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Periventricular nodular heterotopia (PVNH) is a neuronal migration disorder often associated with drug‐resistant epilepsy. The epileptogenic zone network (EZN) in PVNH is generally large, contraindicating surgery. Stereoelectroencephalography (SEEG) can be proposed to map the EZN and perform radiofrequency thermocoagulation (THC) with an efficacy rate of approximately 65%. There are genetic forms of PVNH, particularly with mutations in the filamin A gene (FLNA). However, data on SEEG‐guided THC in these patients still have not been described. We report four patients with FLNA‐positive PVNH who underwent SEEG‐guided THC. All were women with several types of seizures and psychiatric comorbidities. EZN was extensive and often bilateral, including a part of the heterotopias. The outcomes of SEEG‐guided THC varied; two patients experienced significant seizure reduction and improvement in psychiatric symptoms (Engel class I–II), one showed partial improvement (Engel class III), and one had no significant benefit (Engel class IV). Psychiatric comorbidities, including posttraumatic stress disorder, depression, and anxiety, were present in all cases, with some patients showing symptom improvement alongside seizure reduction. Despite genetic origin, SEEG‐guided THC can be proposed in FLNA‐positive PVNH‐related epilepsy, although outcomes vary. The presence of FLNA mutations should not contraindicate surgical intervention but may influence the therapeutic response. Further research is needed to understand the impact of genetic variants on epilepsy outcome. [ABSTRACT FROM AUTHOR]

Objective: To assess seizure and developmental outcomes, their predictors, and complications in 160 children who, between 1998 and 2022, underwent surgery for lesional epilepsy with curative intent before the age of 3 years. To compare trends in epilepsy surgery in this age group before and after the year 2014. Methods: Retrospective multicenter study. Descriptive and univariate analyses, and multivariable models for all outcomes. Results: These 160 patients (76 F; 47.5%) underwent 169 surgeries (age at surgery 20.4 ± 9.4 months). At the last follow‐up (77 ± 57.4 months), 121 patients (75.6%) were in Engel class I, 106 (66.2%) of whom were in Engel class Ia. Antiseizure medications were stopped in 84 patients (52.5%). Complications requiring reoperations were observed in 16 patients (10%; 9.5% of surgeries) and unexpected permanent deficits in 12 (7.5%; 7.1% of surgeries). Postoperative cognitive functions remained unchanged in 56 patients (44.4%), improved in 51 (40.5%), and worsened in 19 (15.1%). Multivariable analyses showed that the probability of achieving Engel class Ia was lower when the duration of epilepsy was longer, patients underwent preoperative video‐EEG, and unexpected postoperative permanent deficits occurred. Cognitive improvement after surgery was associated with lower preoperative seizure frequency, better preoperative developmental level, and a longer postoperative follow‐up. FCDII and tumors were the histopathologies carrying a higher probability of achieving seizure freedom, while polymicrogyria was associated with a lower probability of cognitive improvement. The number of patients operated on after 2014 was higher than before (61.3% vs. 38.7%), with stable outcomes. Significance: Epilepsy surgery is effective and safe in infants and toddlers, although the complication rate is higher than seen in older patients. Shorter duration of epilepsy, lower seizure frequency, no need for video‐EEG, tumors, and some malformations of cortical development are robust predictors of seizure and cognitive outcome that may be exploited to increase earlier referral. Plain Language Summary: This study analyzed the results of epilepsy surgery in 160 children who had been operated on before the age of 3 years at four Italian centers between 1998 and 2022. At the last follow‐up (77 ± 57.4 months), 121 patients (75.6%) were free from disabling seizures, of which 106 (66.2%) were completely seizure‐free since surgery. Major surgical complications occurred in 28 patients (17.5%), which is higher than observed with epilepsy surgery in general, but similar to hemispheric/multilobar surgery. Postoperative cognitive function remained unchanged in 56 patients (44.4%), improved in 51 (40.5%), and worsened in 19 (15.1%). Epilepsy surgery is effective and safe in infants and toddlers. [ABSTRACT FROM AUTHOR]

Objective: Cortical intracerebral electrical stimulation is an important tool for language mapping in the presurgical work‐up of patients with drug‐resistant focal epilepsy. Language mapping with stereo–electroencephalography (EEG) is usually performed by high‐frequency stimulations (HFS: 50 Hz), whereas low‐frequency stimulations (LFS: 1 Hz) are usually considered useful for primary cortices mapping. Little is known in literature about "intermediate" frequencies (IFS: 6–15 Hz). Our objective is to explore the clinical usefulness of IFS in language mapping and identify factors, beyond the electrical parameters, that impact the mapping. Methods: We studied 23 patients submitted to stereo‐EEG for presurgical evaluation. Language mapping was performed in the anterior, posterior and/or basal language region of the dominant hemisphere for language. We included all contact positions within these regions stimulated by HFS (50 Hz, 5 s, 1–3 mA) and IFS (6‐15 Hz, 15 s, 5 mA). We compared the capability of both stimulation methods to induce a language deficit without afterdischarges (ADs), and we analyzed factors related to clinical examination, region, and stimulation technique by multivariate analysis. Results: A total of 211 stimulations (98 HFS, 113 IFS) in 70 cortical sites within the anterior (84 stimulations), posterior (137), and basal language region (60) were included. IFS induced more frequently language deficits not associated to AD compared to HFS (37.1% vs 25.7%, p =.0043), whereas HFS provoked more diffuse AD (34.7% vs 15.0%, p =.001). Investigating multiple language functions increased the probability of revealing a deficit (odds ratio [OR] 3.16, p =.0016), independently of the stimulation method. Significance: IFS are valuable for language mapping, thereby improving the probability of inducing a clinical deficit not accompanied by an AD. The completeness of the clinical examination independently affects the sensitivity of the mapping. IFS are a new tool with potential usefulness for the cortical mapping of other associative cortical regions. [ABSTRACT FROM AUTHOR]

The identification of the epileptogenic zone (EZ) boundaries is crucial for effective focal epilepsy surgery. We verify the value of a neurophysiological biomarker of focal ictogenesis, characterized by a low‐voltage fast‐activity ictal pattern (chirp) recorded with intracerebral electrodes during invasive presurgical monitoring (stereoelectroencephalography [SEEG]). The frequency content of SEEG signals was retrospectively analyzed with semiautomatic software in 176 consecutive patients with focal epilepsies that either were cryptogenic or presented with discordant anatomoelectroclinical findings. Fast activity seizure patterns with the spectrographic features of chirps were confirmed by computer‐assisted analysis in 95.4% of patients who presented with heterogeneous etiologies and diverse lobar location of the EZ. Statistical analysis demonstrated (1) correlation between seizure outcome and concordance of sublobar regions included in the EZ defined by visual analysis and chirp‐generating regions, (2) high concordance in contact‐by contact analysis of 68 patients with Engel class Ia outcome, and (3) that discordance between chirp location and the visually outlined EZ correlated with worse seizure outcome. Seizure outcome analysis confirms the fast activity chirp pattern is a reproducible biomarker of the EZ in a heterogeneous group of patients undergoing SEEG. [ABSTRACT FROM AUTHOR]