Drug-resistant Epilepsy Research Articles

Dramatic improvement of drug-resistant epilepsy following cerebral infarction: a case report

BackgroundAn estimated 30% of patients with epilepsy experience drug-resistant epilepsy, which is the failure to control seizures despite the use of two or more antiseizure medications. Although other treatment options are considered, these alternatives often prove ineffective.Case presentationA 60-year-old East Asian male patient diagnosed with drug-resistant epilepsy experienced several seizures daily despite being on eight different antiseizure medications. Seizures began at age 15. He underwent epilepsy surgery at age 34, yet the seizures persisted. An electroencephalogram revealed multifocal sharp waves in the left hemisphere. Cerebral hemorrhages at ages 47, 50, and 56 were caused by head trauma during seizures. The patient became wheelchair-bound and now resides in a nursing home. At age 58, after suffering an acute cerebral infarction due to occlusion of the left internal carotid artery, his daily seizures ceased entirely. Despite remaining wheelchair-bound, he did not experience a significant decline in his quality of life. The cessation of seizures has reduced his risk of further trauma, and he has remained seizure-free for 3 years on just one antiseizure medication.ConclusionSurgical treatments for epilepsy often fail, with insufficient resection being a leading cause of these failures. In some cases, extensive destruction from an ischemic stroke may be beneficial. Furthermore, this case suggests that infarction therapy could be a potential treatment for patients with drug-resistant epilepsy.

First-in-human microelectrode recordings from the vagus nerve during clinical vagus nerve stimulation.

Vagus nerve stimulation (VNS) is an effective treatment for people with drug-resistant epilepsy. However, its mechanisms of action are poorly understood, including which nerve fibers are activated in humans during VNS in typical clinical settings and which are required for clinical efficacy. In particular, there have been no intraneural recordings of vagus nerve fiber activation in awake humans undergoing chronic VNS. In this study, for the first time, we report recordings from the vagus nerve in this setting. The recordings were performed using a sterile tungsten microelectrode inserted percutaneously into the cervical vagus nerve under ultrasound guidance. The clinical VNS systems were used to deliver stimulation while activity in the vagus nerve was recorded. In addition to activating myelinated axons at low currents, we provide evidence that VNS can also activate unmyelinated C fibers in the vagus nerve at currents <1 mA. These results add to our understanding of how VNS exerts its beneficial effects in drug-resistant epilepsy. Here we describe for the first time, electrical recordings from the vagus nerve in awake drug-resistant epilepsy patients with an implanted vagus nerve stimulation (VNS) device. We found that the VNS device was able to activate both myelinated and unmyelinated fibers within the vagus nerve, whichcontributes to our understanding of how VNS works in the context of drug-resistant epilepsy.

Clinical and biochemical assessments of circulating High Mobility Group Box Protein1 in children with epilepsy: relation to cognitive function and drug responsiveness.

Childhood epilepsy is a major health concern posing a significant burden and having disastrous consequences for cognitive function. High Mobility Group Box1 (HMGB1) is an activator of neuroinflammation, and it is possibly involved in the initiation and progression of epilepsy. We aimed to investigate circulating HMGB1 in children with epilepsy and its connection to cognitive function and drug responsiveness. Case-control research included 100 epileptic youngsters and 100 healthy matched controls. Serum HMGB1 was measured using a commercially available ELISA assay. Cognitive functions were evaluated by the Stanford-Binet test 5th edition. Drug-resistant epilepsy (DRE) was found in 37% of the investigated patients. Epileptic children have lower cognitive function parameter levels versus the control group and lower cognitive function in the DRE group compared to the drug-responsive group (P-value < 0.0001). HMGB1 levels were significantly higher in the patients' group (6.279µg/L) compared to the control group (2.093µg/L) and in the drug-resistant group (14.26µg/L) versus the drug-responsive group (4.88µg/L). A significant negative correlation was detected between HMGB1 with Full-scale IQ (r = - 0.547, P = 0.000), Visual-spatial reasoning (r = - 0.501, P = 0.000), fluid reasoning (r = - 0.510, P = 0.000), and working memory (r = - 0.555, P = 0.000). Serum HMGB1 cut-off levels > 6.85µg/L differentiate drug-responsive from resistant patients. Elevated HMGB1 levels, especially in patients with drug-resistant epilepsy, correlate negatively with cognitive performance, emphasizing its importance as a potential marker for early prediction of drug resistance and impairment of cognitive function.

[11C]Metoclopramide PET can detect a seizure-induced up-regulation of cerebral P-glycoprotein in epilepsy patients

BackgroundP-glycoprotein (P-gp) is an efflux transporter which is abundantly expressed at the blood-brain barrier (BBB) and which has been implicated in the pathophysiology of various brain diseases. The radiolabelled antiemetic drug [11C]metoclopramide is a P-gp substrate for positron emission tomography (PET) imaging of P-gp function at the BBB. To assess whether [11C]metoclopramide can detect increased P-gp function in the human brain, we employed drug-resistant temporal lobe epilepsy (TLE) as a model disease with a well characterised, regional P-gp up-regulation at the BBB.MethodsEight patients with drug-resistant (DRE) TLE, 5 seizure-free patients with drug-sensitive (DSE) focal epilepsy, and 15 healthy subjects underwent brain PET imaging with [11C]metoclopramide on a fully-integrated PET/MRI system. Concurrent with PET, arterial blood sampling was performed to generate a metabolite-corrected arterial plasma input function for kinetic modelling. The choroid plexus was outmasked on the PET images to remove signal contamination from the neighbouring hippocampus. Using a brain atlas, 10 temporal lobe sub-regions were defined and analysed with a 1-tissue-2-rate constant compartmental model to estimate the rate constants for radiotracer transfer from plasma to brain (K1) and from brain to plasma (k2), and the total volume of distribution (VT = K1/k2).ResultsDRE patients but not DSE patients showed significantly higher k2 values and a trend towards lower VT values in several temporal lobe sub-regions located ipsilateral to the epileptic focus as compared to healthy subjects (k2: hippocampus: +34%, anterior temporal lobe, medial part: +28%, superior temporal gyrus, posterior part: +21%).Conclusions[11C]Metoclopramide PET can detect a seizure-induced P-gp up-regulation in the epileptic brain. The efflux rate constant k2 seems to be the most sensitive parameter to measure increased P-gp function with [11C]metoclopramide. Our study provides evidence that disease-induced alterations in P-gp expression at the BBB can lead to changes in the distribution of a central nervous system-active drug to the human brain, which could affect the efficacy and/or safety of drugs. [11C]Metoclopramide PET may be used to assess or predict the contribution of increased P-gp function to drug resistance and disease pathophysiology in various brain diseases.Trial registrationEudraCT 2019-003137-42. Registered 28 February 2020.

Metabolic Reprogramming via Ketogenic Diet: A Novel Approach to Combating Neurological Diseases

Epilepsy is a chronic neurological disorder characterized by a persistent tendency for the brain to generate seizures, affecting approximately 0.5–1% of the global population. Despite advances in pharmacological treatments and surgical interventions, around 30% of individuals with epilepsy continue to experience seizures, leading to significant impacts on quality of life. Among these individuals, many suffer from drug-resistant epilepsy (DRE), where seizures persist despite optimal drug therapy or surgical interventions.In recent years, the ketogenic diet (KD)—a high-fat, low-carbohydrate dietary regimen—has emerged as an effective non-pharmacological strategy for managing DRE. The KD works by inducing ketosis, a metabolic state where the body uses fat as the primary energy source instead of carbohydrates, which has been associated with neuroprotective effects and significant seizure reduction. Variants of the KD, such as the Modified Atkins Diet (MAD) and Low Glycemic Index Treatment (LGIT), offer less restrictive alternatives that have shown similar efficacy in reducing seizure frequency.This review explores the cellular and molecular mechanisms of the KD, evaluates its safety and tolerability across different age groups, and assesses its efficacy in treating epilepsy, particularly DRE. The findings underscore the potential of personalized dietary interventions to serve as effective adjunctive therapies in the management of epilepsy, offering new hope for individuals who do not respond to conventional treatments.

Virtual resection evaluation based on sEEG propagation network for drug-resistant epilepsy

Drug-resistant epilepsy with frequent seizures are considered to undergo surgery to become seizure-free, but seizure-free rates have not dramatically improved, partly due to imprecise intervention locations. To address this clinical need, we construct effective connectivity to reveal epilepsy brain dynamics. Based on the propagation path captured by the high order effective connectivity, calculate the control centrality evaluation scheme of the excised area. We used three datasets: simulation dataset, clinical dataset, and public dataset. The epileptogenic propagation network was quantified by calculating high-order effective connection to obtain accurate propagation path, based on this, combined with the outdegree index for virtual resection. By removing electrodes and recalculating control centrality, we quantify each electrode or region’s control centrality to evaluate the virtual resection scheme. Three datasets obtained consistent results. We track the accurate propagation path and find the obvious inflection points occurring during the excision process. The minimum intervention targets were obtained by comparing different schemes without recurrence. The clinical data with multiple seizures found that after resection, the brain reaches a stable state and is less likely to continue spreading. By quantitative analysis of control centrality to evaluate the possible excision scheme, finally we obtain the best intervention area for epilepsy, which assist in developing surgical plans.

Increased cerebellar vermis volume following repetitive transcranial magnetic stimulation in drug-resistant epilepsy: a voxel-based morphometry study

IntroductionVoxel-based morphometry (VBM) was applied to explore structural changes induced by repetitive transcranial magnetic stimulation (rTMS) and the relationship with clinical outcomes. Moreover, the relationship between each segmented regional gray matter (GM) volume was investigated to identify circuits involved in the rTMS treatment process in patients with drug-resistant epilepsy (DRE).MethodsNineteen patients with DRE were finally included in the analysis. A session of rTMS was applied for 5 consecutive days. Participants received either 1,000 or 3,000 pulses, at a frequency of 0.5 Hz and the intensity was set at 90% of the individual’s resting motor threshold. VBM analysis was performed to explore regional GM volume changes 2 months after rTMS application. The regional volume change was correlated with seizure reduction rate. Relationships between changes in GM volume in each anatomically parcellated region were analyzed using a fully-automated segmentation pipeline.ResultsCompared to the baseline, seizure frequency was reduced, and quality of life was improved after rTMS treatment. Regional volume was increased in the cerebellar vermis 2 months after rTMS application. The increased cerebellar vermis volume correlated with the reduced seizure frequency. Regional volume changes in the cerebellar vermis were correlated with changes in the subcortical and cortical GM regions including the thalamus, caudate, and frontal cortex.DiscussionThese results indicate that rTMS treatment effectively reduced seizure frequency in patients with DRE. Increased volume in the cerebellar vermis and activations of the cerebello-thalamo-cortical circuit may be a crucial mechanism underlying the effectiveness of rTMS application in patients with DRE.

Associations Between Testing and Treatment Pathways in a Case of Pediatric Nonlesional Epilepsy: A Census Survey of NAEC Center Directors.

Epilepsy surgery is vital in managing of children with drug-resistant epilepsy. Noninvasive and invasive testing modalities allow for evaluation and treatment of children with drug-resistant epilepsy. Evidence-based algorithms for this process do not exist. This study examines expert response to a vignette of pediatric nonlesional epilepsy to assess associations in evaluation and treatment choices. We analyzed annual report data and an epilepsy practice survey reported in 2020 from 135 pediatric epilepsy center directors in the United States. Characteristics of centers along with noninvasive and invasive testing and surgical treatment strategies were collected. Multivariable logistic regression modeling was performed. The response rate was 100% with 135 responses included in the analyses. Most used noninvasive testing modalities included Neuropsychology evaluation (90%), interictal brain fluorodeoxyglucose-positron emission tomography (85%), and functional magnetic resonance imaging (MRI) (72%) with nearly half obtaining genetic testing. Choosing functional MRI was associated with stereo electroencephalography (EEG) (P = .025) and selecting Wada with subdural grid/strips (P = .038). Directors from pediatric-only centers were more likely to choose stereo EEG as opposed to combined centers (P = .042). Laser interstitial thermal therapy was almost 7 times as likely to be chosen as a treatment modality compared with open resection in dedicated pediatric centers (OR 6.96, P = .002). In a vignette of nonlesional childhood drug-resistant epilepsy, epilepsy center directors' patterns of noninvasive testing, invasive testing, and treatment were examined. Management choices were associated with pediatric versus combined pediatric/adult center characteristics. Expert opinions demonstrated equipoise in evaluation and management of children with drug-resistant epilepsy and the need for evidence-based management strategies.

Multimodal and quantitative analysis of the epileptogenic zone network in the pre-surgical evaluation of drug-resistant focal epilepsy

Surgical resection for epilepsy often fails due to incomplete Epileptogenic Zone Network (EZN) localization from scalp electroencephalography (EEG), stereo-EEG (SEEG), and Magnetic Resonance Imaging (MRI). Subjective interpretation based on interictal, or ictal recordings limits conventional EZN localization. This study employs multimodal analysis using high-density-EEG (HDEEG), Magnetoencephalography (MEG), functional-MRI (fMRI), and SEEG to overcome these limitations in a patient with drug-resistant MRI-negative focal epilepsy. A 17-year-old with drug-resistant epilepsy underwent evaluation. HDEEG, MEG, fMRI, and SEEG were used, with a novel HDEEG-cap facilitating simultaneous EEG-MEG and EEG-fMRI recordings. Electrical and magnetic source imaging were performed, and fMRI data were analysed for homogenous regions. SEEG analysis involved spike detection, spike timing analysis, ictal fast activity quantification, and Granger-based connectivity analysis. Non-invasive sessions revealed consistent interictal source imaging results identifying the EZN in the right anterior cingulate cortex. EEG-fMRI highlighted broader activation in the right cingulate cortex. SEEG analysis localized spikes and fast activity in the right anterior and posterior cingulate gyri. Multi-modal analysis suggested the EZN in the right frontal lobe, primarily involving the anterior and mid-cingulate cortices. Multi-modal non-invasive analyses can optimise SEEG implantation and surgical decision-making. Invasive analyses corroborated non-invasive findings, emphasising the importance of individual-case quantitative analysis across modalities in complex epilepsy cases.

Пути оптимизации антропометрических параметров у детей с фармакорезистентной эпилепсией, получающих кетогенную диетотерапию

Ketogenic diet (KD) whilst being an effective method of diet therapy for drug-resistant epilepsy (DRE) is nevertheless accompanied by a significant number of side effects that include the possibility for the delayed physical development in pediatric patients. The problem is multifactorial and is primarily associated with the non-physiological nature of the ketogenic diet itself. Foreign studies on the KD effect on the physical development in children are contradictory and there are none domestic ones. The purpose of this research was to study the dynamics of anthropometric parameters in children with DRE against the background of KD and to assess the possibilities of the alimentary factor in its improvement. Materials and methods used: single-center retrospective cohort study had been carried out on the basis of the Russian Federal Research Centre for Nutrition, Biotechnology and Food Safety (Moscow, Russia) in 2016-2024. The study included patients with an established diagnosis of DRE against the background of KD aged 1 to 18 y/o. Patients were monitored for 24 months as follows: quarterly during the first year and semiannually during the second year of observation, using anthropometric, clinical-laboratory and clinical-instrumental research methods. Results: by the 3rd month of KD, out of 174 pediatric patients, the diet was effective in 105 (60%); by 12th month, 100% control over attacks was achieved in 11 (6%). Analysis of anthropometric parameters made it possible to establish that at the initial point of observation, in accordance with the z-score of the body mass index (BMI), 108 (64%) had normal nutritional status, 22 (13%) had malnutrition and 40 (24%) were overweight/obese. When studying the dynamics of weight and height indicators of children who were on KD throughout the observation period, it was found that the median BMI z-score statistically significantly changed upward (p=0.047), which was largely due to growth retardation, with a decrease in the height/age z-score throughout the observation period (p&lt;0.001). It was found that the protein component of the diet, as well as the level of ketonemia, have a significant impact on the dynamics of the BMI z-score in KD patients. The amount of protein in the diet at 6% to 7% of the energy value contributed to the maintenance of optimal growth parameters in children within this research. Conclusion: the significance of the BMI indicator in assessing the nutritional status over KD decreases against the background of growth retardation. Taking into account the value of the protein/energy indicator when calculating nutrition helps in maintaining of the physical development rate in such patients.

Chemogenetics with PSAM4-GlyR decreases excitability and epileptiform activity in epileptic hippocampus.

Despite the availability of new drugs on the clinics in recent years, drug-resistant epilepsy remains an unresolved challenge for healthcare, and one-third of epilepsy patients remain refractory to anti-seizure medications. Gene therapy in experimental models has emerged as effective treatment targeting specific neuronal populations in the epileptogenic focus. When combined with an external chemical activator using chemogenetics, it also becomes an "on-demand" treatment. Here, we evaluate a targeted and specific chemogenetic therapy, the PSAM/PSEM system, which holds promise as a potential candidate for clinical application in treating drug-resistant epilepsy. We show that the inert ligand uPSEM817, which selectively activates the chloride-permeable channel PSAM4-GlyR, effectively reduces the number of depolarization-induced action potentials in vitro. This effect is likely due to the shunting of depolarizing currents, as evidenced by decreased membrane resistance in these cells. In organotypic slices, uPSEM817 decreased the number of bursts and peak amplitude of events of spontaneous epileptiform activity. Although administration of uPSEM817 in vivo did not significantly alter electrographic seizures in a male mouse model of temporal lobe epilepsy, it did demonstrate a strong trend toward reducing the frequency of interictal epileptiform discharges. These findings indicate that PSAM4-GlyR-based chemogenetics holds potential as an anti-seizure strategy, although further refinement is necessary to enhance its efficacy.

Case report: Adult patient with WWOX developmental and epileptic encephalopathy: 40 years of observation

WWOX developmental and epileptic encephalopathy is characterised by drug-resistant epilepsy with onset within the first year of life and severe psychomotor developmental delay. This report presents for the first time a clinical case of an adult patient with a homozygous likely pathogenic variant (p.Thr12Met) in the WWOX gene, with more than 40 years of follow-up. The patient had refractory epilepsy with various types of seizures during his life: mainly epileptic spasms, autonomic, myoclonic, tonic seizures, and absences. The patient had a prominent developmental delay with a lack of expressive speech, but by the age of 3, he had acquired the skills to sit, crawl, and walk with support. In adolescence, there was an acute regression of acquired skills to a total absence of independent motor activity. The patient had dysmorphic features, such as upslanting palpebral fissures, arched eyebrows, and hypertelorism. For many years, the patient was given a diagnosis of cerebral palsy; 38 years after the onset of the disease, he was given a molecular genetic diagnosis of WWOX-associated developmental and epileptic encephalopathy. Our observation illustrates the natural history of WWOX-DEE and the high clinical significance of early genetic diagnostics for identifying the cause of developmental delay and resistant epilepsy.

Multi-disciplinary team approach for pediatric hemimegalencephaly: Insights from a single institutional case series.

Recent genetic studies have revealed that hemimegalencephaly (HME) is a multi-system disorder associated with germline or mosaic variants within the PI3K-mTOR-GATOR1 signaling pathways. Patients with HME typically develop drug-resistant epilepsy necessitating extensive evaluation, hemispherectomy, and long-term management. We describe the role of a multidisciplinary team (MDT) for the diagnosis and management of recent patients with HME at UCLA who underwent hemispherectomy. Genetic evaluation identified nine patients with the following variants: NPRL3 x2 germline, PIK3CA mosaicism x4, MTOR mosaicism x1, AKT3 mosaicism x1, unknown x1. Each patient's MDT comprised 4-9 specialties. One child with a MTOR variant had persistent epilepsy after hemispherectomy, but addition of everolimus resulted in an 80% decrease in seizure frequency. Another child with hemihypertrophy and PIK3CA mosaic variant was offered targeted PIK3CA inhibitor treatment, alpelisib, for overgrowth. A third child with germline NPRL3 variant inherited from their unaffected mother resulted in a sibling being diagnosed with the variant who later developed seizures secondary to focal cortical dysplasia. The implementation of a MDT offers essential guidance for families affected by HME, encompassing prognostication, surveillance, and therapeutic strategies. Identifying the etiology of HME can facilitate the development of targeted treatments and enable timely genetic counseling. PLAIN LANGUAGE SUMMARY: Hemimegalencephaly (HME) is a complex brain disorder caused by genetic changes. It often leads to severe epilepsy that doesn't respond to standard treatments and frequently requires surgery. In this case series, nine patients with HME were identified and found to have genetic mutations in key growth-regulating genes. A multidisciplinary team model was developed to facilitate patients' care. For example, one patient's seizures improved with surgery, another with a new targeted medication, and another received treatment for symptoms of overgrowth. This team approach provides comprehensive care for patients and can lead to efficient care coordination and implementation of novel therapies.

Bilateral pulvinar responsive neurostimulation for bilateral multifocal posteriorly dominant drug resistant epilepsy.

To describe four cases of Responsive Neurostimulation (RNS) in the bilateral pulvinar nuclei (PUL) in individuals with drug resistant epilepsy (DRE). This will show that due to widespread PUL connectivity, bilateral PUL RNS may be an option for some individuals with bilateral multifocal epilepsy. This study comprises two centers' experience with bilateral PUL RNS for DRE. Patients treated with bilateral PUL RNS at Westchester Medical Center (Valhalla, NY) and Corewell Health (Grand Rapids, MI) between the years 2019 and 2022 were analyzed and described. Presented here are methods for target selection, device programming, and clinical outcomes. Two patients with Lennox-Gastaut phenotype (aged 13 and 21 years) with posteriorly dominant discharges were implanted with bilateral PUL electrodes. Additionally, two patients (aged 20 and 31 years) with independent left and right occipital bilateral multifocal seizure onsets were implanted with bilateral RNS devices targeting the ipsilateral PUL and ipsilateral occipital cortex. Subclinical and clinical seizures were captured by RNS electrocorticography (ECoG) in all patients. RNS implantation and treatment was well-tolerated without adverse effects in all patients. Relative to baseline, two patients had 25% and 50% reduction in disabling seizures, and two patients had 71% and 100% reduction in disabling seizures. Stimulation paradigms utilized high frequency stimulation in both Lennox-Gastaut phenotype patients. Low frequency (individualized to the terminal ictal frequencies) stimulation was effective in the two bioccipital patients. RNS with electrode placement targeting bilateral PUL is safe, and no adverse effects have been attributable to the pulvinar electrode placement. PUL responsive neurostimulation is potentially effective for patients with bilateral multifocal, posteriorly dominant DRE. Both high and low frequency responsive stimulation are treatment options. Longer follow-up will shed light on the ultimate reduction of seizure burden. We describe four cases where stimulation devices were placed in the Pulvinar area of the thalamus (central sensory area in the brain). This is very unique and different location than where these devices are typically placed. These patients all had great outcomes with marked seizure reduction, demonstrating that this placement is both safe and effective.

Effects of vagal nerve stimulation parameters on heart rate variability in epilepsy patients

IntroductionVagal nerve stimulation (VNS) is used as an alternative treatment in drug-resistant epilepsy patients. Effects of VNS on the cardiac autonomic system are controversial. In this study, we aimed to investigate the relationship between VNS parameters and heart rate variability (HRV) in epilepsy patients who underwent VNS treatment.MethodsOur study included 31 patients who underwent VNS for drug-resistant epilepsy. Patients were divided into groups according to response to VNS and VNS parameters. All patients underwent 24-h Holter ECG.ResultsThe mean age of 31 VNS-treated epilepsy patients included in the study was 33.87 ± 7.6 years. When patients were grouped according to VNS response, 25 patients were in the VNS responder group and six patients were in the VNS-nonresponder group. When comparing Holter parameters in the VNS responder and non-responder groups, the median HF was significantly lower in the VNS responder group. VNS duration and signal frequency had a positive effect on LF/HF, while output and off time had a negative effect on LF/HF. When ROC analysis was performed to determine the cut-off values of the parameters for the VNS-responsive state, the AUC value of the HF parameter was 0.780, which was statistically significant. The cut-off value to distinguish response to VNS was 156.9.ConclusionIn conclusion, the effects of VNS parameters on HRV parameters are quite complex. However, the conclusion is that VNS is a neuromodulation method that affects the autonomic system in a complex way. Different levels of VNS parameters may also contribute to this effect. Furthermore, HRV parameters can be used as biomarkers to predict the patient population that may benefit from VNS.

Drug-resistant epilepsy cases in chromosomal pathology

Two cases of epilepsy in patients with a rare hereditary pathology associated with a chromosomal mutation caused deletion of chromosome 14 are presented. In the first case, this pathology was manifested in the child by generalized tonic-clonic seizures, delayed psycho-verbal development, and facial skull microanomaly. In the second case, it was expressed in tonic epileptic seizures, delayed psycho-verbal development, developmental microanomalies, pyramidal atactic syndrome and hand joint hypermobility. Such clinical observations are of professional and scientific interest, as they relate to a rare neurological pathology, with drug-resistant epilepsy as a leading sign.

TRANscranial direct current stimulation for FOcal Refractory epilepsy in mitochondrial disease (TRANSFORM): delayed-start, randomised, double-blinded, placebo-controlled study

BackgroundFocal epilepsy is common in children and adults with mitochondrial disease. Seizures are often refractory to pharmacological treatment and, in this patient group, frequently evolve to refractory focal status epilepticus (also known as epilepsia partialis continua). Where this occurs, the long-term prognosis is poor. Transcranial DC stimulation (tDCS) is a promising, non-invasive, adjunctive treatment alternative to common surgical procedures. Limited recruitment of study participants with this rare disease and the ethical challenges of administering a treatment to one group and not another, while maintaining strict methodological rigour can pose challenges to the design of a clinical study.MethodWe designed the first delayed start, double-blinded, sham-controlled study to evaluate the efficacy of tDCS as an adjunctive treatment for focal epilepsy. We will include participants with a genetically confirmed diagnosis of mitochondrial disease with drug-resistant focal epilepsy aged ≥ 2 years, aiming to collect 30 episodes of focal status epilepticus, each treated for a maximum period of 14 days. The early start intervention arm will receive tDCS from day 1. The delayed start intervention arm will receive sham stimulation until crossover on day 3. Our primary endpoint is a greater than 50% reduction from baseline (on day 0) in seizure frequency assessed by 3x daily reporting, accelerometery, and video monitoring. Changes in the underlying epileptogenic focus within the brain related to the tDCS intervention will be assessed by magnetic resonance imaging (MRI) and/or electroencephalography (EEG).DiscussionStudy results in favour of treatment efficacy would support development of tDCS into a mainstream treatment option for focal epileptic seizures related to mitochondrial disease.Trials registrationISRCTN: 18,241,112; registered on 16/11/2021.

Results of surgical treatment for drug-resistant temporal epilepsy and related predictors of negative post-surgery outcome

Objective: to evaluate the results of surgical treatment and identify related predictors of unfavorable outcome in patients with temporal drug-resistant epilepsy (DRE) in long-term postoperative period.Material and methods. Fifty-one patients with temporal lobe DRE were examined using clinical, neuroimaging, electro- physiological, and laboratory research methods from June 2020 to June 2023. Anteromedial temporal lobectomy (AMLE) and selective amygdalohippocampectomy (SAHE) were performed in 38 (74.5%) and 13 (25.5%) cases, respectively. Postsurgery outcomes were evaluated in 51 patients 6 months later, continued in 43 and 20 patients 1 year and 2 years, respectively, afterwards.Results. The percentage of patients with significant improvement (Engel I/II) 6 months, 1 year and 2 years post-surgery was 82.4%, 72.1%, and 55.0%, respectively. After AMLE vs. SAHE, patients had a more favorable outcome while assessing seizure control. The predictors of unfavorable post-surgery outcome included a prolonged epilepsy course before surgery, the presence of electroencephalography-verified epileptiform activity in postoperative period, and repeated surgical intervention. Patient age, the presence of focal seizures evolving into bilateral tonic-clonic seizures as well as more frequent seizures before surgery were considered as potential predictors.Conclusion. The study results show that quite high effectiveness of seizure control in postoperative period in temporal DRE is quite high that may be accounted for by probability of removing epileptogenic foci and suppression of the mechanisms ensuring emergence and irritation of epileptic discharges. Nevertheless, effectiveness of surgical treatment fades off with time, which requires to further investigate the negative factors countering long-term post-surgery effect. In connection with this, a special attention should be paid to factors such as the presence of electroencephalography-verified epileptiform activity in postoperative period, repeated surgical intervention as well as prolonged epilepsy before surgery.

Recent Advances in Pharmacologic Treatments of Drug-Resistant Epilepsy: Breakthrough in Sight.

Epilepsy affects approximately 1% of the world population. Patients have recurrent seizures, increased physical and psychiatric comorbidities, and higher mortality rate than the general population. Over the last 40 years, research has resulted in 20 new antiseizure medications (ASMs) approved between 1990 and 2018. In spite of this, up to one-third of patients (~ 1 million patients in the USA) have drug-resistant epilepsy (DRE), with little change between 1982 and 2018, a period of intense new ASM development. A minority of patients with DRE may benefit from surgical treatment, but this specialized care remains challenging to scale. Therefore, the greatest hope for breakthroughs for patients with DRE is in pharmacologic therapies.Recently, several advances promise to change the outcomes for patients with DRE. Cenobamate, a drug with dual mechanisms of modulating sodium channel currents and GABA-A receptors, achieves 90-100% seizure reduction in 25-33% of patients with focal DRE, a response not observed with other ASMs. Fenfluramine, a serotonin-acting drug, dramatically reduces the frequency ofconvulsive seizuresin Dravet syndrome, a devastating developmental epileptic encephalopathy with severe DRE.Both drugs reduce mortality.In addition, the possibility of DRE prevention was recently raised in patients with tuberous sclerosis complex, a relatively common genetic form of epilepsy. A paradigm shift is emerging in the treatment of epilepsy. Seizure freedom has become attainable in a significant proportion of patients with focal DRE, and dramatic seizure reduction has been achieved in a developmental encephalopathy. Coupled with a rich pipeline of new compounds under clinical development, the long sought-after breakthrough in the treatment of epilepsy may finally be in sight.

Hippocampal microscopic fractional anisotropy is reduced in temporal lobe epilepsy

Abstract Surgical resection is the method of choice for treating drug-resistant focal temporal lobe epilepsy (TLE). Postsurgical outcomes are better when magnetic resonance imaging (MRI) findings can localize the seizure focus for resection. However, many patients are MR-negative, meaning the focus cannot be differentiated from normal tissue in relaxation-weighted MRI. Diffusion MRI shows promise as a preoperative marker of neuronal abnormalities due to its sensitivity to cellular changes such as axon damage, indexed by fractional anisotropy. Microscopic fractional anisotropy is a recently introduced diffusion MRI metric that is sensitive to axon integrity regardless of axon orientation in both grey and white matter. In contrast, regular fractional anisotropy is only sensitive to axon integrity in coherently oriented bundles of fibers. This work investigated whether microscopic fractional anisotropy is sensitive to hippocampal abnormalities in drug-resistant TLE. Diffusion MRI was performed on a 3T scanner in 19 patients (age = 31±10 years) with drug-resistant TLE (of which 10 were MR-negative) and 18 healthy volunteers (age = 38±15). A deep-learning method was employed to segment the hippocampus into smaller subregions corresponding to the subiculum, cornu ammonis (CA) 1, CA2/3, and CA4 plus dentate gyrus (DG). Mean measurements of subregion volume, diffusivity, fractional anisotropy, and microscopic fractional anisotropy were compared between cohorts. In a subset of the TLE cohort suspected to have unilateral pathology (n=15, age = 32±10 years), the percentage differences between measurements ipsilateral and contralateral to the epileptogenic zone were evaluated to assess asymmetry. Microscopic fractional anisotropy was reduced in the hippocampus of drug-resistant TLE patients relative to healthy volunteers. In subregion-specific analysis, microscopic fractional anisotropy was significantly reduced in only the CA4/DG region in patients compared to healthy volunteers, after corrections for multiple comparisons. In the 15 patients with suspected unilateral pathology, microscopic fractional anisotropy was reliably and statistically lower in the ipsilateral CA4/DG region compared to the contralateral side. Significant differences were not observed between TLE patients and healthy volunteers, or between hemispheres for patients with suspected unilateral pathology, for the fractional anisotropy or volume metrics. Diffusion MRI may complement standard imaging procedures by detecting abnormalities in MRI-negative patients. Due to its ability to detect abnormality regardless of axon orientation, microscopic fractional anisotropy may improve seizure focus localization in surgical candidates.