Stereo-electroencephalography (SEEG) is the gold standard to delineate surgical targets in focal drug-resistant epilepsy. SEEG uses electrodes placed directly into the brain to identify the seizure-onset zone (SOZ). However, its major constraint is limited brain coverage, potentially leading to misidentification of the \'true\' SOZ. Here, we propose a framework to assess adequate SEEG sampling by coupling epileptic biomarkers with their spatial distribution and measuring the system\'s response to a perturbation of this coupling. We demonstrate that the system\'s response is strongest in well-sampled patients when virtually removing the measured SOZ. We then introduce the spatial perturbation map, a tool that enables qualitative assessment of the implantation coverage. Probability modelling reveals a higher likelihood of well-implanted SOZs in seizure-free patients or non-seizure free patients with incomplete SOZ resections, compared to non-seizure-free patients with complete resections. This highlights the framework\'s value in sparing patients from unsuccessful surgeries resulting from poor SEEG coverage.

BACKGROUND: At least 20% of paediatric patients with epilepsy present resistance to multiple anti-crisis drugs in trials, which has a negative impact on their neuropsychological state, quality of life and prognosis; it is therefore necessary to document their neuropsychological profile in order to improve the clinical approach to them.
OBJECTIVE: To describe the neuropsychological profile (cognitive, academic, behavioural, emotional, adaptive, sleep disturbances and quality of life) of paediatric patients with drug-resistant focal epilepsy in the frontal, temporal and occipital lobes, and to compare performance between patients with frontal and temporal foci, and to assess the link between the duration of the condition, the frequency of seizures and the amount of anti-crisis drugs and the neuropsychological profile.
METHODS: The neuropsychological profile of 19 paediatric patients with a diagnosis of pharmacoresistant epilepsy with a mean age of 10.89 years was evaluated.
RESULTS: 57.9% of the 19 patients were men. 63.2% presented frontal focus; 26.3% presented temporal focus; and 10.5% presented occipital focus. Deficiencies in attention, comprehension, verbal memory, working memory and processing speed, in addition to adaptive difficulties were observed. When the patients with frontal and temporal focus were compared, the former were found to present greater deficits in planning, while the patients with temporal focus presented more severe symptoms of anxiety. Patients with a longer disease duration were found to present greater impairment to their intelligence quotient and adaptive behavioural skills.
CONCLUSIONS: Pharmacoresistant epilepsy in paediatric patients affects intelligence quotient and adaptive skills, as well as attention, memory and executive functions, and neuropsychological intervention programmes must therefore be implemented to improve these patients\' quality of life.
BACKGROUND: Perfil neuropsicológico de pacientes pediátricos mexicanos con epilepsia focal farmacorresistente.
Introducción. Al menos el 20% de los pacientes pediátricos con epilepsia muestra resistencia a los ensayos de múltiples fármacos anticrisis, que impactan negativamente en su estado neuropsicológico, calidad de vida y pronóstico; por tal motivo, es necesario documentar ampliamente su perfil neuropsicológico para mejorar su abordaje clínico. Objetivos. Describir el perfil neuropsicológico (cognitivo, académico, conductual, emocional, adaptativo, alteraciones del sueño y calidad de vida) de pacientes pediátricos con epilepsia focal farmacorresistente de los lóbulos frontal, temporal y occipital, así como comparar el desempeño entre los pacientes con foco frontal y temporal, y evaluar la asociación entre la duración del padecimiento, la frecuencia de las crisis y la cantidad de fármacos anticrisis con el perfil neuropsicológico. Pacientes y métodos. Se evaluó el perfil neuropsicológico de 19 pacientes pediátricos con diagnóstico de epilepsia farmacorresistente, con una edad promedio de 10,89 años. Resultados. De los 19 pacientes, el 57,9% fueron hombres. El 63,2% presentó foco frontal; el 26,3%, temporal; y el 10,5%, occipital. Se encontraron deficiencias en atención, comprensión, memoria verbal, memoria de trabajo y velocidad de procesamiento, además de dificultades adaptativas. Al comparar a los pacientes con foco frontal y temporal, se encontró que los primeros presentaron mayores deficiencias en planificación, mientras que los pacientes con foco temporal presentaron mayores síntomas de ansiedad. Con respecto a la duración de la enfermedad, se encontró que los pacientes con mayor duración del padecimiento presentaron mayor afectación en el cociente intelectual y en las habilidades en la conducta adaptativa. Conclusiones. La epilepsia farmacorresistente en pacientes pediátricos afecta el cociente intelectual y las habilidades adaptativas, así como a la atención, la memoria y las funciones ejecutivas, por lo que es necesaria la implementación de programas de intervención neuropsicológica para mejorar la calidad de vida de estos pacientes.

We revisited the anatomo-functional characteristics of the basal temporal language area (BTLA), first described by Lüders et al. (1986), using electrical cortical stimulation (ECS) in the context of Japanese language and semantic networks. We recruited 11 patients with focal epilepsy who underwent chronic subdural electrode implantation and ECS mapping with multiple language tasks for presurgical evaluation. A semiquantitative language function density map delineated the anatomo-functional characteristics of the BTLA (66 electrodes, mean 3.8 cm from the temporal tip). The ECS-induced impairment probability was higher in the following tasks, listed in a descending order: spoken-word picture matching, picture naming, Kanji word reading, paragraph reading, spoken-verbal command, and Kana word reading. The anterior fusiform gyrus (FG), adjacent anterior inferior temporal gyrus (ITG), and the anterior end where FG and ITG fuse, were characterized by stimulation-induced impairment during visual and auditory tasks requiring verbal output or not, whereas the middle FG was characterized mainly by visual input. The parahippocampal gyrus was the least impaired of the three gyri in the basal temporal area. We propose that the BTLA has a functional gradient, with the anterior part involved in amodal semantic processing and the posterior part, especially the middle FG in unimodal semantic processing.

Correctly diagnosing and classifying seizures and epilepsies is vital to ensure a tailored approach to patients with epilepsy. The ILAE seizure classification consists of two main groups: focal and generalized. Establishing if a seizure is focal or generalized is essential to classify the epilepsy type and the epilepsy syndrome, providing more personalized treatment and counseling about prognosis. EEG is one of the most essential tools for this classification process and further localization of the epileptogenic focus. However, some EEG findings are misleading and may postpone the correct diagnosis and proper treatment. Knowing the most common EEG pitfalls in focal and generalized epilepsies is valuable for clinical practice, avoiding misinterpretations. Some atypical features can be challenging in focal epilepsies, such as secondary bilateral synchrony, focal epileptiform activity induced by hyperventilation and photic stimulation, and non-focal slowing. On the other hand, more than 60 % of persons with idiopathic generalized epilepsies have at least one type of atypical abnormality. In this manuscript, we describe and illustrate some of the most common EEG findings that can make even experienced epileptologists question not only where the epileptogenic focus is but also if the patient has focal or generalized epilepsy. This review summarizes the perils and provide some pearls to assist EEG readers.

OBJECTIVE: Individuals with epilepsy have increased risk of suicidal ideation (SI) and behaviors when compared with the general population. This relationship has remained largely unexplored in adolescents. We investigated the prevalence of suicidality in adolescents with newly diagnosed focal epilepsy within 4 months of treatment initiation and over the following 36 months.
METHODS: This was a post hoc analysis of the enrollment and follow-up data from the Human Epilepsy Project, an international, multi-institutional study that enrolled participants between 2012 and 2017. Participants enrolled were 11-17 years of age within 4 months of treatment initiation for focal epilepsy. We used data from the Columbia Suicide Severity Rating Scale (C-SSRS), administered at enrollment and over the 36-month follow-up period, along with data from medical records.
RESULTS: A total of 66 adolescent participants were enrolled and completed the C-SSRS. At enrollment, 14 (21%) had any lifetime SI and 5 (8%) had any lifetime suicidal behaviors (SBs). Over the following 36 months, 6 adolescents reported new onset SI and 5 adolescents reported new onset SB. Thus, the lifetime prevalence of SI within this population increased from 21% to 30% (14-20 adolescents), and the lifetime prevalence of SB increased from 8% to 15% (5-10).
CONCLUSIONS: The prevalence of suicidality in adolescents with newly diagnosed focal epilepsy reported in our study is consistent with previous findings of significant suicidality observed in epilepsy. We identify adolescents as an at-risk population at the time of epilepsy diagnosis and in the following years.

OBJECTIVE: Parietal lobe epilepsy (PLE) surgery can be an effective treatment for selected patients with intractable epilepsy but can be associated with the risk of serious neurologic deficits. We performed a systematic review of the literature to obtain a comprehensive summary of the frequency and types of new postoperative neurologic deficits in patients undergoing PLE resective surgery.
METHODS: We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials for articles published between January 1, 1990, and April 28, 2022. We included studies that reported postoperative neurologic outcome following PLE resective surgery confined to the parietal lobe. We required that studies included ≥5 patients. The data collected included demographic information and specific details of postoperative neurologic deficits. When available, individual patient data were collected. We used the Risk of Bias in Nonrandomized Studies of Interventions tool to assess the risk of bias and Grading of Recommendations Assessment, Development, and Evaluation to assess the quality of the evidence.
RESULTS: Of the 3,461 articles screened, 33 studies met the inclusion criteria. A total of 370 patients were included. One hundred patients (27.0%) had a new deficit noted postoperatively. Approximately half of the patients with deficits experienced only transient deficits. Motor deficits were the most commonly identified deficit. The rates of motor deficits noted after PLE surgery were 5.7%, 3.2%, and 2.2% for transient, long-term, and duration not specified, respectively. Sensory and visual field deficits were also commonly reported. Gerstmann syndrome was noted postoperatively in 4.9% of patients and was almost always transient. Individual patient data added information on parietal lobe subregion postoperative neurologic outcome.
CONCLUSIONS: Our systematic review provides a comprehensive summary of the frequency and types of neurologic deficits associated with PLE surgery. A significant percentage of postoperative deficits are transient. In addition to the expected sensory and visual deficits, PLE surgery is associated with a notable risk of motor deficits. The available literature has important deficiencies. Our study highlights gaps in the literature and provides recommendations for future directions.
UNASSIGNED: This systematic review was registered on PROSPERO (CRD42022313108, May 26, 2022).

OBJECTIVE: Microstates represent the global and topographical distribution of electrical brain activity from scalp-recorded EEG. This study aims to explore EEG microstates of patients with focal epilepsy prior to medication, and employ extracted microstate metrics for predicting treatment outcomes with Oxcarbazepine monotherapy.
METHODS: This study involved 25 newly-diagnosed focal epilepsy patients (13 females), aged 12 to 68, with various etiologies. Patients were categorized into Non-Seizure-Free (NSF) and Seizure-Free (SF) groups according to their first follow-up outcomes. From pre-medication EEGs, four representative microstates were identified by using clustering. The temporal parameters and transition probabilities of microstates were extracted and analyzed to discern group differences. With generating sample method, Support Vector Machine (SVM), Logistic Regression (LR), and Naïve Bayes (NB) classifiers were employed for predicting treatment outcomes.
RESULTS: In the NSF group, Microstate 1 (MS1) exhibited a significantly higher duration (mean±std. = 0.092±0.008 vs. 0.085±0.008, p = 0.047), occurrence (mean±std. = 2.587±0.334 vs. 2.260±0.278, p = 0.014), and coverage (mean±std. = 0.240±0.046 vs. 0.194±0.040, p = 0.014) compared to the SF group. Additionally, the transition probabilities from Microstate 2 (MS2) and Microstate 3 (MS3) to MS1 were increased. In MS2, the NSF group displayed a stronger correlation (mean±std. = 0.618±0.025 vs. 0.571±0.034, p < 0.001) and a higher global explained variance (mean±std. = 0.083±0.035 vs. 0.055±0.023, p = 0.027) than the SF group. Conversely, Microstate 4 (MS4) in the SF group demonstrated significantly greater coverage (mean±std. = 0.388±0.074 vs. 0.334±0.052, p = 0.046) and more frequent transitions from MS2 to MS4, indicating a distinct pattern. Temporal parameters contribute major predictive role in predicting treatment outcomes of Oxcarbazepine, with area under curves (AUCs) of 0.95, 0.70, and 0.86, achieved by LR, NB and SVM, respectively.
CONCLUSIONS: This study underscores the potential of EEG microstates as predictive biomarkers for Oxcarbazepine treatment responses in newly-diagnosed focal epilepsy patients.

BACKGROUND: Accurate identification of abnormal electroencephalographic (EEG) activity is pivotal for diagnosing and treating epilepsy. Recent studies indicate that decomposing brain activity into periodic (oscillatory) and aperiodic (trend across all frequencies) components can illuminate the drivers of spectral activity changes.
METHODS: We analysed intracranial EEG (iEEG) data from 234 subjects, creating a normative map. This map was compared to a cohort of 63 patients with refractory focal epilepsy under consideration for neurosurgery. The normative map was computed using three approaches: (i) relative complete band power, (ii) relative band power with the aperiodic component removed, and (iii) the aperiodic exponent. Abnormalities were calculated for each approach in the patient cohort. We evaluated the spatial profiles, assessed their ability to localize abnormalities, and replicated the findings using magnetoencephalography (MEG).
RESULTS: Normative maps of relative complete band power and relative periodic band power exhibited similar spatial profiles, while the aperiodic normative map revealed higher exponent values in the temporal lobe. Abnormalities estimated through complete band power effectively distinguished between good and bad outcome patients. Combining periodic and aperiodic abnormalities enhanced performance, like the complete band power approach.
CONCLUSIONS: Sparing cerebral tissue with abnormalities in both periodic and aperiodic activity may result in poor surgical outcomes. Both periodic and aperiodic components do not carry sufficient information in isolation. The relative complete band power solution proved to be the most reliable method for this purpose. Future studies could investigate how cerebral location or pathology influences periodic or aperiodic abnormalities.

OBJECTIVE: We previously analyzed data from three phase lll trials of adjunctive brivaracetam (BRV) in adults showing that the incidence and prevalence of drug-related central nervous system treatment-emergent adverse events (TEAEs) quickly peaked and decreased over several weeks following BRV treatment initiation. However, that analysis did not assess psychiatric and behavioral side effects which can occur with antiseizure medication (ASM) treatment. Here, we investigate the time-course of psychiatric and behavioral TEAEs by week of BRV treatment and how these TEAEs were managed.
METHODS: Data were pooled from three trials (N01252 [NCT00490035]; N01253 [NCT00464269]; N01358 [NCT01261325]) in adult patients (≥16 years of age) with focal-onset seizures receiving BRV adjunctive therapy. This post hoc analysis reports data on the incidence and prevalence of drug-related psychiatric or behavioral TEAEs over time in patients who received BRV doses of 50-200 mg/day (without titration) or placebo (PBO) during the 12-week treatment period. A logistic regression model was used to determine if psychiatric or behavioral comorbid conditions were predictors for drug-related psychiatric or behavioral TEAEs, or BRV discontinuation due to psychiatric or behavioral TEAEs.
RESULTS: A total of 803 patients received BRV 50-200 mg/day, and 459 patients received PBO. Drug-related psychiatric or behavioral TEAEs were reported by 11.0 % of patients during adjunctive BRV treatment (PBO: 4.8 %) with onset early after BRV initiation (median time to onset of first drug-related psychiatric or behavioral TEAE: 15 days). Incidence peaked at week 1 and decreased over the first 4 weeks following BRV initiation. Prevalence peaked at week 4 and then remained stable between weeks 5-12. In an analysis excluding patients on concomitant levetiracetam (BRV: n = 744; PBO: n = 422), the incidence of drug-related psychiatric or behavioral TEAEs was similar to the incidence in the overall population. The most common drug-related psychiatric or behavioral TEAEs were irritability, insomnia, depression, and anxiety. Only 2 % of patients discontinued BRV due to psychiatric or behavioral TEAEs (PBO: 1.3 %), while most patients on BRV who reported drug-related psychiatric or behavioral TEAEs did not require a change in dose (84.1 %; PBO: 63.6 %). A history of psychiatric or behavioral comorbid conditions (not ongoing at BRV initiation) was not associated with an increased likelihood of drug-related psychiatric or behavioral TEAEs, or BRV discontinuation due to psychiatric or behavioral TEAEs. Ongoing psychiatric or behavioral comorbid conditions at BRV initiation increased the likelihood of drug-related psychiatric or behavioral TEAEs, but not the likelihood of BRV discontinuation due to psychiatric or behavioral TEAEs.
CONCLUSIONS: Drug-related psychiatric and behavioral TEAEs occurred early during BRV treatment, and most patients did not require a change in BRV dose. These data can help guide clinician monitoring and patient expectations after starting BRV.

A post hoc analysis of data from Asian patients included in the study BIA-2093-304 was conducted to evaluate the long-term safety/tolerability and efficacy of adjunctive eslicarbazepine acetate (ESL) in adult Asian patients with refractory focal seizures. Part I was a randomized controlled trial, in which patients received ESL (800 or 1200 mg once daily [QD]) or placebo, assessed over a 12-week maintenance period. Patients completing Part I could enter two open-label extension periods (Part II, 1 year; Part III, ≥2 years), during which all received ESL (400-1600 mg QD). Safety/tolerability was assessed by evaluating treatment-emergent adverse events (TEAEs). Efficacy assessments included responder and seizure freedom rates. The safety population included 125, 92, and 23 Asian patients in Parts I, II, and III, respectively. Incidence of ESL-related TEAEs was 61.3%, 45.7%, and 17.4% during Parts I, II, and III, respectively. ESL-related TEAEs (most commonly, dizziness, somnolence, and headache) were consistent with ESL\'s known safety profile. During Part I, responder rates were higher with ESL 800 (41.7%) and 1200 mg QD (44.4%) versus placebo (32.6%), although not statistically significant. Seizure freedom rates with ESL 800 (5.5%) and 1200 mg QD (11.1%) were also higher versus placebo (0%) (p < 0.05 for ESL 1200 mg QD versus placebo). At the end of Part II, responder and seizure freedom rates were 60.3% and 14.7%, respectively. In summary, adult Asian patients with refractory focal seizures were responsive to treatment with ESL as adjunctive therapy and generally showed treatment tolerance well for up to 3 years. No new/unexpected safety findings were observed.