Long Term Outcome and Intraoperative Ecog Findings of Hippocampal Transection for Refractory Mesial Temporal Lobe Epilepsy
Abstract number :
2.281
Submission category :
9. Surgery / 9A. Adult
Year :
2022
Submission ID :
2204016
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:23 AM
Authors :
Tomohiro Yamazoe, MD, PhD – Seirei Hamamatsu General Hospital; Hiroshi Kawaji, MD, PhD – Seirei Hamamatsu General Hospital; Ayataka Fujimoto, MD, PhD – Seirei Hamamatsu General Hospital; Takamichi Yamamoto, MD, MSc – Seirei Hamamatsu General Hospital
Rationale: Hippocampal transection (HT) is one of the surgical strategies for refractory temporal lobe epilepsy to avoid decline in memory function, especially indicated for the language-dominant hemisphere. A relationship between intraoperative ECoG findings and the surgical outcome of HT was not yet reported. The long-term seizure outcomes for HT monitored with intraoperative ECoG recordings were fully examined.
Methods: Fifteen adult patients who underwent HT from December 2006 through June 2016 in our hospital were assessed from the medical records. The intraoperative ECoG were recorded under anesthesia using 2.5% sevoflurane after craniotomy. According to these findings, our surgical strategies could be modified intraoperatively in order to suppress epileptic activities of the hippocampus or the surrounding structures. The mean post-operative follow-up period was 7.3 years.
Results: Surgical outcomes demonstrated that 5 out of 15 patients achieved Engel class I-a, 2 class I-b, the other 2 class II-b, the other 5 class III-a, and one patient obtained class IV-b. After assessment of intraoperative ECoG recordings, 7 patients had additional surgical procedures, two cases; adding HT after resection of cavernous hemangioma and enlarged amygdala respectively, two cases; adding disconnection near the hippocampus, two cases; adding disconnection of the temporal tip, one case; adding more HTs. In the findings of intraoperative ECoG, residual synchronized spikes in more than two electrodes on the hippocampus were observed in six patients with class III-a or IV-b.
Conclusions: Seven out of 15 patients who underwent HT with intraoperative assessment with ECoG achieved seizure freedom (class I) and the other 7 showed improvement in seizures frequency. The residual synchronized spikes in hippocampus were correlated with worse seizure outcomes by HT. HT with assessment of the intraoperative ECoG is useful strategy for refractory temporal lobe epilepsy and intraoperative ECoG findings may predict the long-term seizure outcomes after HT.
Funding: None
Surgery