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Objective: Identification of eloquent cortices is a prerequisite for the surgical plan but may be challenging, in particular for language areas (LAs), considering the complexity of language function and organization. Electrical intracerebral stimulations (ES) during Stereo-electroencephalography are an essential tool in the localization of LAs and high frequency ES (HFS, 50 Hz) are current gold standard. Low frequencies (1 Hz) are not effective. We aim to investigate different ES frequencies for establishing their utility in localizing LAs., Methods: We implemented an observational and prospective study evaluating frequencies lower than 50 and higher than 1 Hz; indicated as "intermediate" frequencies (IFS) performed at 6, 9 and 12 Hz and lasting 15 seconds. We included ten patients and carried out a standardized protocol comparing IFS to HFS., Results: Eighty-six ES were carried out in LAs, positive for a language interference in 61.6% without noteworthy difference between IFS and HFS. Among these, 53.3% IFS vs 21.7% HFS yielded no after-discharge., Conclusions: IFS were similarly effective as HFS, with lower incidence of ADs. Their longer duration facilitated more accurate clinical testing., Significance: Our results are promising, suggesting that IFS can be useful in the study of LAs., (Copyright © 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Purpose: This study aimed to identify risk factors of postoperative seizure outcome in a consecutive cohort of patients operated on for TSC-related focal epilepsy, by evaluating several presurgical and surgical variables, including also MRI-visible brain abnormalities other than cortical tubers., Methods: This retrospective study included 51 patients surgically treated for drug-resistant focal epilepsy with a histological diagnosis of cortical tuber and followed for at least 12 months postoperatively. We investigated the association between several potentially explanatory variables and seizure outcome by univariate and multivariate analysis in the whole cohort and in the subgroups of patients with single and multiple tubers, respectively., Results: The median postoperative follow-up was 115 months (IQR 63-168) and 54.9% of patients were in Engel's class I at final control. In the whole cohort, variables independently associated with an unfavorable seizure outcome (Engel's classes II-IV) were: preoperative non-focal interictal EEG (RR 5, CI 2.46-6.39), presence of sub-ependymal nodules (SEN) (RR 3.53, CI 1.71-4.56) and seizure onset before the first year of age (RR 3.56, CI 0.91-6.89). Non-focal interictal EEG was independently associated with an unfavorable outcome also in the subgroup of patients with multiple tubers (RR 4.34, CI 2.23-5.37), while the presence of SEN (p=0.0221) and of extra-central nervous system lesions (p= 0.0152) predicted an unfavorable seizure outcome in patients with a single tuber., Conclusion: Surgery represents an effective option for seizure control in patients with TSC-related epilepsy. The identification of preoperative risk factors for seizure outcome could be helpful for optimizing patients' selection for surgery and pre-surgical counseling., (Copyright © 2022. Published by Elsevier Ltd.)

Purpose: To define Stereo-EEG (SEEG) ictal and interictal patterns associated with different pathologies in a cohort of patients with drug-resistant focal epilepsy., Methods: We retrospectively analyzed findings from 102 patient with epilepsy due to Polymicrogyria (PMG), Periventricular Nodular Heterotopia (PNH), Focal Cortical Dysplasia (FCD) type I, IIa, IIb and Hippocampal Sclerosis (HS). Ictal and interictal SEEG recordings were reviewed to describe Seizure Onset Zone (SEEG-SOZ) patterns and to define the Lesional and Irritative Zones., Results: Five SEEG-SOZ patterns were identified: significant associations were found between low-voltage fast activity and PMG and between repetitive fast spikes bursts and FCD type IIa. A trend was found between fast activity and PNH, rhythmic sharp activity and FCD type I, repetitive fast spikes bursts and FCD type IIb, slow burst and HS. In 62 of the 102 patients, a complete surgical resection of the SEEG-SOZ was performed, and in 12 patients a partial resection was carried out to preserve eloquent areas. In 18 patients (15 with PNH) the SEEG-SOZ was thermo-coagulated. Seizure freedom was achieved in 58% of surgically treated patients and in 72% of those treated with thermocoagulation (mean ± SD follow-up 5.9 ± 2.3 years). Seizure freedom after surgery was achieved in 84% of the patients with PMG, FCD I, IIa and IIb presenting with characteristic SEEG-SOZ patterns. With the exception of FCD type II, interictal activity was not sufficient to identify SEEG-SOZ boundaries., Conclusion: The study demonstrates that specific histopathologies correlate with particular neurophysiological patterns, reflecting lesion-specific seizure patterns in focal epilepsies., (Copyright © 2019 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: Surgery is an effective treatment for drug resistant focal epilepsy. Predictors of seizure outcome have been extensively addressed in the general population but similar data on older patients are still lacking. The aim of this study is to evaluate effectiveness and safety of surgery for patients over 50 years and to investigate variables associated to seizure outcome., Methods: We performed a single center retrospective study including 50 patients over 50 years treated surgically for drug resistant focal epilepsy between 1997 and 2014. We analyzed the rate of success of seizure control, the association of several clinical variables with seizure outcome and the rate of surgery-related complications. We also investigated the impact of surgery on the patients' cognitive performances and mood profile., Results: At last follow-up 78% of our patients were seizure-free, similar to patients younger than 50 years operated on in the same period (p=1). The rate of surgery-related complications was 10%, higher compared to younger patients (p<0.0001). Pre-surgical daily seizure frequency (p=0.0040) and the histological diagnosis of LEAT (p=0.0233) were associated to a poorer seizure outcome. No significant differences were evidenced between pre- and postoperative neuropsychological profiles. A slight, not statistically significant improvement of the mood profile was observed postoperatively., Conclusion: Our results suggest that surgery is an effective treatment option also for older epileptic patients, although it is burdened by a higher surgical risk as compared to younger patients. The availability of predictors of outcome also for these patients may be helpful for pre-surgical counseling., (Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: Temporal lobe epilepsy (TLE) with bilateral ictal involvement (bitemporal epilepsy, BTLE) is an intriguing form of TLE whose characteristics need to be carefully identified as BTLE patients are not good surgical candidates. The purpose of this study was to define the anatomo-electro-clinical features differentiating BTLE from unilateral TLE (UTLE)., Methods: Forty-eight BTLE patients underwent long-term video-EEG monitoring (VEEG) and experienced seizures with bilateral temporal lobe involvement. Their main electro-clinical (demographics, interictal and ictal EEG, ictal signs) and neuro-imaging [brain magnetic resonance imaging (MRI)] data were compared with those of a group of 38 UTLE patients., Results: In comparison with the UTLE patients, the BTLE cohort was significantly older at the time of epilepsy onset (p = 0.023), more frequently experienced bilateral asynchronous interictal epileptiform discharges during wakefulness (p = 0.001) and sleep (p < 0.001), bilateral upper limb dystonia (p = 0.005), and auditory auras (p = 0.027), and less frequently showed a recognisable initial ictal EEG pattern of focal flattening or low-voltage fast activity (p < 0.001), post-ictal memory of seizures (p = 0.001), staring (p < 0.001), head deviation (p = 0.004), oro-alimentary automatisms (p = 0.006), and positive brain MRI (p < 0.001). MRI revealed neoplastic lesions (p = 0.007) or alterations other than hippocampal sclerosis (p = 0.028) only in the UTLE patients., Conclusion: The possibility of recognising BTLE patients during pre-surgical evaluation or being able to suspect bitemporal seizures before VEEG by identifying particular anatomo-electro-clinical patterns is diagnostically important for epileptologists and can help to prevent possible surgical failures., (Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

The primary angiitis of the central nervous system (PACNS) is a rare and potentially fatal form of vasculitis with unknown etiology. Headache and encephalopathy are the most frequent symptoms. Neuroimaging plays an important role in the diagnosis, but the pattern of abnormal findings is not specific. In some cases brain biopsy is mandatory. PACNS is often described as a diagnostic and therapeutic challenge for clinicians considering the lack of univocal diagnostic criteria and paucity of studies evaluating the long-term outcome. This brief work reports how we managed eight patients with PACNS from diagnosis to long-term follow up treatment. Headache and focal acute neurological deficits were the most common symptoms. Magnetic resonance imaging (MRI) was abnormal in all patients with different patterns of infarctions or intraparenchymal/subarachnoid hemorrhages or their combination. Cerebral angiography demonstrated pathological findings compatible with vasculitis in all cases. Other causes of encephalopathy were ruled out. Patients with severe clinical and neuroradiological findings were treated with steroids and immunosuppressive therapy using cyclophosphamide/methotrexate. Patients with less aggressive PACNS, were treated with steroids only. In one case with multiple relapses infliximab was used after first-line immunosuppressive therapy failure. PACNS suspicion is based on the combination of demographic/clinical and MRI findings and the exclusion of other causes of multifocal encephalopathy. A positive angiography has a diagnostic value in an adequate clinical field. A strict collaboration of neurologists, neuroradiologists, and immunoreumatologists is essential in the management of PACNS both in the diagnostic and therapeutic phases., (Copyright © 2011 Elsevier B.V. All rights reserved.)