Focal cortical dysplasia (FCD) is an important etiology of focal epilepsy in children and adults. However, only a few preclinical models sufficiently reproduce the characteristic histopathologic features of FCD. To improve the success rate of clinical trials for antiseizure medications (ASMs) in patients with FCD, more human-relevant preclinical models are needed, and epileptic foci resected from patients are a powerful tool for this purpose. Here, we conducted ex vivo studies using epileptic foci resected from patients with FCD type II to evaluate the pharmacologic effects of the ASM candidate E2730, a selective uncompetitive inhibitor of γ-aminobutyric acid transporter 1. We used the same ex vivo assay system to assess carbamazepine (CBZ), an ASM often prescribed for focal epilepsy, as a reference. At the higher dose tested (200 µM), both E2730 and CBZ suppressed spontaneous epileptiform activities almost completely. At the lower dose (100 µM), CBZ reduced the area of brain tissue showing epileptiform activity, whereas E2730 significantly decreased the number of epileptiforms. These findings suggest that E2730—both as a single agent and in combination with CBZ—merits evaluation in clinical trials involving patients with FCD.
An increasing number of Epilepsy Monitoring Units (EMU) display various practices and safety protocols. EMU settings should meet clear, standardized safety protocols to avoid seizure adverse events (SAE). We aim to provide the foundational framework facilitating the establishment of unified evidence-based safety regulations to address the practices and safety measures implemented within the Gulf Cooperation Council (GCC).
In this cross-sectional study, EMU directors in the GCC were contacted directly by phone to personally complete an electronic 37-item questionnaire sent via text messages and email. From January 2021–December 2021.
Seventeen EMUs from six GCC countries participated in the study. All EMU directors responded to the study. Twelve (70.6%) EMUs monitored adults and children, five (29.4%) monitored adults, and none monitored children only. The number of certified epileptologists in the EMUs ranged from one to eight per unit. Fifteen (88.2%) EMUs applied a continuous observation pattern, whereas two (11.8%) performed daytime only. The precautions most commonly used in the video Electroencephalogram (EEG) were seizure pads and bedside oxygen in 15 EMUs (88.2%). For invasive EEG, seizure pads were used in 9 EMUs (52.9%), %) and IV access in 8 EMUs (47.1%). The occurrence of adverse events varied among EMUs. The most common conditions were postictal psychosis 10 (58.8%), injuries 7 (41.2%), and status epilepticus 6 (35.3%). Falls were mainly related to missed seizures or delayed recognition by video monitors in 8 EMUs (47.1%). The extended EMU stay was because of an insufficient number of recorded seizures in 16 EMUs (94.1%), poor seizure lateralization and localization in 10 (58.8%), and re-introduction of AEDs in nine (52.9%). All EMUs had written acute seizure and status epilepticus management protocols. A postictal psychosis management protocol was available for 10 (58.8%). Medications were withdrawn before admission in 6 EMUs (35.3%). The specific medication withdrawal speed protocol upon admission was available in 7 EMUs (41.2%). Pre-admission withdrawal of medication demonstrated a shorter length of stay in both video and invasive EEG, which was statistically significant (ρ (15) = −.529, p =.029; ρ (7) = −.694, p =.038; respectively).
The practice and safety regulations of EMUs in the GCC vary widely. Each EMU reported the occurrences of SAE and injuries. Precautions, protective measures, and management protocols must be reassessed to minimize the number of SAEs and increase the safety of the EMU.
Early switch-over of anti-seizure medications (ASMs) from intravenous to oral route may reduce the duration of hospitalization, drug acquisition costs, and behavioral upset in hospitalized children with seizures.
The primary objective was to compare short-term seizure recurrence within 1 week in hospitalized children aged 1 month to 18 years with new-onset/breakthrough seizures after an early versus late switch-over from intravenous to the oral route of ASMs. Secondary objectives were to compare the incidence of status epilepticus, duration of hospital stay, drug acquisition costs, and caregiver-reported satisfaction scores in both groups.
In this single-blind randomized controlled trial, patients with seizures were categorized based on the number of ASMs required and the history of status epilepticus. Patients in each category were randomized in a 1:1 ratio into either early or late switch-over (ES or LS) groups. In the ES groups, ASMs were tapered one-by-one between 0 and 24 hours of seizure freedom, while in the LS groups, they were tapered one-by-one between 24 and 48 hours of seizure freedom.
A total of 112 children were enrolled in the study, with 56 in each arm. Seizure recurrence at 1 week and 12 weeks was comparable in ES and LS groups (3/55 vs. 1/54 at 1 week, p=0.61; 7/49 vs. 6/49 at 12 weeks, p=0.98). Drug acquisition costs were significantly lower in the ES group (393±274 vs. 658±568 INR, p=0.002). Thrombophlebitis and dysphoria were significantly more common in the LS group (p=0.008 and 0.03, respectively).
The early switch-over of ASMs from intravenous to oral route is safe without any significant increased risk of short-term seizure recurrence and also associated with a reduction in the incidence of thrombophlebitis and ASM acquisition costs.
CTRI/2021/03/032145
In developmental and epileptic encephalopathy with spike-and-wave activation in sleep (DEE-SWAS), the thalamocortical network is suggested to play an important role in the pathophysiology of the progression from focal epilepsy to DEE-SWAS. Ethosuximide (ESM) exerts effects by blocking T-type calcium channels in thalamic neurons. With the thalamocortical network in mind, we studied the prediction of ESM effectiveness in DEE-SWAS treatment using phase-amplitude coupling (PAC) analysis.
We retrospectively enrolled children with DEE-SWAS who had an electroencephalogram (EEG) recorded between January 2009 and September 2022 and were prescribed ESM at Okayama University Hospital. Only patients whose EEG showed continuous spike-and-wave during sleep were included. We extracted 5-min non-rapid eye movement sleep stage N2 segments from EEG recorded before starting ESM. We calculated the modulation index (MI) as the measure of PAC in pair combination comprising one of two fast oscillation types (gamma, 40–80 Hz; ripples, 80–150 Hz) and one of five slow-wave bands (delta, 0.5–1, 1–2, 2–3, and 3–4 Hz; theta, 4–8 Hz), and compared it between ESM responders and non-responders.
We identified 20 children with a diagnosis of DEE-SWAS who took ESM. Fifteen were ESM responders. Regarding gamma oscillations, significant differences were seen only in MI with 0.5–1 Hz slow waves in the frontal pole and occipital regions. Regarding ripples, ESM responders had significantly higher MI in coupling with all slow waves in the frontal pole region, 0.5–1, 3–4, and 4–8 Hz slow waves in the frontal region, 3–4 Hz slow waves in the parietal region, 0.5–1, 2–3, 3–4, and 4–8 Hz slow waves in the occipital region, and 3–4 Hz slow waves in the anterior-temporal region.
High MI in a wider area of the brain may represent the epileptic network mediated by the thalamus in DEE-SWAS and may be a predictor of ESM effectiveness.
Nonadherence to antiepileptic drugs (AEDs) is a prevalent issue in India, contributing to suboptimal seizure control, higher morbidity and mortality, increased hospitalization rates, and a substantial effect on the overall quality of life for individuals with epilepsy.
This study aimed to measure the prevalence of medication adherence among individuals with epilepsy in India and to identify factors associated with nonadherence.
Following PRISMA guidelines, we searched PubMed, Scopus, Embase, and Google Scholar for studies on AED adherence in India. Quality assessment employed Newcastle Ottawa Scale adapted for cross-sectional studies. Pooled prevalence was ascertained using a random-effects model in R software (version 4.2.2), with a 95% confidence interval. Heterogeneity was estimated with the I2 statistic, and publication bias was appraised via a funnel plot. Subgroup analyses, based on study region and adherence measurement tool, were done to investigate heterogeneity.
Nine cross-sectional studies with 1772 participants were analyzed. The pooled prevalence of adherence to AEDs in India stood at 49.9% (95% CI: 39.8%-60.1%). Subgroup analyses showed comparable adherence rates in the South (50.9%) and North (46.5%) regions of India. However, adherence rates varied substantially based on the measurement tool: Morisky Medication Adherence Scale-4 (MMAS-4) reported 71.3%, MMAS-8 indicated 45.9%, and Morisky Green Levine (MGL) adherence scale exhibited 42.0%. Factors contributing to non-adherence to antiepileptic therapies involved poor socioeconomic status, lower education levels, polytherapy, drug-related side effects, and substance abuse.
Almost half of persons with epilepsy in India were non-adherent to their AEDs. This underscores the importance for healthcare professionals to pay greater attention to improving the adherence rate to AEDs within the healthcare service.
Focal cortical dysplasias (FCDs) are a leading cause of drug-resistant epilepsy. Early detection and resection of FCDs have favorable prognostic implications for postoperative seizure freedom. Despite advancements in imaging methods, FCD detection remains challenging. House et al. (2021) introduced a convolutional neural network (CNN) for automated FCD detection and segmentation, achieving a sensitivity of 77.8%. However, its clinical applicability was limited due to a low specificity of 5.5%. The objective of this study was to improve the CNN’s performance through data-driven training and algorithm optimization, followed by a prospective validation on daily-routine MRIs.
A dataset of 300 3 T MRIs from daily clinical practice, including 3D T1 and FLAIR sequences, was prospectively compiled. The MRIs were visually evaluated by two neuroradiologists and underwent morphometric assessment by two epileptologists. The dataset included 30 FCD cases (11 female, mean age: 28.1 ± 10.1 years) and a control group of 150 normal cases (97 female, mean age: 32.8 ± 14.9 years), along with 120 non-FCD pathological cases (64 female, mean age: 38.4 ± 18.4 years). The dataset was divided into three subsets, each analyzed by the CNN. Subsequently, the CNN underwent a two-phase-training process, incorporating subset MRIs and expert-labeled FCD maps. This training employed both classical and continual learning techniques. The CNN’s performance was validated by comparing the baseline model with the trained models at two training levels.
In prospective validation, the best model trained using continual learning achieved a sensitivity of 90.0%, specificity of 70.0%, and accuracy of 72.0%, with an average of 0.41 false positive clusters detected per MRI. For FCD segmentation, an average Dice coefficient of 0.56 was attained. The model’s performance improved in each training phase while maintaining a high level of sensitivity. Continual learning outperformed classical learning in this regard.
Our study presents a promising CNN for FCD detection and segmentation, exhibiting both high sensitivity and specificity. Furthermore, the model demonstrates continuous improvement with the inclusion of more clinical MRI data. We consider our CNN a valuable tool for automated, examiner-independent FCD detection in daily clinical practice, potentially addressing the underutilization of epilepsy surgery in drug-resistant focal epilepsy and thereby improving patient outcomes.
Implantable brain recording and stimulation devices apply to a broad spectrum of conditions, such as epilepsy, movement disorders and depression. For long-term monitoring and neuromodulation in epilepsy patients, future extracranial subscalp implants may offer a promising, less-invasive alternative to intracranial neurotechnologies. To inform the design and assess the safety profile of such next-generation devices, we estimated extracranial complication rates of deep brain stimulation (DBS), cranial peripheral nerve stimulation (PNS), responsive neurostimulation (RNS) and existing subscalp EEG devices (sqEEG), as proxy for future implants. Pubmed was searched systematically for DBS, PNS, RNS and sqEEG studies from 2000 to February 2024 (48 publications, 7329 patients). We identified seven categories of extracranial adverse events: infection, non-infectious cutaneous complications, lead migration, lead fracture, hardware malfunction, pain and hemato-seroma. We used cohort sizes, demographics and industry funding as metrics to assess risks of bias. An inverse variance heterogeneity model was used for pooled and subgroup meta-analysis. The pooled incidence of extracranial complications reached 14.0%, with infections (4.6%, CI 95% [3.2 – 6.2]), surgical site pain (3.2%, [0.6 – 6.4]) and lead migration (2.6%, [1.0 – 4.4]) as leading causes. Subgroup analysis showed a particularly high incidence of persisting pain following PNS (12.0%, [6.8 – 17.9]) and sqEEG (23.9%, [12.7 – 37.2]) implantation. High rates of lead migration (12.4%, [6.4 – 19.3]) were also identified in the PNS subgroup. Complication analysis of DBS, PNS, RNS and sqEEG studies provides a significant opportunity to optimize the safety profile of future implantable subscalp devices for chronic EEG monitoring. Developing such promising technologies must address the risks of infection, surgical site pain, lead migration and skin erosion. A thin and robust design, coupled to a lead-anchoring system, shall enhance the durability and utility of next-generation subscalp implants for long-term EEG monitoring and neuromodulation.
The hyperpolarization-activated cyclic nucleotide-gated cation channel (HCN1) is predominantly located in key regions associated with epilepsy, such as the neocortex and hippocampus. Under normal physiological conditions, HCN1 plays a crucial role in the excitatory and inhibitory regulation of neuronal networks. In temporal lobe epilepsy, the expression of HCN1 is decreased in the hippocampi of both animal models and patients. However, whether HCN1 expression changes during epileptogenesis preceding spontaneous seizures remains unclear.
The aim of this study was to determine whether the expression of HCN1 is altered during the epileptic prodromal phase, thereby providing evidence for its role in epileptogenesis.
We utilized a cobalt wire-induced rat epilepsy model to observe changes in HCN1 during epileptogenesis and epilepsy. Additionally, we also compared HCN1 alterations in epileptogenic tissues between cobalt wire- and pilocarpine-induced epilepsy rat models. Long-term video EEG recordings were used to confirm seizures development. Transcriptional changes, translation, and distribution of HCN1 were assessed using high-throughput transcriptome sequencing, total protein extraction, membrane and cytoplasmic protein fractionation, western blotting, immunohistochemistry, and immunofluorescence techniques.
In the cobalt wire-induced rat epilepsy model during the epileptogenesis phase, total HCN1 mRNA and protein levels were downregulated. Specifically, the membrane expression of HCN1 was decreased, whereas cytoplasmic HCN1 expression showed no significant change. The distribution of HCN1 in the distal dendrites of neurons decreased. During the epilepsy period, similar HCN1 alterations were observed in the neocortex of rats with cobalt wire-induced epilepsy and hippocampus of rats with lithium pilocarpine-induced epilepsy, including downregulation of mRNA levels, decreased total protein expression, decreased membrane expression, and decreased distal dendrite expression.
Alterations in HCN1 expression and distribution are involved in epileptogenesis beyond their association with seizure occurrence. Similarities in HCN1 alterations observed in epileptogenesis-related tissues from different models suggest a shared pathophysiological pathway in epileptogenesis involving HCN1 dysregulation. Therefore, the upregulation of HCN1 expression in neurons, maintenance of the HCN1 membrane, and distal dendrite distribution in neurons may represent promising disease-modifying strategies in epilepsy.
The alpha rhythm has been a subject of research for the past few decades. Right-left alpha amplitude asymmetry is a common phenomenon. Several explanations have been proposed to explain this asymmetry, including differences in skull thickness. Our research aims to improve our understanding of the relationship between alpha asymmetry and skull thickness as measured by CT/MRI images.
We analyzed EEGs to study alpha rhythm characteristics. Alpha rhythm amplitude was measured using peak-to-peak values in O1 and O2 reference channels. Significant alpha asymmetry was defined as exceeding 20%. Skull thickness differences at corresponding locations were determined through CT/MRI scans. We examined the correlation between alpha and skull thickness asymmetry using Kruskal-Wallis, Spearman correlation, and median regression.
We examined 401 EEGs and images, categorizing patients into three groups based on alpha asymmetry. Group 1(n= 211) had less than 20 percent alpha asymmetry, Group 2(n=107) showed higher right-side alpha amplitudes, and Group 3(n= 83) displayed higher left-side alpha amplitudes. Our analysis revealed a significant association between groups with asymmetry and skull thickness differences (p<0.001), with a Spearman correlation (Rs) of −0.25 (p<0.001), indicating a significant negative correlation. After adjusting for age, sex, and handedness, Median Regression confirmed a statistically significant variation in skull thickness difference among the groups.
The present study involving a large cohort, the first of its kind, demonstrated a significant relationship between alpha amplitude asymmetry and skull thickness.