Abstracts

Rationale: Recent studies suggest that glia influence epileptogenesis. Studies of specimens from epilepsy surgery reported increased oligodendroglial-like cells (OLC) in the white matter. Oligodendrogliosis is defined as clusters or linear arrays of OLC (Olig2-reactive). We examined the OLC population in the resected specimens from children with intractable focal epilepsy.Methods: We retrospectively collected 30cases (18 female) who underwent intracranial EEG. The neuropathological findings were correlated with the clinical data. The neuropathology examination utilized H&E/LFB and immunohistochemical staining for NeuN, GFAP and Olig2. OLC were counted in three sites: a) gray matter, b) junction of gray/white matter, and c) white matter. We also examined the correlation between the density of OLC among the three sites and the clinical features (seizure type, diagnosis).Results: Seizure types consisted of partial seizures in 20patients, epileptic spasms (ES) in 10. We found focal cortical dysplasia in 16/30(53%) cases and oligodendrogliosis in 16/30(53%) cases. OLC were observed in all 30cases. The density of OLC at c) significantly increased than other groups (p<0.01). 10patients with ES showed significantly increased the density of OLC at b) and c) than 20patients without ES (p<0.05). The density of OLC at b) and c) significantly increased in 16 oligodendrogliosis than others (p<0.05).Conclusions: Increased OLCs at the junction and white matter in patients with epileptic spasms may facilitate wide spread epileptic networks to provoke spasms.