Drug-resistant Partial Seizures Research Articles

In people with drug-resistant partial seizures, how does high vagus nerve stimulation (VNS) compare with low VNS in improving outcomes?

In people with drug-resistant partial seizures, how does high vagus nerve stimulation (VNS) compare with low VNS in improving outcomes?

Safety and efficacy of cenobamate in patients with uncontrolled focal seizures - a review of the literature

Epilepsy is one of the most common diseases of the nervous system, characterized by the occurrence of recurrent and unprovoked seizures, which are an expression of abnormal brain activity associated with sudden and excessive bioelectric discharges. Partial seizures come from specific areas of the brain. They can run with motor, autonomic, sensory, and psychological symptoms. Currently, new active substances are sought that can be used in the treatment of drug-resistant partial seizures.
 The aim of the study is to evaluate the safety and efficacy of cenobamate in the treatment of patients with uncontrolled, partial seizures. Our study material consisted of publications, which were found in PubMed, Google Scholar, and Embase databases. In order to find the proper publications, the search has been conducted with the use of a combination of keywords like: “cenobamate”, “focal seizures”, “cenobamate in epilepsy”. The first step was to find proper publications from the last 10 years. The second step was to carry out an overview of the found publications.
 Studies have shown that treatment with cenobamate significantly improved seizure control in adults with uncontrolled focal seizures. Long-term use of cenobamate is safe and well-tolerated by patients. Most adverse events are mild or moderate.

SURGICAL AND SEIZURE TREATMENT OUTCOMES IN ADULT DYSEMBRYOPLASTIC NEUROEPITHELIAL TUMORS: A CASE SERIES.

SUMMARYDysembryoplastic neuroepithelial tumors (DNETs) are benign neoplasms classified in the category of glioneuronal tumors. The estimated incidence of DNETs is 0.03 per 100,000 person per year with the age peak in a range between 10 and 14 years, and decreasing dramatically with increasing age. They are seldom diagnosed in persons above 20 years of age, being a cause of tumor-related intractable epilepsy that begins in childhood or adolescence. They have been proven to be the second most common type of epileptogenic tumors in pediatric population. These rare tumors cause chronic drug-resistant partial complex seizures with or without secondary generalization. Herein, we provide institutional case series of six adult patients with temporal lobe DNET presenting with complex partial seizures. Lesionectomy was performed with tumor resection in toto in three patients. In another three, partial resection was performed, whereas tumor remnant was left intact to avoid possible basal ganglia damage. All patients were seizure free postoperatively. Lesionectomy alone in temporal lobe epilepsy was associated with less favorable outcome than anterior temporal lobectomy. Total tumor removal is considered a major prognostic factor in most studies.

Effectiveness and safety of rufinamide at treatment of epilepsy with complications and drug-resistant epilepsy (according to meta-analysis data)

Meta-analysis was undertaken to evaluate rufinamide safety and effectiveness in numerous heterogeneous groups of patients with severe and drug resistant epileptic disorders. There were 164 relevant articles available via medico-clinical periodic databases, but only 15 have been chosen suitable for meta-analysis. All together 1847 participants were included into common massive, with Lennox-Gastaut syndrome (LGS) and similar encephalopathy syndromes, and with drug-resistant partial epileptic forms. 1169 were administered rufinamide additionally to typical anti-epileptic medications (experimental group). 686 received treatment with common practice drugs without rufinamide (control group). Patient with more than 50% seizures reduction were more numerous in rufinamide group (χ2=89.7 with р=0.000...; ОR=2.9 with 95% CI 2.3-3.7). Most frequent and statistically reliable complications of rufinamide use were headache/dizziness and nausea/vomiting. Rufinamide is safe and effective for treatment of different epilepsies including LGS and drug-resistant partial seizures. Rufinamide may be used as second-line adjuvant for routine neurologic practice.

In people with drug-resistant partial seizures, how does vagus nerve stimulation using high stimulation compare with low stimulation at improving outcomes?

In people with drug-resistant partial seizures, how does vagus nerve stimulation using high stimulation compare with low stimulation at improving outcomes?

Efficacy and safety of perampanel in patients with drug-resistant partial seizures after conversion from double-blind placebo to open-label perampanel

To evaluate the efficacy and safety of perampanel in patients with drug-resistant partial seizures after the conversion from double-blind placebo in three phase III studies to open-label perampanel, and to assess the impact of perampanel titration rates through a comparison of weekly vs biweekly dose increases. Patients who completed the three multinational, double-blind, placebo-controlled, phase III core studies (studies 304, 305, or 306) were eligible to enroll in the extension study (study 307). Patients completing the double-blind treatment (6-week titration, 13-week maintenance) with placebo (DB-PBO) or perampanel (DB-PER) began the extension study with a 16-week blinded conversion period, during which DB-PBO patients were switched to perampanel. Doses were titrated in 2-mg increments (biweekly) to an individualized maximum tolerated dose of perampanel (up to 12 mg/day). Patients then entered a planned, open-label treatment period. Perampanel treatment during the extension study reduced total seizure frequency/28 days relative to the double-blind prerandomization baseline regardless of prior perampanel or placebo treatment in the core studies. In the DB-PBO patients, median percent reductions in seizure frequency at the end of the double-blind period, at the end of the conversion period, and at Weeks 40-52 in the open-label maintenance period were 18.6%, 44.3%, and 55.0%, respectively. Seizure control was also improved in the DB-PER patients during the extension period compared to the end of the double-blind period. Responder rates were similar between the 2 patient groups at the end of the conversion period. Perampanel was well tolerated, with the most common treatment-emergent adverse events being dizziness, somnolence, weight increase, irritability, fatigue, and headache. For those patients randomized to the 12 mg group (DB-PER 12 mg), 78.4% reached the daily dose of 10 or 12 mg by the end of the 6-week titration period of the double-blind phase. By the end of the 16-week conversion period of the extension study, 64.0% of DB-PBO patients reached the daily dose of 10 or 12 mg. Seizure frequency reduction was greater after the first 13-week maintenance period of the extension study in the DB-PBO group compared to patients assigned to DB-PER 12mg during the 13-week maintenance period of the double-blind study. Patients who received placebo in the phase III core DB studies and transitioned to perampanel in the open-label extension study (DB-PBO) achieved seizure control at the end of the conversion period similar to that of patients who had been previously exposed to perampanel (DB-PER) as well as comparable safety outcomes. Patients who received perampanel during the core studies and continued with treatment during the extension study (DB-PER) also showed sustained improvements in seizure control with long-term exposure to perampanel.

Vagus nerve stimulation for partial seizures.

Vagus nerve stimulation for partial seizures.

Absence of Liver Toxicity in Perampanel-Treated Subjects: Pooled results from partial seizure phase III perampanel clinical studies

The liver plays a major role in the metabolism and elimination of many antiepileptic drugs (AEDs), including perampanel. Some of the metabolites identified for perampanel are likely formed via reactive intermediates, which have the potential to covalently bind to protein and cause idiosyncratic toxicities, including hepatotoxicity. The approved AED perampanel is a selective, noncompetitive AMPA receptor antagonist. The safety and tolerability of perampanel have been well documented in 3 double-blind, randomized, placebo-controlled, phase III studies. Here we report the effects of perampanel on liver function in patients from the phase III studies to assess the potential for liver toxicity. Following 6-week baseline, patients (≥12 years old) with drug-resistant partial seizures were randomized to once-daily double-blind treatment (6-week titration, 13-week maintenance) with 2, 4, 8, or 12mg perampanel (n=1038) or with placebo (n=442). Clinical laboratory tests for hepatobiliary laboratory parameters were evaluated at baseline and at end of treatment. These included alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, gamma-glutamyl transpeptidase, and total bilirubin. Treatment-emergent markedly abnormal values (an increase in NCI-CTC grade relative to baseline and a grade ≥2) and treatment-emergent adverse events (TEAEs) related to hepatobiliary parameters were also recorded. Mean hepatobiliary values were within normal ranges at baseline and end of treatment for all perampanel groups and placebo. Mean changes from baseline to end of treatment were small. The incidence of markedly abnormal results was very low for perampanel and placebo. TEAEs related to hepatobiliary parameters occurred in 0.4% of perampanel patients and 0% of placebo patients. Hepatobiliary disorders included cholelithiasis (n=3 in perampanel) and abnormal hepatic function (n=1 in perampanel). None of the events were serious or led to perampanel discontinuation. No subject had values that met the criteria for Hy's Law. Hepatobiliary laboratory data and related TEAEs were not notably different between perampanel and placebo treatment groups, and no dose-related trends were observed. Based on the laboratory results from the 3 Phase III studies, perampanel (2, 4, 8, and 12mg) demonstrated no clinically important effects on liver function tests, indicating perampanel is an AED with a low potential for drug-induced liver toxicity.

Progressive dysembryoplastic neuroepithelial tumour

Dysembryoplastic neuroepithelial tumour (DNET) is a benign tumour characterised by cortical location and presentation with drug resistant partial seizures in children. Recently the potential for malignant transformation has been reported, however progression without malignant transformation remains rare. We report a case of clinical and radiologic progression of a DNET in a girl 10years after initial biopsy.

Current role of rufinamide in the treatment of childhood epilepsy: Literature review and treatment guidelines

PurposeThe literature on the efficacy and safety of rufinamide in childhood-onset epilepsy syndromes currently includes approximately 600 paediatric patients. This paper summarizes the views of a panel of experienced European epileptologists with regard to the current role of rufinamide in the treatment of childhood epilepsies. ResultsRufinamide is effective in decreasing the seizure frequency in the Lennox-Gastaut syndrome (LGS), especially tonic and atonic seizures. It might consequently be preferred to other drugs as a second-line treatment for LGS when drop-attacks are frequent. The mean responder rate in the published studies is 38% with seizure freedom achieved in 2.4% of patients. Rufinamide has shown some efficacy in epileptic encephalopathies other than LGS. It can be also effective as adjunctive therapy in children and adolescents with drug-resistant partial seizures. The available data suggest that rufinamide has an acceptable risk/benefit ratio with quite a low risk of aggravating seizures. Common adverse effects (somnolence, nausea and vomiting) are usually mild and self-limiting; they are more frequently observed during titration than in the maintenance phase, suggesting that low escalation rates might be associated with fewer adverse effects. Rufinamide appears to have a favourable cognitive profile compared with other antiepileptic drugs. ConclusionRufinamide is only approved for adjunctive treatment of seizures associated with LGS in children 4 years of age and older. There are very few data on rufinamide treatment at the onset of LGS or early in the course of the disorder; whether early treatment will improve outcome has yet to be determined.

Dysembryoplastic neuroepithelial tumor, a pure glial tumor? Immunohistochemical and morphometric studies

Dysembryoplastic neuroepithelial tumor (DNT) is a benign glioneuronal tumor, occurring in children and adolescents, typically associated with drug-resistant partial seizures. Pathologically, DNT is characterized by a specific glioneuronal element that is comprised of oligodendroglia-like cells (OLC) and floating neurons. The definition of DNT is currently controversial and the incidence of DNT varies among institutions. In this study we characterize the morphologic profiles of OLC and floating neurons by performing immunohistochemical and morphometric studies on seven cases of a simple form of DNT. While a majority of OLC was positive for oligodendrocyte transcription factor 2 (Olig2), only floating neurons and a few small cells were positive for neuronal nuclear antigens (NeuN). Double immunofluorescence studies revealed co-localization of Olig2 and galectin 3 in OLC, but no co-localization of Olig2 and NeuN. The distribution pattern of NeuN-positive nuclei within the tumor tissue was not different from that in the adjacent neural tissue. A section cut perpendicular to the cortex stained with NeuN showed a continuous laminar arrangement with the adjacent cortex. Densities of NeuN-positive nuclei from tumors embedded in the white matter were significantly lower than those from tumors in the gray matter. Our results suggest that the NeuN-positive small and large cells observed within the specific glioneuronal element are in fact entrapped granular and pyramidal cells within the cortex and that OLCs are essentially glial and not neuronal in nature. DNT is thus a pure glial tumor rather than a glioneuronal tumor, that is, the equivalent of non-infiltrating oligodendroglioma, grade I.

Dysembryoplastic neuroepithelial tumors: Epileptogenicity related to histologic subtypes

ObjectiveTo analyze the electroclinical features and the relationship between the epileptogenic zone (EZ), the tumor and focal cortical dysplasia (FCD) in the three histologic subtypes of dysembryoplastic neuroepithelial tumors (DNTs) (“simple”, “complex” and “non-specific forms”). MethodsWe analyzed electroclinical data from 78 patients (50 males; 3–54years) operated for intractable epilepsy due to a DNT. We compared EZ extent, defined by stereo-electroencephalography (n=33), with the tumor and FCD areas, in each DNT subtype. ResultsNon-specific forms (68%) and temporal location were predominant (73%). The main characteristics consisted of late childhood epilepsy onset (median 12years), drug-resistant partial seizures and EEG abnormalities concordant with tumor location. In all DNT subtypes, intrinsic epileptogenicity was demonstrated by intralesional recordings (n=30), displaying a depressed background activity interrupted by rapid spikes or polyspikes. EZ co-localized with the tumor in all simple and complex DNTs, but in only 1/3 of non-specific DNTs. The main discordance between the EZ and tumor extent was found in temporal non-specific DNTs associated with extensive FCD. ConclusionThese results are helpful when planning surgery for DNTs. SignificanceIntrinsic epileptogenicity characterizes all DNTs; however, the EZ differs according to histologic subtypes and is particularly widespread in non-specific temporal forms.

Eslicarbazepine acetate for partial-onset seizures

Eslicarbazepine acetate (ESL), a new voltage-gated sodium channel blocker that is chemically related to carbamazepine and partially metabolized to oxcarbazepine, has attracted attention as results of previous Phase II and III studies demonstrated and confirmed efficacy and tolerability of ESL 800 and 1200 mg once daily as add-on therapy for adult patients with drug-resistant partial-onset seizures. In children, efficacy data point towards a dose-dependent decrease in seizure frequency and tolerability analyses showed a low incidence of mild drug-related adverse effects at 5 and 15 mg/kg/day. The most frequently reported adverse effects were dizziness, somnolence, headache, diplopia, nausea and vomiting. The convenience of once-daily dosing and a short/simple titration regimen in combination with a comparative efficacy and tolerability profile might promote ESL as a valid alternative to the current adjunctive antiepileptic drug therapy armamentarium for drug-resistant partial seizures in adults. Since clinical trials in children and adolescents on ESL efficacy and safety are ongoing and data already published are far from conclusive, the therapeutic value of ESL in this special population has to be established in the near future.

PO.01 IDDM associated with cerebellar ataxia; drug resistant complex partial seizures and intrathecal synthesis of anti GAD-Ab

High levels of antibodies to glutamic acid decarboxylase (anti GAD-Ab) are an uncommon association in neurological conditions. We describe a patient who initially presented with cerebellar ataxia. Four years later...

Eponym

Rasmussen's syndrome (RS) is a rare acquired progressive inflammatory encephalopathy characterized by drug-resistant partial seizures and cognitive deterioration resulting from a gradual impairment and a subsequent atrophy of a single brain hemisphere. It was firstly described by Theodore Rasmussen in 1958. The original etiopathogenic hypothesis of a chronic viral infection no longer holds. Today, the presumed mechanism is a complex autoimmune process comprising an active role of both cytotoxic T lymphocytes and circulating autoantibodies, activating the subunit 3 of the ionotropic glutamate receptor (GluR3Ab). Several medical options, such as antiepileptic drugs and immunomodulatory therapies, deserve consideration to face epileptic manifestations and to slow neurologic regression. Yet, all these therapies turn out to be almost always just temporizing measures. Surgical disconnection of the affected hemisphere ("functional hemispherectomy") is the best therapeutic choice to achieve the arrest of the disease, a good seizure control, the block of neurologic decline, and the improvement of patient's quality of life.

Intractable cryptogenic frontal lobe epilepsy in a patient with MURCS association

ABSTRACT The MURCS association is a rare, nonrandom association of müllerian duct aplasia, renal aplasia and cervicothoracic somite dysplasia. The etiology is unknown. Although it is usually a sporadic disorder, familial cases with uterovaginal anomalies have been reported. Occasionally, it may be accompanied by abnormalities involving various other organs or systems. Malformations related to the central nervous system are very rare and the presence of seizures has not been reported previously. We present a 26‐year‐old female with MURCS association who had late onset, drug resistant partial seizures presumably originating in the frontal lobe.

MRI during postangiography headache

A 34-year-old patient, with no history of migraine, who suffered from drug-resistant partial seizures related to a right frontal cortical dysplasia, underwent a right carotid arteriography as part of presurgical evaluation. After the examination, he …

Vagus nerve stimulation for partial seizures.

Vagus nerve stimulation (VNS) has recently been introduced as an adjunct for treating patients with seizures. The aim of this systematic review was to overview the current evidence for the effects of vagus nerve stimulation, when used as an adjunctive treatment for patients with drug-resistant partial epilepsy. To determine the effects of VNS high-level stimulation compared to low-level (presumed subtherapeutic dose) stimulation. We searched the Cochrane Epilepsy Group trials register, MEDLINE (January 1966 to October 2000) and The Cochrane Controlled Trials Register (Cochrane Library Issue 4, 2000). Randomized, double-blind controlled trials of VNS comparing high and low stimulation paradigms. Studies in adults or children with drug-resistant partial seizures. Two reviewers independently selected trials for inclusion and extracted data. The following outcomes were assessed: (a) 50% or greater reduction in total seizure frequency; (b) treatment withdrawal (any reason); (c) side effects. Primary analyses were intention to treat. Sensitivity best and worst case analyses were also undertaken. Summary odds ratios (ORs) were estimated for each outcome. Results of the overall efficacy analysis show that VNS stimulation using the high stimulation paradigm was significantly better than low stimulation. The overall OR (95% Confidence Interval (CI)) for 50% responders across all studies is 1.93 (1.1,3.3). This effect did not vary substantially and remained statistically significant for both the best and worst case scenarios. Results for the outcome "withdrawal of allocated treatment" suggest that VNS is well tolerated as no significant difference was found between the high and low stimulation groups, and withdrawals were rare. Statistically significant adverse effects associated with implantation (low versus baseline) were hoarseness, cough, pain and paresthesia. Statistically significant adverse effects associated with stimulation (high versus low) were hoarseness and dyspnea, suggesting the implantation is associated with hoarseness, but the stimulation produces additional hoarseness. VNS for partial seizures appears to be an effective and well tolerated treatment. Adverse effects of hoarseness, cough, pain, paresthesias and dyspnea are associated with the treatment but appear to be reasonably well tolerated as dropouts were rare. Typical central nervous system adverse effects of antiepileptic drugs such as ataxia, dizziness, fatigue, nausea and somnolence were not statistically significantly associated with VNS treatment.

Intracerebral evoked potentials in pitch perception reveal a functional asymmetry of the human auditory cortex.

One acoustic feature that plays an important role in pitch perception is frequency. Studies on the processing of frequency in the human and animal brain have shown that the auditory cortex is tonotopically organized: low frequencies are represented laterally whereas high frequencies are represented medially. To date, the study of the functional organization of the human auditory cortex in the processing of frequency has been limited to the use of either scalp-recorded auditory evoked potentials (AEPs), which have relatively poor spatial resolving power, or functional imagery techniques, which have poor temporal resolving power. The present study uses intracerebrally recorded AEPs to explore this topic in the primary and secondary auditory cortices of both hemispheres of the human brain. Recordings were carried out in 45 adult patients with drug-resistant partial seizures. In the right hemisphere, clear spectrally organized tonotopic maps were observed with distinct separations between different frequency-processing regions. AEPs for high frequencies were recorded medially, whereas AEPs for low frequencies were recorded laterally. In the left hemisphere, however, this tonotopic organization was less evident, with different regions involved in the processing of a range of frequencies. The hemisphere-related difference in the processing of tonal frequency is discussed in relation to pitch perception.

Visual impairment in children with epilepsy treated with vigabatrin

Vigabatrin is an anti-epileptic drug particularly useful for drug-resistant partial seizures and infantile spasms. Recently, vigabatrin-induced visual field constriction (VFC) and abnormal ocular electrophysiological studies were reported. In this study, we assessed visual fields, visual evoked potentials (VEPs), and electroretinography (ERG) in children treated with vigabatrin. Twenty-four visually asymptomatic children underwent a clinical ophthalmological examination, perimetry when appropriate, and VEP and ERG. Thirteen patients had at least one abnormal study. VFC was seen in 11 of 17 patients who had perimetry; 5 of 15 patients who underwent VEP testing and 4 of 11 who underwent ERG testing had abnormal examinations. For the most part, abnormal VEPs and ERGs were found in children who also had VFC. There was a consistent trend for longer treatment periods to correlate with VFC, abnormal ERGs, and VEPs. In summary, over half of the children treated with vigabatrin demonstrated VFC or abnormal ocular electrophysiological studies. Perimetry seemed to be the most sensitive modality for identifying vigabatrin toxicity. Abnormal ERGs and VEPs were primarily seen in children with VFC and may be useful in monitoring children who are not appropriate candidates for perimetry. Although the incidence of vigabatrin-induced VFC is worrisome, in the context of intractable seizures or infantile spasms, therapeutic benefits must be weighed against risks.