OC04 : High frequency oscillations associate with IL1Β/HMGB1/TLR4 pathway activity in low-grade epilepsy associated tumors. (March 2022)

• Record Type: Journal Article
• Authors: Sun, D.; Van Klink, N.; Bongaarts, A.; Zweiphenning, W.; Van 't Klooster, M.; Gebbink, T.; Snijders, T.; Robe, P.; Aronica, E.; Zijlmans, M.
• Is Part Of: Clinical neurophysiology. Volume 135(2022)
• Page Start: e15
• Page End: e16
• Publication Date: 2022-03
• Subjects: Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2021.11.056
• Languages: English
• ISSNs: 1388-2457

Abstract

Abstract : High frequency oscillations (HFOs) in intraoperative electrocorticography are thought to be generated by hyperexcitable neurons. Inflammation may promote neuronal hyperexcitability. We investigated the relation between HFOs and inflammation in tumor-related epilepsy. Methods: We identified HFOs (ripples 80-250Hz, fast ripples 250-500Hz) in the intraoperative electrocorticography of 32 patients with low-grade tumors. Localization of recorded HFOs was classified based on MRI reconstructions: in the tumor, in the resected non-tumorous area and outside the resected area. We tested if the following inflammatory markers in the tumor or the peritumoral tissue were related to HFOs: activated microglia, CD3-positive T-cells, interleukin 1-beta (IL1β), toll-like receptor 4 (TLR4) and high mobility group box 1 protein (HMGB1). Results : Tumors that generated ripples had more CD3-positive T-cells infiltrating the tumor tissue than tumors without ripples. Increased ripple rate outside the resected area is correlated with increased immunoreactivity of IL1β, TLR4 and HMGB1 in the peritumoral tissue. Conclusions: Ripple rate in intraoperative electrocorticography is associated with the number of CD3-positive T-cells in the tumor and IL1β/HMGB1/TLR4 pathway activity in the peritumoral tissue. Our findings support that ripple generation and spread may be associated with synchronized fast firing of hyperexcitable neurons caused by neuroinflammation. This pilot study provides arguments for further investigations in HFOs and inflammation.