Predicting isocitrate dehydrogenase (IDH) mutations in gliomas using magnetic resonance imaging (MRI) is clinically important for treatment planning. This study compared two artificial intelligence (AI) models, GliomaDepth-IDH (ResNet34-based) and GliomaVista-IDH (Vision Transformer-based), with 18 physicians (eight neuroradiologists, five neurosurgeons, and five neurosurgery residents) in predicting IDH mutation status. On the Brain Tumor Segmentation Challenge dataset, the GliomaVista-IDH AI model achieved an area under the curve (AUC) value of 0.97, significantly outperforming all physician groups. However, external validation on a Japanese cohort revealed performance degradation: GliomaDepth-IDH declined to an AUC of 0.75 and GliomaVista-IDH to 0.82, with GliomaVista-IDH showing significant calibration issues (Brier score = 0.32). High-performing physicians achieved comparable results (AUC = 0.88) with superior calibration (Brier score = 0.19). Inter-rater reliability analysis revealed substantial variability across physician groups. These findings suggest that AI models can assist many physicians, while experienced practitioners remain competitive with better-calibrated predictions in challenging domains.

OBJECTIVE:In intracranial electrode implantation for drug-resistant epilepsy (DRE), stereoelectroencephalography (SEEG) has increasingly been adopted as a less invasive alternative to subdural grid (SDG) implantation; however, its impact not only on surgical safety outcomes but also on the actual postoperative recovery course remains insufficiently studied. This study compared postoperative recovery indicators between SDG and SEEG. METHODS:We retrospectively analyzed consecutive patients who underwent SDG or SEEG for DRE. Nine postoperative recovery outcomes were compared by univariable analysis: operation time, blood loss, time to adequate oral intake, number of analgesic administrations, number of antiemetic administrations, time to urinary catheter removal, time to body temperature normalization, time to white blood cell count normalization, and time to C-reactive protein normalization. In addition, exploratory multivariable regression analyses adjusted for age, sex, and year of procedure were performed. RESULTS:Participants comprised 47 patients (SDG, n = 23; SEEG, n = 24). In the univariable analysis, the SEEG group showed lower blood loss, earlier resumption of oral intake, fewer antiemetic administrations, shorter time to urinary catheter removal, and shorter time to WBC normalization. In the exploratory multivariable regression analyses, SEEG was significantly associated with reduced blood loss (p = 0.0022), shorter time to adequate oral intake (p = 0.0024), and fewer antiemetic administrations (p = 0.0134), and these associations remained significant after false discovery rate correction. CONCLUSIONS:Compared with SDG, SEEG was associated with reduced blood loss, earlier resumption of oral intake, and fewer antiemetic administrations. These findings suggest that SEEG may offer early postoperative recovery after intracranial electrode implantation.

PURPOSE:To elucidate associations between age at onset of epileptic spasms (ES) and clinical characteristics and outcomes. METHODS:We retrospectively included 277 patients diagnosed with ES at a single institution and categorized them into three groups based on age at ES onset: Group I (GI; <1 year), Group II (GII; 1-2 years), and Group III (GIII; >2 years). Etiology, seizure types, electroencephalography patterns, medical therapy, surgery, and seizure and cognitive outcomes were compared among groups. RESULTS:GI, GII, and GIII comprised 164 (59%), 53 (19%), and 60 (22%) patients, respectively. Structural etiology was most frequent in GI (51%) and less common in GIII (28%; p=0.010), whereas infectious etiology was least common in GI (4%; p<0.001). ES-free rates after medical therapy were higher in GI (42%) and GII (34%) than in GIII (12%) (p<0.001). Disconnection surgery achieved ES-free status in 21/29 (72%; odds ratio 3.88 [95% CI 1.60-9.41]) patients. Initial corpus callosotomy achieved ES-free status in 14/80 (18%). Absence of interictal multifocal/generalized spike-and-waves (MF/GSW-) and ES alone were significantly associated with ES-free status in GI and in all cohort. ES-free status was associated with better cognitive outcomes in GI and GIII. CONCLUSIONS:Age at ES onset was associated with etiology, electroclinical features, and treatment response. MF/GSW- and ES alone were associated with a higher likelihood of ES-free status. Disconnection surgery was associated with favorable ES outcomes in selected patients with structural etiologies.

Background: Awake craniotomy (AWC) is preferred when surgical procedures are performed near eloquent areas of the brain, commonly in the surgical treatment of gliomas and occasionally in epilepsy surgery. AWC is reported to offer better surgical outcomes with low complication rates in both entities. However, despite some similarities, differences in aspects of AWC between these two entities have not been comprehensively described in the literature. Methods: We searched the PubMed and Scopus database up to March 2024. Abstracts were screened and studies meeting the eligibility criteria were selected for detailed exploration. Results: The first search yielded 13 studies. However, thorough assessment identified only one study as potentially addressing our primary question of interest. The second search yielded 309 eligible studies, of which only four studies were deemed suitable for inclusion in the final review. However, thorough review revealed that none of the last four candidates met the criteria for inclusion in the review. Conclusions: This likely indicates that the differences regarding AWC between epilepsy surgery and glioma surgery are not well established among neurosurgeons. This scoping review presents a discussion of similar and different aspects that might influence the consideration of AWC. Both entities share similarities including defining a “safe entry” and “boundary” for resective surgery. However, these entities differ in terms of patient age, neuroplasticity target of surgery, extent of resection, number of chances to perform surgery, purpose of surgery, possibility of increased intracranial pressure and role of AWC. Neurosurgeons should be aware of similarities and differences in the ap-plication of AWC between glioma and epilepsy surgeries.

BACKGROUND:Acute disconnection syndromes frequently occur after corpus callosotomy (CC), with poor oral intake being among the symptoms. Most patients achieve normal oral intake by 2 weeks postoperatively. However, in some cases, feeding and swallowing functions fail to recover, and risk factors for delayed improvement in oral intake remain unclear. This study aimed to investigate the frequency of delayed improvement in oral intake at 2 weeks after CC, to descriptively examine feeding and swallowing function outcomes at 6 months postoperatively, and to identify associated risk factors. METHODS:A total of 76 CC procedures performed for refractory epilepsy between January 2015 and September 2023 were evaluated. Improvement in oral intake was classified as early (return to the usual form and quantity by postoperative week 2) or delayed (no improvement by week 2). Associations between clinical characteristics and delayed improvement in oral intake were analyzed. RESULTS:Of the 76 procedures, 13 (17%) were classified into the delayed improvement group, and oral intake failed to return to the usual form and quantity for more than 6 months in 3 procedures, all of which required gastrostomy. In multivariate analysis, preoperative oral intake not being age-appropriate and older age at CC were independent risk factors. CONCLUSIONS:Preoperative oral intake not being age-appropriate and older age at surgery are risk factors for delayed improvement in oral intake after CC. In patients with these risk factors, the possibility of delayed recovery should be considered and explained before surgery.

Background: Interhemispheric coherence, a coherence value between symmetrically opposite electroencephalography (EEG) electrodes, can be considered as a representation of connectivity through commissural fibers. In general, these commissural fibers are the major pathway of communication between hemispheres. However, in patients with drug-resistant generalized epilepsy (GE), these fibers also play an important role in propagating seizure activities to the contralateral hemisphere. The differences in interhemispheric coherence between epilepsy patients and patients without epilepsy (non-E) remain poorly understood. This study compared interhemispheric coherence values between these groups and discussed the potential usage of coherence analysis in the field of epilepsy. Methods: We retrospectively collected EEG data from patients with severe non-lesional GE over 20 years old who underwent corpus callosotomy. To compare interhemispheric coherence, EEG data from 10 non-E patients were prepared. In each patient, EEG data during non-rapid eye movement (NREM) sleep were collected. Interhemispheric coherence in eight pairs of electrodes in five frequency bands was calculated. Interhemispheric coherence values were compared between GE and non-E groups. Results: In each frequency band and electrode pair, interhemispheric coherence values of P3-P4 in delta, C3-C4 in theta, C3-C4 in alpha, F3-F4 and C3-C4 in beta, and C3-C4 and P3-P4 in gamma frequency band were significantly lower for GE than for non-E. The overall interhemispheric coherence value was significantly lower for GE than for non-E. Conclusions: Interhemispheric coherence values were lower for severe GE than for non-E in adults during NREM sleep.

Background Approximately 20 % of patients with Moyamoya disease develop drug-resistant epilepsy; however, the unusual hemodynamics following revascularization surgery increase the complexity of surgical interventions. Case We report a case of a 9-year-old girl with Moyamoya disease who underwent revascularization surgery at the age of 2 and subsequently developed drug-resistant epilepsy characterized by focal-to-atonic seizures and startle seizures that resulted in traumatic injury. After thorough preoperative evaluations of both intracranial and extracranial hemodynamics, a safe craniotomy entry site was identified in the high frontal region. Corpus callosotomy was achieved via a small craniotomy with neuroendoscopic assistance. Postoperatively, the frequency of startle seizures decreased to levels that no longer caused trauma, and the focal-to-atonic seizures were reduced by more than 50 %. Conclusion Corpus callosotomy via a small craniotomy may be an effective treatment option for drug-resistant epilepsy associated with Moyamoya disease.

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.