Abstracts

Rationale: Resective epilepsy surgery is an established treatment for drug-resistant focal epilepsy, but is associated with postoperative neurological deficits. Cortical resection may cause unexpected wedge-shaped white matter infarction extending from the bed of resection cavity towards the ventricle on the post-surgical MRI. The infarction extending to the corticospinal tract and language fibers can result in irreversible neurological deficits. Predicting the occurrence of these infarctions is challenging. Recent studies suggest that stereotactic radiofrequency thermocoagulation (RFTC) is a promising alternative treatment for insular epilepsy, offering a relatively low risk of heat injury to vascular structures. Consequently, RFTC may help avoid the unexpected complications associated with white matter infarctions. This study was conducted to retrospectively evaluate unexpected symptomatic complications due to white matter infarction associated with cortical resection in epilepsy surgery and to confirm the efficacy of RFTC.


Methods: This was a case-control study targeting patients who underwent cortical resection or RFTC between January 2018 and March 2023. The presence of white matter infarction was assessed using diffusion-weighted MRI taken 7-10 days postoperatively. Symptomatic complications due to white matter infarction were defined as symptoms unexplained by the functional localization of the resected or coagulated cortex, persisting for more than one year. Preoperative clinical characteristics were compared between the two groups using the Mann-Whitney U test. Postoperative seizure outcomes at one year were classified using the Engel classification and compared using the chi-square test. The incidence of white matter infarction and unexpected symptomatic complications was compared using Fisher's exact test.


Results: The study included 47 cases of cortical resection and 7 cases of RFTC. The median age at surgery was 11 years in the cortical resection group and 6 years in the RFTC group. There were no statistically significant differences in preoperative clinical characteristics between the two groups. Additionally, there was no significant difference in postoperative seizure outcomes with Engel class 1 outcomes between the groups (p=0.98). White matter infarction in the deep resection cavity was observed in 22/47 cases (46.8%) in the cortical resection group, significantly higher than in the RFTC group (p=0.019). Unexpected neurological deficits due to white matter infarction were observed in 4/47 (8.5%) cases in the cortical resection group, but not in the RFTC group (p=0.56).


Conclusions: RFTC for drug-resistant focal epilepsy offers equivalent seizure outcomes to cortical resection while potentially avoiding unexpected neurological complications associated with white matter infarction.


Funding: This study did not receive any funding.