Victoria San Antonio-Arce

Objective: Chapeau de gendarme (CdG) is a subtle but clinically relevant semiology that has been scarcely studied in children. Previous studies have primarily focused on its localizing value in small, surgical cohorts. This study aimed to systematically characterize frequency and clinical features of CdG across the pediatric age spectrum. Methods: We retrospectively analyzed video‐electroencephalography (EEG) monitoring of 264 children with epilepsy (0–17 years). Up to 10 seizures per type were reviewed per patient. CdG was defined as a symmetrical downward contraction of both mouth corners and chin contraction lasting ≥5 s. CdG characteristics, co‐occurring semiologies, and EEG patterns were assessed and compared to the cohort without CdG. Results: CdG was identified in 28 of 264 patients (10.6%), corresponding to 73 seizures. The median age at first observed CdG was 12.3 years (range 1.3–16.8), with a trend toward increasing frequency in older children. All but one case occurred in focal epilepsies, which were significantly more frequent in the CdG cohort than in those without CdG ( p = .009). CdG appeared early in the seizure course (≤5 s in 61.6%) and more often during sleep ( p < .001). Hyperkinetic behavior occurred significantly more often in CdG seizures ( p < .001). Progression to bilateral tonic–clonic seizures was recorded in 20.5% of CdG seizures (17.9% of patients with CdG) and occurred more frequently in the CdG cohort than in patients without CdG ( p < .001). The first ictal scalp EEG pattern most frequently involved the frontal lobe (57.7%). Significance: CdG occurred in a notable proportion of pediatric patients across the entire age range, with a descriptive tendency toward higher occurrence in older children. These findings provide an essential foundation for future investigations exploring developmental and network mechanisms underlying this semiology.

Objective: Pathogenic variants in COL4A1/2 compromise vascular basement membrane integrity, causing intrauterine hemorrhage and infarction leading to extensive structural brain lesions. Vascular disruptions during critical windows of neuronal migration can result in malformations of cortical development (MCD), which may drive epileptogenicity. While surgery is established for drug‐resistant focal epilepsy, COL4A1/2 patients with widespread or bilateral MRI abnormalities are frequently deemed ineligible. In selected patients, this necessitates a refined surgical rationale, shifting from strictly curative goals to “non‐curative” strategies focused on seizure mitigation and functional preservation. Methods: This retrospective multicenter study analyzed six previously unpublished patients (3 COL4A1 , 3 COL4A2 ) from three German epilepsy centers. We evaluated presurgical diagnostics (MRI, PET), surgical techniques, histopathology, and outcomes. Results were contextualized with a review of 11 previously published cases. Results: All patients experienced daily seizures and developmental delay prior surgery. MRI revealed bilateral abnormalities in 4/6 patients (e.g., ventriculomegaly, white matter lesions). Surgical procedures included hemispherotomy ( n = 4) and posterior quadrant disconnection/resection ( n = 2). Mean follow‐up was 5 years 11 months (range 2 years 10 months–8 years 9 months). Seizure freedom (ILAE 1) was achieved in 2/6 patients (33%), both of whom had unilateral lesions. While patients with bilateral lesions remained at ILAE 4, 83% showed postoperative developmental improvement. Histopathology confirmed cortical malformations in three patients (FCD IIId, mMCD II, GW‐matter blurring), supporting the hypothesis that secondary cortical malformations, rather than macroscopic lesions, drive epileptogenicity. No surgical or neurovascular complications were observed. Significance: Epilepsy surgery is a feasible and safe treatment option for COL4A1/2 ‐associated epilepsy. While curative in patients with unilateral lesions, bilateral cases can benefit from a “non‐curative” approach focused on seizure mitigation and neurodevelopmental protection. Multimodal imaging, specifically FDG‐PET, can be helpful in identifying highly epileptogenic cortical areas within widespread structural damage and serve as a basis for surgical planning.

Objective: Invasive presurgical evaluation plays a key role in pediatric epilepsy surgery, particularly in magnetic resonance imaging (MRI)‐negative cases, by guiding resective, disconnective, or ablative procedures. This International League Against Epilepsy (ILAE) Pediatric Epilepsy Surgery Taskforce study provides an updated global overview of current invasive evaluation practices. Methods: Group‐level data were collected from 61 epilepsy surgery programs (49 pediatric‐only) in 29 countries across six continents. Included were children and adolescents who underwent presurgical evaluation and epilepsy surgery in 2023. The study was designed to enable comparison with the similar ILAE survey conducted in 2004. Results: A total of 2427 patients were included. Invasive evaluations were performed in 21.1% of cases, most frequently in North America (33.7%, higher than Europe: 18.0%, p = .003). Among invasive cases, 32.3% had no detectable MRI abnormalities. The main indication for invasive evaluation was seizure onset localization (88.1%), followed by motor or sensory mapping (17.2%) and language mapping (14.2%). Stereoelectroencephalography (SEEG) was the predominant technique (19.8% overall, 93.6% of invasive cases), more common in North America (30.0%, p = .021) and less common in South America (7.4%, p < .001). Subdural electrodes were used in only 3.2% of invasive cases, and combined depth and subdural approaches in 3.2%. SEEG‐guided radiofrequency thermocoagulation (RF‐TC) was performed in 40.9% of SEEG cases, most commonly in Asia (63.8%). In 16.2% of invasive evaluations, patients did not proceed to resection, disconnection, or ablation, with the highest rate in Europe (28.5%). Significance: This global survey provides the first broad overview of invasive evaluation practices in pediatric epilepsy surgery across participating centers worldwide. It highlights the widespread adoption of SEEG, declining use of subdural electrodes, and increasing application of SEEG‐guided RF‐TC. The high proportion of MRI‐negative cases and the considerable proportion of patients not proceeding to resection, disconnection, or ablation underscore the complexity of contemporary surgical candidates and the need for further refinement of selection strategies.

Objective: Detection of focal cortical dysplasia (FCD) remains a major challenge in presurgical epilepsy diagnostics. Magnetic resonance imaging (MRI) morphometry increasingly improves lesion detection and postsurgical outcomes. The volume‐based Morphometric Analysis Program, version 2018 (MAP18) with integrated artificial neural network and surface‐based Multi‐centre Epilepsy Lesion Detection (MELD; MELD Graph) MRI morphometry algorithms have demonstrated diagnostic utility, but their performance has not been directly compared within a single cohort of surgically treated patients with histopathologically confirmed FCD. Methods: We retrospectively analyzed 3‐T MRIs of 32 FCD patients who underwent epilepsy surgery. MAP18 was applied to MP2RAGE (magnetization‐prepared 2 rapid gradient echo) sequences and MELD to T1MPRAGE (magnetization‐prepared rapid gradient echo) and three‐dimensional FLAIR (fluid‐attenuated inversion recovery) sequences. Binary lesion masks served as ground truth for evaluating detection accuracy, precision, and recall at cluster and voxel levels. Clinical correlation analysis assessed spatial concordance with seizure onset zone (SOZ) and irritative zone (IZ) from video‐electroencephalography (EEG) and postoperative outcome. Results: The cohort included 34 histopathologically proven FCD lesions (91.2% FCD II, 5.8% mild malformation of cortical development, 2.9% unspecified). MELD identified 32 of 34 lesions (94.1%), and MAP18 identified 33 of 34 lesions (97.1%), with concordance in 32 of 34 lesions (94.1%). At the cluster level, MELD showed significantly higher precision ( p < .001) and fewer false positive clusters per patient (median 0 vs. 3, p < .001). Voxelwise analysis revealed that MELD demonstrated significantly higher precision than MAP18 (.42 vs. .13, p < .0001) and recall (.44 vs. .23, p < .01). Lobar concordance with SOZ reached 90.6% and with IZ reached 87.5%. Among invasive EEG patients, overlap with SOZ and IZ was 100%. Seizure freedom (Engel I) was achieved in 87.5% of patients. Significance: Under standardized high‐resolution 3‐T MRI, both algorithms achieved high detection rates with strong concordance. Combined application may enhance presurgical lesion detection, with results limited to surgically treated patients.

Objective: To assess informed acceptance and perceptions of the 2025 update of the International League Against Epilepsy (ILAE) seizure classification—after participants had received a focused educational introduction to the updated classification. Methods: We analyzed anonymized live poll responses from two educational webinars dedicated to the updated seizure classification: an EpiCARE webinar held on March 26, 2026, and an ILAE e‐Forum held on April 15, 2026. At the start of the webinars, participants reported their professional background and prior familiarity with the updated classification. Each webinar then included a 20‐min teaching session, after which participants answered a poll question on their opinion of the updated classification. In the EpiCARE webinar, participants additionally classified 16 representative video‐EEG cases using the updated classification. For the case exercise, we summarized question‐level accuracy, the most frequent incorrect answer, the micro‐average accuracy (total number of correct responses across all submitted answers divided by the total number of submitted answers), and the macro‐average accuracy (mean of the 16 individual case accuracies). Results: A total of 323 participants actively engaged in the two webinars (185 in the EpiCARE webinar and 138 in the ILAE e‐Forum). Most respondents were specialist neurologists or pediatric neurologists/pediatricians. Before the teaching session, most respondents had heard about the updated classification but had not read the full position paper and practical guide. The main post‐teaching poll was completed by 295 participants (91.3%). The vast majority of the respondents (242; 82%) rated the updated classification as feasible and useful, 17 (5.8%) as feasible but not useful, and 2 (0.7%) as not feasible, and 34 (11.5%) respondents stated they were unsure / had no opinion. In the case‐based exercise on applying the updated classification, the most frequently selected answer was correct in all 16 cases. The micro‐average accuracy was 74.3%, the macro‐average accuracy 74.5%, and the median question‐level accuracy 81.5% (range 30.4%–94.0%). Significance: When neurologists and other professionals were surveyed after structured teaching, acceptance of the 2025 ILAE seizure classification was strongly favorable. These findings suggest that education is likely to influence how the update is perceived and may help explain part of the skepticism reported in earlier surveys conducted without a standardized teaching intervention.

Objective: Focal cortical dysplasia ( FCD ) is a leading cause of drug‐resistant epilepsy and is associated with sleep‐related seizures, yet the underlying electrophysiological mechanisms during different brain states remain poorly understood. We investigated whether fast oscillations ( FOs ) within the seizure onset zone ( SOZ ) and irritative zone ( IZ ) change significantly during sleep compared with wake in FCD patients. We analyzed multiple frequency bands—beta (14–20 Hz), gamma (40–80 Hz), ripple (80–250 Hz), and broadband BGR (14–250 Hz) to provide comprehensive information about sleep‐related changes. We hypothesized that sleep‐related FO changes would be associated with sleep‐related epilepsy, frontal location, or FCD type II . Methods: We examined intracranial EEG ( iEEG ) recordings from 22 FCD patients undergoing presurgical evaluation between 2010 and 2023, with a mean age of 25.3 ± 12.8 years and a disease duration of 17.7 ± 12.3 years. Using semiautomated detection, we compared FO rates between wake and sleep epochs, focusing on contacts within IZ and SOZ . Distance‐based multivariate analysis of variance ( MANOVA ) was employed for patient‐level analysis, accounting for spatial organization and enabling multiband evaluation. Results: Analysis of 67 ± 28 bipolar iEEG contact pairs per patient revealed distinct sleep‐related patterns. In SOZ , gamma oscillations showed significant increases in 10/22 patients (45%), followed by BGR in 7/22 patients (32%). IZ exhibited stronger changes, with BGR and gamma showing significance in 13/22 patients each (59%) with high concordance. Gamma oscillation rates in SOZ increased in patients with confirmed sleep‐related epilepsy ( p < 0.05), while no associations were found with frontal location or FCD type II . Significance: Gamma oscillations showed robust sleep‐related increases in SOZ , while gamma and BGR frequencies demonstrated strong changes in IZ , often occurring simultaneously. These findings suggest gamma oscillations, complemented by BGR analysis, may qualify as markers for characterizing sleep‐related changes in FCD patients, potentially advancing understanding of mechanisms underlying sleep‐related seizures. Plain Language Summary: Focal cortical dysplasia (FCD) is a brain malformation that causes difficult‐to‐treat epilepsy, with patients experiencing seizures mainly during sleep. We studied electrical brain waves in 22 FCD patients using electrodes placed directly within or on the brain during pre‐surgery evaluation. We compared brain wave activity between wake and sleep, focusing on fast brain waves. We found that fast brain waves, especially gamma waves, increased significantly during sleep in brain areas where seizures start, particularly in patients whose seizures occur mainly during sleep. These findings potentially help us better understand why seizures happen more often during sleep in FCD patients.

Consensus‐based recommendations (CBRs) are essential for health care decision‐making when evidence is limited or conflicting. They can be developed using established methodologies such as the Delphi technique, the nominal group technique (NGT), and the RAND Corporation/University of California Los Angeles (UCLA) Appropriateness Method (RAM). This review explores the advantages and disadvantages of these methods and their applications in epilepsy. A narrative review using PubMed (November 22, 2017 to November 22, 2022) was undertaken examining publications describing Delphi, NGT, and RAM. The frequency of use of each method and their applications in epilepsy care were also reviewed (1966 to October 31, 2023). Sixteen articles were included describing the different consensus‐based methods. The advantages and disadvantages of each method varied widely. The Delphi technique, the most widely used method, emerged as adaptable for instances with limited evidence or impracticality of face‐to‐face interactions. Although NGT favors prompt consensus in single‐session formats, the RAM offers a balanced approach with its hybrid structure. We identified 64 epilepsy studies that used consensus methods, with 58 utilizing the most widely used technique, the Delphi. The Delphi guided consensus mostly for management including for individuals with rare conditions such as myoclonic–atonic seizures or in those with epilepsy and pregnancy. The NGT guided expert consensus on the use of cannabidiol for Dravet and Lennox–Gastaut syndromes and facilitated decision‐making among pharmacy students addressing ethical issues related to patients with epilepsy who drive. The RAM was applied in four studies for its combined individual and group evaluative approach. It was used to develop recommendations or imaging, create quality‐of‐care indicators for infantile spasms, and establish a web‐based tool for assessing surgical candidacy. Consensus methodologies are crucial to inform robust CBR for epilepsy management where clinical practice guidelines are not possible due to limited evidence. The best method depends on the study goal and available resources.

Objective: Hypothalamic hamartomas (HHs) lead to refractory epilepsy, and minimally invasive surgical approaches are standard of care for affected patients. Stereotactic radiofrequency thermocoagulation (SRT) is one of the treatment methods recognized to achieve seizure freedom. This study reports surgical outcome from a single center reporting an ablation technique using fewer trajectories than previously reported and assesses the effect of coagulated volume on long‐term seizure freedom. Methods: Retrospective analysis was made of all patients who underwent SRT at the University of Freiburg between 2016 and 2024 with a follow‐up of ≥12 months. Statistical analysis was made of outcome dependent on type of hamartoma, seizure type, coagulation volume (based on magnetic resonance imaging evaluation), and epilepsy duration. Results: Forty‐three patients received SRT; 35 (22 children) had >12 months of follow‐up, with a median of 38 months. Nine patients had two SRTs, and two patients had three SRTs. Twelve months after their last SRT, 60% of patients were seizure‐free, 88.6% were free of bilateral tonic–clonic seizures, and 77.1% were free of gelastic seizures (last follow‐up: 54.3% seizure‐free, 88.6% free of bilateral tonic–clonic seizures, 74.3% free of gelastic seizures). There was a significant reduction of antiseizure medication (ASM) postsurgically, with an average number of ASMs of two prior to surgery and one after surgery. After 12 months, 14.3% of patients experienced ongoing but mostly mild surgical complications, with hypothalamic dysfunction being the most common. Coagulation volumes were higher in larger HHs, but no correlation was observed between coagulated volume and seizure freedom or complication rates. Significance: SRT is a minimally invasive method to successfully treat refractory seizures in patients with HH. Disconnection seems to be more important for successful treatment than volume reduction. Even large HHs can be successfully treated with small coagulation volumes.