interconnectedness of the graph. Thus, increasing clustering coefficient of neural network in high frequency band during GSWD may imply that specific regions are highly involved in onset and propagation of GSWD, which is consistent with previous studies.