EEG-based connectivity in patients with partial seizures with and without generalization

Background and purpose: A masodlagos generalizacio idegelettani alapjainak vizsgalata parcialis rohamokban. Methods: Inter-ictal, resting-state EEG functional connectivity (EEGfC) was evaluated and compared: patients with exclusively simple partial seizures (sp group) were compared to patients with simple partial and secondary generalized seizures (spsg group); patients with exclusively complex partial seizures (cp group) were compared to patients with cp and secondary generalized seizures (cpsg group); the collapsed sp+cp group (spcp) was compared to those who had exclusively secondary generalized seizures (sg group). EEGfC was computed from 21-channel waking EEG. 3 minutes of waking EEG background activity was analyzed by the LORETA Source Correlation (LSC) software. Current source density time series were computed for 23 pre-defined cortical regions (ROI) in each hemisphere, for the 1-25 Hz very narrow bands (1 Hz bandwidth). Thereafter Pearson correlation coefficients were calculated between all pairs of ROI time series in the same hemisphere. Z-scored correlation coefficients were compared at the group level (t-tests and correction for multiple comparisons by local false discovery rate, FDR). Results: Nagyobb EEGfC-ertekekből szarmazo tulkapcsoltsag jelentkezett specifikus frekvenciakon (spsg > sg; cpsg > cp) es szamos frekvencian (sg > spcp). Az eredmenyek a motoros es tobb, nem motoros kergi terulet kozti tulkapcsoltsagot tukrozik a betegekben, akiknek masodlagosan generalizalodo rohamai vannak. Tulkapcsoltsag igazolodott a medialis parietooccipitalis regiok es a feltekek lateralis reszei kozott is. Conclusion: Az interictalis allapotban mert halozati tulkapcsoltsag osszefugg a masodlagos generalizaciora valo hajlammal.