Shunsuke Nakae

Abstract The lateralized efficacy of vagus nerve stimulation (VNS) remains insufficiently explored. We report a case of drug-resistant epilepsy with bilateral frontal lobe seizure onset, treated with left cervical VNS. Preoperative video- electroencephalogram revealed predominant interictal discharges in the right hemisphere and frequent seizures from both hemispheres. Following VNS, overall seizure frequency decreased. Notably, stereo-electroencephalography performed 15 months postoperatively showed a marked reduction in right-sided seizures, while left-sided seizures remained frequent. This case highlights the potential lateralized effect of VNS in a single patient with bilateral frontal lobe epilepsy, suggesting that VNS may preferentially suppress seizures originating from the right hemisphere.

Posterior Quadrant Disconnection is a surgical technique designed to suppress seizure propagation while preserving motor and sensory functions in patients with drug-resistant epilepsy. Although seizure outcomes following this procedure have been reported, detailed evaluations of its impact on higher cognitive functions remain limited. This study aimed to assess the long-term seizure and cognitive outcomes following PQD in the non-dominant hemisphere, thereby evaluating the efficacy and safety of the procedure. In this case, the patient with drug-resistant epilepsy underwent preoperative evaluation using stereo electroencephalography (SEEG) to identify seizure onset zones and functional mapping related to visuospatial cognition. Following this assessment, PQD was performed. Postoperative outcomes were monitored over a 2-years period, focusing on seizure control and higher cognitive function. The patient achieved Engel class I status postoperatively, indicating complete seizure cessation. While transient hemispatial neglect was observed immediately after surgery, gradual improvement was noted over time. Furthermore, visual memory and cognitive functions showed a tendency to improve, and there were no significant declines in facial recognition or scene recognition abilities. These findings suggest that PQD can effectively improve seizure outcomes while minimizing long-term impacts on cognitive functions. This case highlights the potential of PQD to offer substantial seizure control with limited permanent effects on higher cognitive functions. By providing valuable insights into the safety and efficacy of PQD in the non-dominant hemisphere, this study underscores its viability as a treatment option for selected cases of drug-resistant epilepsy.

Karnofsky Performance Status (KPS) is a widely used scale to assess performance status. KPS ≥ 50% implies that patients can live at home. Therefore, maintaining KPS ≥ 50% is important to improve the quality of life of patients with glioblastoma, whose median survival is less than 2 years. This study aimed to identify the factors associated with survival time with maintenance of KPS ≥ 50% (survival with KPS ≥ 50%) in patients with glioblastoma, IDH-wildtype. Ninety-eight patients with glioblastomas, IDH-wildtype, who were treated with concomitant radiotherapy (RT) and temozolomide (TMZ) followed by maintenance TMZ therapy, and whose KPS at the start of RT was ≥ 50%, were included. The median survival with KPS ≥ 50% was 13.3 months. In univariate analysis, preoperative KPS (≥ 80%), KPS at the start of RT (≥ 80%), residual tumor size (< 2 cm3), methylated MGMT promotor, and implantation of BCNU wafer were associated with survival with KPS ≥ 50%. In multivariate analysis, KPS at the start of RT (≥ 80%), methylated MGMT promotor, and residual tumor size (< 2 cm3) were significantly associated with increased survival with KPS ≥ 50%. A strategy of maximum possible tumor resection without compromising KPS is desirable to prolong the survival time with KPS ≥ 50%.