OBJECTIVE:  The objective of this study is to determine and compare the relationship of the most common psychiatric comorbidities in Bulgarian patients with epilepsy with the main clinical characteristics, as well as to evaluate their impact on certain aspects of the quality of life.
OBJECTIVE:  Psychiatric comorbidities occur in about one-third of people with epilepsy throughout their lifetime, and their incidence is much greater in high-risk groups such as patients with treatment-resistant epilepsy.
METHODS:  The study group consisted of 129 participants, of whom 104 were divided into four groups according to the presence of one of the most frequently diagnosed psychiatric comorbidities in our patients with epilepsy: personality and behavioral disorder (PBD) (n=25), mild to moderate depressive disorder (n=26), anxiety disorder (n=32), and dissociative and conversion disorders (n=21). A control group was also formed with a similar number of participants with epilepsy (n=25) without psychiatric comorbidity. Some sociodemographic and clinical characteristics of epilepsy were analyzed in all patients. All patients filled out two questionnaires: the Bulgarian version of quality of life in epilepsy - 89 (QOLIE-89) and the Bulgarian version of SIDAED (assessing SIDe effects in antiepileptic drugs (AED) treatment).
RESULTS:  The analysis revealed a negative influence of psychiatric comorbidity on the presence of epileptic seizures, unwanted drug effects, and lower scores for all aspects of the quality of life of patients with epilepsy.
CONCLUSIONS:  The main conclusion of our study is the presence of an interaction between psychiatric comorbidity, the clinical course of the disease, and the deteriorated quality of life (QOL) in patients with epilepsy. Further attention, comprehensive care, and targeted research are needed to analyze individual psychiatric comorbidities in patients with epilepsy for early detection and treatment.

BACKGROUND: There is no standardized EEG duration guideline for detecting epileptiform abnormalities in patients, and research on this topic is scarce. This study aims to determine an optimal EEG duration for efficient detection of epileptiform abnormalities across different patient groups.
METHODS: Retrospective analysis was performed on EEG recordings and clinical data of patients with the first seizure and epilepsy. Patients were categorized based on various factors, including the interval time since the last seizure, use of anti-seizure medication (ASM), and seizure frequency. The detection ratio (DR) of epileptiform abnormalities and latency time for their discovery were calculated. Statistical analyses, including chi-square tests, logistic regression, and survival analysis were utilized to illustrate DR and latency times.
RESULTS: In whole-night EEG recordings, the DR was 37.6% for the first seizure group and 57.4% for the epilepsy group. Although the maximum latency times were 720 min in both two groups, DR in the first seizure group was distinctly decreased beyond 300 min. Significant factors influencing the DR included the use of ASM in the first seizure group (P < 0.05) and seizure frequency in the epilepsy group (P < 0.001). For epilepsy patients who experience a seizure at least once a month or undergo timely EEG recordings (within 24 h after a seizure), the DR significantly increases, and the maximum latency time is reduced to 600 min (P < 0.001). Additionally, the DR was significantly reduced after 240 min in epilepsy patients who had been seizure-free for more than one year.
CONCLUSIONS: In this retrospective study, we observed a maximum latency of 720 min for detecting epileptiform abnormalities in whole-night EEG recordings. Notably, epilepsy patients with a higher seizure frequency or timely EEG recordings demonstrated both a higher detection ratio and a shorter maximum latency time. For patients exhibiting a low detection ratio, such as those experiencing their first seizure or those with epilepsy who have been seizure-free for more than a year, a shorter EEG duration is recommended. These findings underscore the importance of implementing customized EEG strategies to meet the specific needs of different patient groups.

OBJECTIVE: Dravet syndrome is a rare developmental epilepsy syndrome associated with severe, treatment-resistant seizures. Since seizures and seizure clusters are linked to morbidity, reduced quality of life, and premature mortality, a greater understanding of these outcomes could improve trial designs. This analysis explored seizure types, seizure clusters, and factors affecting seizure cluster variability in Dravet syndrome patients.
METHODS: Pooled post-hoc analyses were performed on data from placebo-treated patients in GWPCARE 1B and GWPCARE 2 randomized controlled phase III trials comparing cannabidiol and placebo in Dravet syndrome patients aged 2-18 years. Multivariate stepwise analysis of covariance of log-transformed convulsive seizure cluster frequency was performed, body weight and body mass index z-scores were calculated, and incidence of adverse events was assessed. Data were summarized in three age groups.
RESULTS: We analyzed 124 placebo-treated patients across both studies (2-5 years: n = 35; 6-12 years: n = 52; 13-18 years: n = 37). Generalized tonic-clonic seizures followed by myoclonic seizures were the most frequent seizure types. Mean and median convulsive seizure cluster frequency overall decreased between baseline and maintenance period but did not change significantly during the latter; variation in convulsive seizure cluster frequency was observed across age groups. Multivariate analysis suggested correlations between convulsive seizure cluster frequency and age (positive), and body mass index (BMI) (negative).
CONCLUSIONS: Post-hoc analyses suggested that potential relationships could exist between BMI, age and convulsive seizure cluster variation. Results suggested that seizure cluster frequency may be a valuable outcome in future trials. Further research is needed to confirm our findings.

BACKGROUND: Dravet Syndrome (DS) is a rare and severe form of childhood epilepsy that is often refractory to conventional antiepileptic drugs. Emerging evidence suggests that Cannabidiol (CBD) offer therapeutic benefits for DS. This review aims to evaluate the efficacy and safety of CBD in pediatric patients with DS based on data from ten clinical trials.
METHODS: A review was conducted to identify clinical trials assessing the efficacy and safety of CBD in pediatric patients diagnosed with DS. PubMed, MEDLINE, Scopus, Web of Science, and relevant grey literature were systematically searched for relevant articles up to October 2023, and clinical trials within the last 10 years were included. The search strategy incorporated controlled vocabulary terms and keywords related to \"Cannabidiol,\" \"Dravet Syndrome,\" and \"pediatric patients.\"
RESULTS: The analysis revealed promising efficacy outcomes. Notably, CBD demonstrated substantial reductions in seizure frequency, with some patients achieving seizure freedom. The findings emphasised the consistency of CBD\'s efficacy across different patient subgroups. The safety profile of CBD was generally acceptable, with adverse events often being manageable.
CONCLUSIONS: This review consolidates evidence from multiple clinical trials, affirming the potential of CBD as a promising treatment option for pediatric patients with DS. While further research is needed to address existing knowledge gaps, CBD\'s efficacy and acceptable safety profile make it a valuable addition to the therapeutic tools for DS.

BACKGROUND: Antiseizure medication (ASM) shortages are a global problem that have a negative impact on outcomes such as seizure control in patients with epilepsy (PWE). In the case of clobazam (CLB) shortage, there is no study regarding the management strategy. This study aims to investigate the alteration in seizure frequency and the occurrence of side effects in PWE undergoing an abrupt switch from clobazam (CLB) to clonazepam (CLZ), during CLB shortage.
METHODS: A retrospective study was conducted from electronic health records at our neurology outpatient clinic from January to July 2022. Change in seizure frequency and percentage of CLZ-associated side effects were determined as primary and secondary outcomes, respectively. Potential drug-drug interactions (Level C and above) were evaluated by using Lexicomp Drug Interaction Checker.
RESULTS: The analysis included a total of 29 adult patients (15F, median age: 29). The switching ratio was 10 mg CLB for every 1 mg CLZ (10:1). Seizure frequency was higher during the CLZ period compared to the CLB period (p < 0.05), but no status epilepticus cases were observed. All patients exhibited potential drug-drug interactions, leading to reduced CLZ levels in 12 cases. A total of 36 CLZ-associated side effects were identified, with fatigue (19.4 %), drowsiness (16.6 %), and somnolence (13.8 %) being the most prevalent. A positive and strong correlation was found between CLZ dose and the number of side effects (r: 0.556; p: 0.002).
CONCLUSIONS: The abrupt switch from CLB to CLZ was observed to increase seizure frequency without leading to status epilepticus in PWE. CLZ-associated side effects were found to be tolerable despite the abrupt switch. Future studies may explore the effect of alternative switching ratios.

BACKGROUND: We compared dissociative seizure specific cognitive behavior therapy (DS-CBT) plus standardized medical care (SMC) to SMC alone in a randomized controlled trial. DS-CBT resulted in better outcomes on several secondary trial outcome measures at the 12-month follow-up point. The purpose of this paper is to evaluate putative treatment mechanisms.
METHODS: We carried out a secondary mediation analysis of the CODES trial. 368 participants were recruited from the National Health Service in secondary / tertiary care in England, Scotland, and Wales. Sixteen mediation hypotheses corresponding to combinations of important trial outcomes and putative mediators were assessed. Twelve-month trial outcomes considered were final-month seizure frequency, Work and Social Adjustment Scale (WSAS), and the SF-12v2, a quality-of-life measure providing physical (PCS) and mental component summary (MCS) scores. Mediators chosen for analysis at six months (broadly corresponding to completion of DS-CBT) included: (a) beliefs about emotions, (b) a measure of avoidance behavior, (c) anxiety and (d) depression.
RESULTS: All putative mediator variables except beliefs about emotions were found to be improved by DS-CBT. We found evidence for DS-CBT effect mediation for the outcome variables dissociative seizures (DS), WSAS and SF-12v2 MCS scores by improvements in target variables avoidance behavior, anxiety, and depression. The only variable to mediate the DS-CBT effect on the SF-12v2 PCS score was avoidance behavior.
CONCLUSIONS: Our findings largely confirmed the logic model underlying the development of CBT for patients with DS. Interventions could be additionally developed to specifically address beliefs about emotions to assess whether it improves outcomes.

OBJECTIVE: To report the efficacy, safety, and tolerability of adjunctive eslicarbazepine acetate (ESL) treatment in reducing focal to bilateral tonic-clonic seizures (FBTCS).
METHODS: Data were pooled from 3 randomized clinical trials (RCTs) of adjunctive ESL in patients with focal seizures. Patients treated with 800 or 1200 mg/day ESL and who experienced ≥ 1 FBTCS during baseline were included. Efficacy was measured using FBTCS standardized seizure frequency (SSF), responder rates (≥50%, ≥75%, and 100%), and time to first FBTCS. Adverse events (AEs) were tabulated for each subgroup.
RESULTS: Of the original 1447 patients, 438 patients in the safety population were included with ≥ 1 FBTCS at baseline (efficacy population, n = 429). Patients with ≥ 2 FBTCS (safety, n = 354; efficacy, n = 346) and ≥ 3 FBTCS (safety, n = 294; efficacy, n = 288) at baseline were also analyzed. The 1200 mg/day ESL group experienced lower least squares mean SSF vs placebo in patients with ≥ 1 baseline FBTCS (P = 0.0395) and ≥ 3 baseline FBTCS (P = 0.0091). The 50% responder rates improved for 1200 mg/day ESL vs placebo (≥1 FBTCS, P = 0.005; ≥2 FBTCS, P = 0.0063; ≥3 FBTCS, P = 0.0016). The 75% responder rates improved with 1200 mg/day ESL vs placebo (≥1 FBTCS, P = 0.0315; ≥2 FBTCS, P = 0.0215; ≥3 FBTCS, P = 0.0099), and with 800 mg/day ESL for ≥ 2 FBTCS at baseline (P = 0.0486). The 100% responder rate was higher in patients treated with 1200 mg/day ESL (not significant). Time to first FBTCS was longer with both 800 (P = 0.0008) and 1200 mg/day (P = 0.0020) ESL vs placebo for the ≥ 1 FBTCS subgroup, and with 1200 mg/day ESL for ≥ 2 FBTCS (P = 0.0060) and ≥ 3 FBTCS (P = 0.0152) subgroups. Overall, AEs occurred at similar rates across subgroups, and were lower than the original RCTs.
CONCLUSIONS: Adjunctive ESL produced a robust response in patients with FBTCS, a seizure type associated with SUDEP and high injury rates. Adjunctive ESL was well tolerated in patients who experienced FBTCS.

BACKGROUND: This study was performed to test the hypothesis that systemic leukocyte gene expression has prognostic value differentiating low from high seizure frequency refractory temporal lobe epilepsy (TLE).
METHODS: A consecutive series of patients with refractory temporal lobe epilepsy was studied. Based on a median baseline seizure frequency of 2.0 seizures per month, low versus high seizure frequency was defined as ≤ 2 seizures/month and > 2 seizures/month, respectively. Systemic leukocyte gene expression was analyzed for prognostic value for TLE seizure frequency. All differentially expressed genes were analyzed, with Ingenuity® Pathway Analysis (IPA®) and Reactome, to identify leukocyte gene expression and biological pathways with prognostic value for seizure frequency.
RESULTS: There were ten males and six females with a mean age of 39.4 years (range: 16 to 62 years, standard error of mean: 3.6 years). There were five patients in the high and eleven patients in the low seizure frequency cohorts, respectively. Based on a threshold of twofold change (p < 0.001, FC > 2.0, FDR < 0.05) and expression within at least two pathways from both Reactome and Ingenuity® Pathway Analysis (IPA®), 13 differentially expressed leukocyte genes were identified which were all over-expressed in the low when compared to the high seizure frequency groups, including NCF2, HMOX1, RHOB, FCGR2A, PRKCD, RAC2, TLR1, CHP1, TNFRSF1A, IFNGR1, LYN, MYD88, and CASP1. Similar analysis identified four differentially expressed genes which were all over-expressed in the high when compared to the low seizure frequency groups, including AK1, F2R, GNB5, and TYMS.
CONCLUSIONS: Low and high seizure frequency TLE are predicted by the respective upregulation and downregulation of specific leukocyte genes involved in canonical pathways of neuroinflammation, oxidative stress and lipid peroxidation, GABA (γ-aminobutyric acid) inhibition, and AMPA and NMDA receptor signaling. Furthermore, high seizure frequency-TLE is distinguished prognostically from low seizure frequency-TLE by differentially increased specific leukocyte gene expression involved in GABA inhibition and NMDA receptor signaling. High and low seizure frequency patients appear to represent two mechanistically different forms of temporal lobe epilepsy based on leukocyte gene expression.

OBJECTIVE: Statistical learning, the fundamental cognitive ability of humans to extract regularities across experiences over time, engages the medial temporal lobe (MTL) in the healthy brain. This leads to the hypothesis that statistical learning (SL) may be impaired in patients with epilepsy (PWE) involving the temporal lobe, and that this impairment could contribute to their varied memory deficits. In turn, studies done in collaboration with PWE, that evaluate the necessity of MTL circuitry through disease and causal perturbations, provide an opportunity to advance basic understanding of SL.
METHODS: We implemented behavioral testing, volumetric analysis of the MTL substructures, and direct electrical brain stimulation to examine SL across a cohort of 61 PWE and 28 healthy controls.
RESULTS: We found that behavioral performance in an SL task was negatively associated with seizure frequency irrespective of seizure origin. The volume of hippocampal subfields CA1 and CA2/3 correlated with SL performance, suggesting a more specific role of the hippocampus. Transient direct electrical stimulation of the hippocampus disrupted SL. Furthermore, the relationship between SL and seizure frequency was selective, as behavioral performance in an episodic memory task was not impacted by seizure frequency.
CONCLUSIONS: Overall, these results suggest that SL may be hippocampally dependent and that the SL task could serve as a clinically useful behavioral assay of seizure frequency that may complement existing approaches such as seizure diaries. Simple and short SL tasks may thus provide patient-centered endpoints for evaluating the efficacy of novel treatments in epilepsy.

OBJECTIVE: To evaluate outcomes from hemispherectomy and callosotomy related to the need for anti-seizure medication (ASM), seizure frequency, and cognition.
METHODS: A review of the medical charts of all Danish pediatric patients who underwent hemispherectomy or callosotomy from January 1996 to December 2019 for preoperative and postoperative ASM use, seizure frequency, and cognitive data.
RESULTS: The median age of epilepsy onset was two years (interquartile range (IQR): 0.0-5.3) for the hemispherectomy patients (n = 16) and one year (IQR: 0.6-1.7) for callosotomy patients (n = 5). Median time from onset to final surgery was 3.4 years for hemispherectomy and 10.2 years for callosotomy, while the median follow-up time was 6.9 years and 9.0 years, respectively. Preoperatively, all patients had daily seizures and were treated with ≥ 2 ASM. Hemispherectomy resulted in a reduction in seizure frequency in 87.5 % of patients, with 78.6 % achieving seizure freedom. Furthermore, 81.3 % experienced a reduction in ASM use and 56.3 % stopped all ASM. Median IQ/developmental quotient (IQ/DQ) was low preoperatively (44.0 [IQR: 40.0-55.0]) and remained unchanged postoperatively (IQ change: 0.0 [IQR: -10.0-+4.0]). Callosotomy resulted in a seizure reduction of 86-99 % in four patients, and ASM could be reduced in three patients. Median IQ/DQ was 20.0 preoperatively (IQR: 20.0-30.0) and remained unchanged postoperatively (IQ change: 0.0 [IQR: 0.0]).
CONCLUSIONS: Hemispherectomy and callosotomy result in a substantial reduction in seizure frequency and ASM use without deterioration of IQ. Extensive epilepsy surgery should be considered early in children with drug-resistant epilepsy.