Authors :
Presenting Author: Takumi Mitsuhashi, MD,PhD – Juntendo University
Yasushi Iimura, MD,PhD – Juntendo University
Hiroharu Suzuki, MD,PhD – Juntendo University
Tetsuya Ueda, MD, PhD – Juntendo University
Kazuki Nishioka, MD – Juntendo University
Kazuki Nomura, MD – Juntendo University
Madoka Nakajima, MD, PhD – Juntendo Univerisity
Hidenori Sugano, MD,PhD – Juntendo University
Akihide Kondo, MD,PhD – Juntendo University
Rationale:
To evaluate the feasibility of the dynamic tractography-based spike source localization (DT-based SSL) method using SEEG.Methods:
The present study investigated 900 spike events recorded in 6 patients with drug-resistant focal epilepsy who underwent extraoperative stereoelectroencephalography and resective surgery. In each patient, we estimated the sources of 100 spike discharges using the latencies of 20-70Hz amplitude augmentation at given electrode sites and diffusion-weighted imaging-based streamline length measures. We determined whether the spatial relationship between the estimated spike sources and resection was associated with postoperative seizure outcomes. We visualized the spatiotemporal change of spike-related fiber activation sites by estimating the propagation velocity using the streamline length and spike latency measures.
Results:
The spike propagation velocity from the source was 0.61-1.49 mm/ms on average. The estimated spike sources with International League Against Epilepsy (ILAE) class 1 outcome were mainly in the resected area. A patient with bilateral temporal lobe epilepsy presented two patterns of spike discharges, one with spike sources in the left medial temporal lobe and the other in the right medial temporal lobe. Left anterior temporal lobectomy was performed, resulting in ILAE class 4 outcome. Another patient showed two patterns of spike discharges, one with the spike sources in the temporal lobe and the other in the frontal lobe. Anterior temporal lobectomy resulted in ILAE class 5 and frontal disconnection resulted in ILAE class 4. The dynamic tractography successfully visualized spike propagations from the estimated spike sources to a given electrode site.
Conclusions:
DT-based SSL methods can provide spike sources using SEEG. In cases with multiple patterns of spike discharges, it is necessary to consider which spike sources correspond to the seizure onset zone.
Funding:
JSPS KAKENHI Grant Number 22K15468