Greater Reduction In Seizure Frequency Research Articles

A nomogram to predict the treatment benefit of perampanel in drug-resistant epilepsy patients

ObjectiveThe objective of this study was to identify the factors that affect the efficacy of added perampanel for the treatment of drug-resistant epilepsy (DRE), and to develop a reliable nomogram to predict the benefit of this addition.MethodsA retrospective clinical analysis was conducted on DRE patients who received perampanel treatment and who were followed up for at least 6 months from January 2020 and September 2023 at the Epilepsy Center of Fujian Medical University Union Hospital. Data from January 2020 to December 2021 were used as development dataset to build model, while the data from January 2022 to September 2023 were used as validation dataset for internal validation. The predictive factors that affected the efficacy of perampanel as DRE treatment were included in the final multivariate logistic regression model, and a derived nomogram was established.ResultsA total of 119 DRE patients who received perampanel treatment were included in this study (development datasets: n = 76; validation data: n = 43). Among them, 72.3% (n = 86) showed a 50% or greater reduction in seizure frequency after perampanel treatment. Of all the parameters of interest, sex, age, history of generalized tonic-clonic seizures, and the number of antiseizure medications were identified as significant predictors for estimating the benefit of adding perampanel for the treatment of DRE. A model incorporating these four variables was developed, and a nomogram was constructed to calculate the probability of benefit of adding perampanel using the model coefficients. The C-index of the predictive model was 0.838, and the validation C-index was 0.756. The goodness-of-fit test showed good calibration of the model (p = 0.920, 0.752 respectively).ConclusionThe proposed nomogram has significant clinical potential for predicting the probability of benefit of perampanel as DRE treatment. This nomogram can be used to identify DRE patients who could benefit from the early addition of perampanel to their treatment regimen.

Modified Atkins diet for drug-resistant epilepsy: A systematic review and meta-analysis of randomized controlled trials.

To evaluate the effectiveness and side-effect profile of the modified Atkins diet (MAD) compared to the usual diet (UD) in reducing seizure frequency among patients with drug-resistant epilepsy (DRE). In February 2023, we conducted an extensive search in PubMed, EMBASE, and Cochrane databases to find randomized controlled trials (RCTs) comparing MAD to UD in patients with drug-resistant epilepsy (DRE) on standard anti-seizure medication (ASM). We used random-effects meta-analyses and the Risk of Bias 2 tool to evaluate treatment effects and assess the quality of the included RCTs, respectively. Six studies were evaluated in the meta-analysis, including 575 patients, of whom 288 (50.1%) were randomized to the MAD. Average follow-up period was 12 weeks. MAD plus standard drug therapy was associated with a higher rate of 50% or greater reduction in seizure frequency compared to UD plus drug therapy (RR 6.28; 95% CI 3.52-10.50; p<0.001), both in children (RR 6.28; 95% CI 3.43-11.49; p<0.001) and adults with DRE (RR 6.14; 95% CI 1.15-32.66; p=0.033). MAD was also associated with a higher seizure freedom rate compared to UD (RR 5.94; 95% CI 1.93-18.31; p=0.002). Five studies reported adverse events with MAD; constipation was reported in 17% of patients (95% CI 5-44%), lethargy in 11% (95% CI 4-25%), and anorexia in 12% (95% CI 8-19%). Due to limited information about the ASM regimens, we were unable to further analyze the interaction between MAD and ASM. This meta-analysis, comprising 575 patients from 6 RCTs, revealed that MAD led to higher rates of seizure freedom and underscored its role in seizure frequency reduction by 50% or more in both adults and children, with no significant adverse events concerns.

Efficacy and Safety of Fenfluramine in Lennox-Gastaut Syndrome: A Systematic Review (P13-1.007)

<h3>Objective:</h3> This systematic review aims to explore the efficacy, safety, and tolerability of fenfluramine for seizure control in patients with Lennox-Gastaut syndrome (LGS). <h3>Background:</h3> Fenfluramine has been recently approved as an adjunctive medication for seizure control in patients with Lennox-Gastaut syndrome (LGS). Previously, it has been used in treatment of patients with Dravet syndrome. <h3>Design/Methods:</h3> We conducted a systematic literature search on MEDLINE, Cochrane, and EMBASE as per guidelines of Preferred Reporting Items for Systematic Reviews (PRISMA). Two clinical trials analysing the effects of different doses of fenfluramine were included in this review. <h3>Results:</h3> In a double-blind phase 3 randomised control trial (RCT), participants were randomised to receive fenfluramine (0.2 or 0.7mg/kg/d) or a placebo. In another open-label clinical trial (Lagae et al.), patients were administered fenfluramine with median dose being 0.4mg/kg/d. 50% or greater reduction in seizure frequency was assessed in both trials. The responder rate in the open-label trial was 62% at 20 weeks and 66.7% at 15 months, while responder rate in the RCT was also significant in both groups (28% in the 0.2mg/kg/day group and 25% in the 0.7mg/kg/day). The median percentage reduction in seizure frequency in the open-label trial was 53% in core and 58% in extension period, while 14.2% reduction in 0.2mg/kg/d and 26.5% reduction in 0.7mg/kg/d were reported in the RCT. Adverse effects were reported in 70% of patients in the open-label trial while the RCT reported ≥1 adverse effects in 78%, 90% and 75% of the participants from 0.2mg/kg/d, 0.7mg/kg/d and placebo groups, respectively. Adverse effects commonly seen were decreased appetite, somnolence, and fatigue. <h3>Conclusions:</h3> Adjunctive use of fenfluramine results in significant improvement in LGS patients refractory to standardised anti-seizure therapies. The side effects reported are usually mild. <b>Disclosure:</b> Mr. Qureshi has nothing to disclose. Ms. Kareem has nothing to disclose. Miss Mehdi has nothing to disclose. Miss Nadeem has nothing to disclose. Miss Majid has nothing to disclose. Dr. Hassan has nothing to disclose. Bakhtawar Ahmad has nothing to disclose. Mr. Aemaz Ur Rehman has nothing to disclose. Dr. Iftikhar has nothing to disclose. Dr. Khokhar has nothing to disclose.

Thalamic neuromodulation outcomes in drug-resistant refractory epilepsy with Deep Brain Stimulation and Responsive Neurostimulation (P5-1.003)

<h3>Objective:</h3> We aim to compare effects of thalamic Deep Brain Stimulator (DBS) and responsive neurostimulator (RNS) device therapy on seizure burden in drug-resistant epilepsy patients. <h3>Background:</h3> Intractable epilepsy unamenable to cortical resection is often treated with a device, either RNS or DBS provides intracranial stimulation. The devices are thought to reduce seizure frequency by reducing synchronization of cortical activity. The RNS provides more localized stimulation while the DBS does this by stimulating the anterior nucleus of the thalamus. At our institution a small number of patients have also undergone thalamic stimulation by using the RNS. <h3>Design/Methods:</h3> We performed retrospective analysis on seizure frequency pre-implant and at most recent follow-up for our cohort, 12 DBS and 6 RNS patients. <h3>Results:</h3> Average age of RNS implantation was 30 years (range 19–41) vs 42 years (range 18–66) for DBS. Thirteen (9 DBS, 4 RNS) of the 18 patients had stereo-EEG (SEEG) evaluation before device placement, SEEG ictal onset was broad or multifocal in all (DBS: 7 – bilateral and 2 – unilateral, RNS: 3 bilateral, 1 unilateral). Three out of five patients who did not have invasive EEG evaluation before device placement had suspected (2) or confirmed (1) genetic etiology, all five had non-localizing, non-lateralizing scalp ictal EEG. The electrodes were placed to the anterior nucleus of thalamus bilaterally in all DBS and four RNS patients, two RNS patients had centromedian nucleus of thalamus sampling. Twelve of our 18 patients (8 out of 12 DBS and 4 out of 6 RNS) were shown to be responders, achieving 50% or greater reduction in seizure frequency. The average follow-up duration for RNS was 22 months (range 3–36), for DBS 13.5 months (range 2–29). <h3>Conclusions:</h3> This analysis demonstrates the potency of thalamic neuromodulation, both RNS and DBS, as therapies capable of seizure relief in wide breadths of epilepsy presentations. <b>Disclosure:</b> Dr. Das has received personal compensation for serving as an employee of Concentra. Dr. Das has received personal compensation in the range of $5,000-$9,999 for serving as an Expert Witness for janicek. The institution of an immediate family member of Dr. Das has received research support from NIH. irina podkorytova has nothing to disclose. Chijindu Iheanacho has nothing to disclose. Dr. Alick-Lindstrom has nothing to disclose. Dr. Agostini has nothing to disclose. Dr. Doyle has nothing to disclose. The institution of Dr. Ding has received research support from National Institute of Aging. The institution of Dr. Ding has received research support from NINDS. Dr. Hays has nothing to disclose. Dr. Perven has nothing to disclose. Dr. Dieppa has nothing to disclose. Dr. Zepeda Garcia has nothing to disclose.

Stiripentol add-on therapy for drug-resistant focal epilepsy.

This is an updated version of the Cochrane Review first published in 2014 and last updated in 2020. For nearly 30% of people with epilepsy, current treatments do not control seizures. Stiripentol is an antiepileptic drug (AED) that was developed in France and was approved by the European Medicines Agency (EMA) in 2007 as an adjunctive therapy with valproate and clobazam for the treatment of Dravet syndrome. To evaluate the efficacy and tolerability of stiripentol as add-on treatment for people with drug-resistant focal epilepsy who are taking AEDs. For the latest update, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE on 28 March 2022. We contacted the manufacturer of stiripentol and epilepsy experts to identify published, unpublished and ongoing trials. Randomised controlled trials of add-on stiripentol in people with drug-resistant focal epilepsy. Review authors independently selected trials for inclusion and extracted data. We investigated outcomes including 50% or greater reduction in seizure frequency, seizure freedom, adverse effects, treatment withdrawal and changes in quality of life. On the basis of our selection criteria, we included no new studies in the present review update. We included only one study from the original review (32 children with focal epilepsy). This study adopted a responder-enriched design and found no clear evidence of a reduction of 50% or more in seizure frequency (risk ratio (RR) 1.51, 95% confidence interval (CI) 0.81 to 2.82; low-certainty evidence) and no clear evidence of seizure freedom (RR 1.18, 95% CI 0.31 to 4.43; low-certainty evidence) when comparing add-on stiripentol with placebo. Stiripentol led to a greater risk of adverse effects considered as a whole (RR 2.65, 95% CI 1.08 to 6.47; low-certainty evidence). When we considered specific adverse effects, CIs were very wide and showed the possibility of substantial increases and small reductions in risks of neurological adverse effects (RR 2.65, 95% CI 0.88 to 8.01; low-certainty evidence). Researchers noted no clear reduction in the risk of study withdrawal (RR 0.66, 95% CI 0.30 to 1.47; low-certainty evidence), which was high in both groups (53.3% in placebo group and 35.3% in stiripentol group; low-certainty evidence). The external validity of this study was limited because only responders to stiripentol (i.e. participants experiencing a decrease in seizure frequency of 50% or greater during an open prerandomisation phase compared with baseline) were included in the randomised, add-on, placebo-controlled, double-blind phase. Furthermore, carry-over and withdrawal effects probably influenced outcomes related to seizure frequency. Very limited information derived from the only included study shows that adverse effects considered as a whole may occur more often with add-on stiripentol than with add-on placebo. We have found no new studies since the last version of this review was published. Hence, we have made no changes to the conclusions as presented in previous versions. We can draw no conclusions to support the use of stiripentol as add-on treatment for drug-resistant focal epilepsy. Additional large, randomised, well-conducted trials are needed.

Felbamate add-on therapy for drug-resistant focal epilepsy.

This is an updated version of the Cochrane Review first published in 2011, and most recently updated in 2019. Epilepsy is a chronic and disabling neurological disorder, affecting approximately 1% of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available antiepileptic drugs and require treatment with multiple antiepileptic drugs in combination. Felbamate is a second-generation antiepileptic drug that can be used as add-on therapy to standard antiepileptic drugs. To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with drug-resistant focal-onset epilepsy. For the latest update, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 13 July 2021) on 15 July 2021. There were no language or time restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. We searched for randomised placebo-controlled add-on studies of people of any age with drug-resistant focal seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel-group or cross-over design. Two review authors independently selected studies for inclusion and extracted information. In the case of disagreements, a third review author arbitrated. Review authors assessed the following outcomes: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. We included four randomised controlled trials, representing a total of 236 participants, in the review. Two trials had parallel-group design, the third had a two-period cross-over design, and the fourth had a three-period cross-over design. We judged all four studies to be at an unclear risk of bias overall. Bias arose from the incomplete reporting of methodological details, the incomplete and selective reporting of outcome data, and from participants having unstable drug regimens during experimental treatment in one trial. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the extracted data. Only one study reported the outcome of 50% or greater reduction in seizure frequency, whilst three studies reported percentage reduction in seizure frequency compared to placebo. One study claimed an average seizure reduction of 35.8% with add-on felbamate whilst another study claimed a more modest reduction of 4.2%. Both studies reported that seizure frequency increased with add-on placebo and that there was a significant difference in seizure reduction between felbamate and placebo (P = 0.0005 and P = 0.018, respectively). The third study reported a 14% reduction in seizure frequency with add-on felbamate but stated that the difference between treatments was not significant. There were conflicting results regarding treatment withdrawal. One study reported a higher treatment withdrawal for placebo-randomised participants, whereas the other three studies reported higher treatment withdrawal rates for felbamate-randomised participants. Notably, the treatment withdrawal rates for felbamate treatment groups across all four studies remained reasonably low (less than 10%), suggesting that felbamate may be well tolerated. Felbamate-randomised participants most commonly withdrew from treatment due to adverse effects. The adverse effects consistently reported by all four studies were headache, dizziness and nausea. All three adverse effects were reported by 23% to 40% of felbamate-treated participants versus 3% to 15% of placebo-treated participants. We assessed the evidence for all outcomes using GRADE and rated the evidence as very low certainty, meaning that we have little confidence in the findings reported. We mainly downgraded evidence for imprecision due to the narrative synthesis conducted and the low number of events. We stress that the true effect of felbamate could likely be significantly different from that reported in this current review update. In view of the methodological deficiencies, the limited number of included studies and the differences in outcome measures, we have found no reliable evidence to support the use of felbamate as an add-on therapy in people with drug-resistant focal-onset epilepsy. A large-scale, randomised controlled trial conducted over a longer period of time is required to inform clinical practice.

Vagus nerve stimulation for focal seizures.

This is an updated version of the Cochrane Review published in 2015. Epilepsy is a chronic neurological disorder, characterised by recurring, unprovoked seizures. Vagus nerve stimulation (VNS) is a neuromodulatory treatment that is used as an adjunctive therapy for treating people with drug-resistant epilepsy. VNS consists of chronic, intermittent electrical stimulation of the vagus nerve, delivered by a programmable pulse generator. To evaluate the efficacy and tolerability of VNS when used as add-on treatment for people with drug-resistant focal epilepsy. For this update, we searched the Cochrane Register of Studies (CRS), and MEDLINE Ovid on 3 March 2022. We imposed no language restrictions. CRS Web includes randomised or quasi-randomised controlled trials from the Specialised Registers of Cochrane Review Groups, including Epilepsy, CENTRAL, PubMed, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform. We considered parallel or cross-over, randomised, double-blind, controlled trials of VNS as add-on treatment, which compared high- and low-level stimulation (including three different stimulation paradigms: rapid, mild, and slow duty-cycle), and VNS stimulation versus no stimulation, or a different intervention. We considered adults or children with drug-resistant focal seizures who were either not eligible for surgery, or who had failed surgery. We followed standard Cochrane methods, assessing the following outcomes: 1. 50% or greater reduction in seizure frequency 2. Treatment withdrawal (any reason) 3. Adverse effects 4. Quality of life (QoL) 5. Cognition 6. Mood We did not identify any new studies for this update, therefore, the conclusions are unchanged. We included the five randomised controlled trials (RCT) from the last update, with a total of 439 participants. The baseline phase ranged from 4 to 12 weeks, and double-blind treatment phases from 12 to 20 weeks. We rated two studies at an overall low risk of bias, and three at an overall unclear risk of bias, due to lack of reported information about study design. Effective blinding of studies of VNS is difficult, due to the frequency of stimulation-related side effects, such as voice alteration. The risk ratio (RR) for 50% or greater reduction in seizure frequency was 1.73 (95% confidence interval (CI) 1.13 to 2.64; 4 RCTs, 373 participants; moderate-certainty evidence), showing that high frequency VNS was over one and a half times more effective than low frequency VNS. The RR for treatment withdrawal was 2.56 (95% CI 0.51 to 12.71; 4 RCTs, 375 participants; low-certainty evidence). Results for the top five reported adverse events were: hoarseness RR 2.17 (99% CI 1.49 to 3.17; 3 RCTs, 330 participants; moderate-certainty evidence); cough RR 1.09 (99% CI 0.74 to 1.62; 3 RCTs, 334 participants; moderate-certainty evidence); dyspnoea RR 2.45 (99% CI 1.07 to 5.60; 3 RCTs, 312 participants; low-certainty evidence); pain RR 1.01 (99% CI 0.60 to 1.68; 2 RCTs; 312 participants; moderate-certainty evidence); paraesthesia 0.78 (99% CI 0.39 to 1.53; 2 RCTs, 312 participants; moderate-certainty evidence). Results from two studies (312 participants) showed that a small number of favourable QOL effects were associated with VNS stimulation, but results were inconclusive between high- and low-level stimulation groups. One study (198 participants) found inconclusive results between high- and low-level stimulation for cognition on all measures used. One study (114 participants) found the majority of participants showed an improvement in mood on the Montgomery-Åsberg Depression Rating Scale compared to baseline, but results between high- and low-level stimulation were inconclusive. We found no important heterogeneity between studies for any of the outcomes. VNS for focal seizures appears to be an effective and well-tolerated treatment. Results of the overall efficacy analysis show that high-level stimulation reduced the frequency of seizures better than low-level stimulation. There were very few withdrawals, which suggests that VNS is well tolerated. Adverse effects associated with implantation and stimulation were primarily hoarseness, cough, dyspnoea, pain, paraesthesia, nausea, and headache, with hoarseness and dyspnoea more likely to occur with high-level stimulation than low-level stimulation. However, the evidence for these outcomes is limited, and of moderate to low certainty. Further high-quality research is needed to fully evaluate the efficacy and tolerability of VNS for drug-resistant focal seizures.

VNS parameters for clinical response in Epilepsy

BackgroundWhile vagus nerve stimulation (VNS) has been in use for over two decades, little professional guidance exists to describe dosing and titration of therapy which is the consequence of a limited amount of evidence developed during the pre-market phase of therapy development. Post-market surveillance of dosing practice has revealed significant deviations from dosing and titration guidance offered by professional societies as well as the manufacturer. ObjectiveThis analysis aims to identify a target dose for VNS Therapy in Epilepsy. MethodsHerein, VNS clinical outcomes are linked to the patient-specific dosing parameters for each study visit (n = 1178 patients). A generalized linear mixed model was built to ascertain the relationship between key stimulation parameters (i.e., Output Current, Pulse Width, Signal Frequency, and Duty Cycle) and clinical response, defined as a 50% or greater reduction in seizure frequency from baseline. Other demographic parameters of interest, such as duration of epilepsy and age at implant, were also explored. ResultsA population level target output current and duty cycle for VNS therapy for epilepsy was identified as 1.61 mA and 17.1% duty cycle. Patients with shorter duration of epilepsy were identified to have a higher likelihood to respond to VNS therapy (p < 0.001). While patients who were on the therapy longer were more likely to respond to the therapy, the effect did not interact with the dosing settings - suggesting that patients who have been chronically underdosed may still benefit from achieving the target dose. ConclusionAn opportunity exists to improve upon VNS outcomes by aligning clinical practice around this evidence-based target dose.

Pregabalin add-on for drug-resistant focal epilepsy.

Pregabalin add-on for drug-resistant focal epilepsy.

Brivaracetam add-on therapy for drug-resistant epilepsy.

This is an updated version of the Cochrane Review previously published in 2019. Epilepsy is one of the most common neurological disorders. It is estimated that up to 30% of individuals with epilepsy continue to have epileptic seizures despite treatment with an antiepileptic drug. These patients are classified as drug-resistant and require treatment with a combination of multiple antiepileptic drugs. Brivaracetam is a third-generation antiepileptic drug that is a high-affinity ligand for synaptic vesicle protein 2A. In this review we investigated the use of brivaracetam as add-on therapy for epilepsy. To evaluate the efficacy and tolerability of brivaracetam when used as add-on treatment for people with drug-resistant epilepsy. For the latest update we searched the following databases on 7 September 2021: the Cochrane Register of Studies (CRS Web); MEDLINE (Ovid) 1946 to 3 September 2021. CRS Web includes randomised controlled trials (RCTs) and quasi-RCTs from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, the Cochrane Central Register of Controlled Trials (CENTRAL), and the specialised registers of Cochrane Review Groups including Cochrane Epilepsy. We searched for parallel-group RCTs that recruited people of any age with drug-resistant epilepsy. We accepted studies with any level of blinding (double-blind, single-blind, or unblinded). In accordance with standard Cochrane methodological procedures, two review authors independently assessed trials for inclusion before evaluating trial quality and extracting relevant data. The primary outcome to be assessed was 50% or greater reduction in seizure frequency. Secondary outcomes were: seizure freedom, treatment withdrawal for any reason, treatment withdrawal due to adverse events, the proportion of participants who experienced any adverse events, and drug interactions. We used an intention-to-treat population for all primary analyses, and presented results as risk ratios (RRs) with 95% confidence intervals (CIs). We did not identify any new studies for this update, therefore the results and conclusions of the review are unchanged. The previous review included six studies involving a total of 2411 participants. Only one study included participants with both focal and generalised onset seizures; the other five trials included participants with focal onset seizures only. Study participants were aged 16 to 80 years. Treatment periods ranged from 7 to 16 weeks. We judged two studies to have low risk of bias and four to have unclear risk of bias. Details on the method used for allocation concealment and how blinding was maintained were insufficient in one study each. One study did not report all outcomes prespecified in the trial protocol, and there were discrepancies in reporting in a further study. Participants receiving brivaracetam add-on were more likely to experience a 50% or greater reduction in seizure frequency than those receiving placebo (RR 1.81, 95% CI 1.53 to 2.14; 6 studies; moderate-certainty evidence). Participants receiving brivaracetam were more likely to attain seizure freedom; however, the evidence is of low certainty (RR 5.89, 95% CI 2.30 to 15.13; 6 studies). The incidence of treatment withdrawal for any reason was slightly greater for participants receiving brivaracetam compared to those receiving placebo (RR 1.27, 95% CI 0.94 to 1.74; 6 studies; low-certaintyevidence). The risk of participants experiencing one or more adverse events did not differ significantly following treatment with brivaracetam compared to placebo (RR 1.08, 95% CI 1.00 to 1.17; 5 studies; moderate-certainty evidence). However, participants receiving brivaracetam did appear to be more likely to withdraw from treatment due to adverse events compared with those receiving placebo (RR 1.54, 95% CI 1.02 to 2.33; 6 studies; low-certaintyevidence). When used as add-on therapy for individuals with drug-resistant epilepsy, brivaracetam may be effective in reducing seizure frequency and may aid patients in achieving seizure freedom. However, add-on brivaracetam is probably associated with a greater proportion of treatment withdrawals due to adverse events compared with placebo. It is important to note that only one of the eligible studies included participants with generalised epilepsy. None of the included studies involved participants under the age of 16, and all studies were of short duration. Consequently, the findings of this review are mainly applicable to adult patients with drug-resistant focal epilepsy. Future research should focus on investigating the tolerability and efficacy of brivaracetam during longer-term follow-up, as well as assess the efficacy and tolerability of add-on brivaracetam in managing other types of seizures and in other age groups.

Carisbamate add-on therapy for drug-resistant focal epilepsy.

Epilepsy is one of the most common neurological disorders. Many people with epilepsy are drug-resistant and require add-on therapy, meaning that they concomitantly take multiple antiepileptic drugs. Carisbamate is a drug which is taken orally and inhibits voltage-gated sodium channels. Carisbamate may be useful for drug-resistant focal epilepsy. To evaluate the efficacy and tolerability of carisbamate when used as an add-on therapy for drug-resistant focal epilepsy. We searched the following databases on 8 April 2021: Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid) 1946 to April 07, 2021. CRS Web includes randomised or quasi-randomised controlled trials from PubMed, Embase, ClinicalTrials.gov, WHO ICTRP, the Cochrane Central Register of Controlled Trials (CENTRAL), and the specialised registers of Cochrane review groups including Epilepsy. We also searched ongoing trials registers, checked reference lists, and contacted authors of the included trials. Double-blind randomised controlled trials (RCTs) comparing carisbamate versus placebo or another antiepileptic drug, as add-on therapy for drug-resistant focal epilepsy. Trials could have a parallel-group or cross-over design. Two review authors independently selected the trials for inclusion, assessed trial quality, and extracted data. The primary outcome was 50% or greater reduction in seizure frequency (responder rate). The secondary outcomes were: seizure freedom, treatment withdrawal (for any reason and due to adverse events); adverse events, and quality of life. We analysed data using the Mantel-Haenszel statistical method and according to the intention-to-treat population. We presented results as risk ratios (RRs) with 95% confidence intervals (CIs). We included four RCTs involving a total of 2211 participants. All four trials compared carisbamate with placebo for drug-resistant focal epilepsy. Participants in all trials were over 16 years of age and received at least one other antiepileptic drug concomitantly. We detected substantial risk of bias across the included trials. All four trials were at high risk of attrition bias due to the incomplete reporting of attrition and the high treatment withdrawal rates noted, especially with higher doses. All four trials also had unclear risk of detection bias, as they did not specify whether outcome assessors were blinded. Meta-analysis suggested that carisbamate produced a higher responder rate compared to placebo (RR 1.36, 95% CI 1.14 to 1.62; 4 studies; moderate-certainty evidence). More participants in the carsibamate group achieved seizure freedom (RR 2.43, 95% CI 0.84 to 7.03; 1 study); withdrew from treatment for any reason (RR 1.32, 95% CI 0.82 to 2.12; 4 studies); and withdrew from treatment due to adverse events (RR 1.80, 95% CI 0.78 to 4.17; 4 studies) than in the placebo group. However, the evidence for the three outcomes was very low-certainty. There was no difference between treatment groups for the proportion of participants experiencing at least one adverse event (RR 1.10, 95% CI 0.93 to 1.30; 2 studies; low-certainty evidence). More participants in the carisbamate group than in the placebo group developed dizziness (RR 2.06, 95% CI 1.23 to 3.44; 4 studies; very low-certainty evidence) and somnolence (RR 1.82, 95% CI 1.28 to 2.58; 4 studies; low-certainty evidence), but not fatigue (RR 1.11, 95% CI 0.73 to 1.68; 3 studies); headache (RR 1.13, 95% CI 0.92 to 1.38; 4 studies); or nausea (RR 1.19, 95% CI 0.81 to 1.75; 3 studies). None of the included trials reported quality of life. The results suggest that carisbamate may demonstrate efficacy and tolerability as an add-on therapy for drug-resistant focal epilepsy. Importantly, the evidence for all outcomes except responder rate was of low to very low certainty, therefore we are uncertain of the accuracy of the reported effects. The certainty of the evidence is limited by the significant risk of bias associated with the included studies, as well as the statistical heterogeneity detected for some outcomes. Consequently, it is difficult for these findings to inform clinical practice. The studies were all of short duration and only included adult study populations. There is a need for further RCTs with more clear methodology, long-term follow-up, more clinical outcomes, more seizure types, and a broader range of participants.

Eslicarbazepine acetate add-on therapy for drug-resistant focal epilepsy.

This is an update of a review first published in 2011, and last updated in 2017. Most people with epilepsy have a good prognosis, but up to 30% of people continue to have seizures despite several regimens of antiepileptic drugs. In this review, we summarized the current evidence regarding eslicarbazepine acetate (ESL) when used as an add-on treatment for drug-resistant focal epilepsy. To evaluate the efficacy and tolerability of ESL when used as an add-on treatment for people with drug-resistant focal epilepsy. For this update, we searched the following databases on 10 September 2020: Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid). CRS Web includes randomized or quasi-randomized, controlled trials from Specialized Registers of Cochrane Review Groups including Epilepsy, CENTRAL, PubMed, Embase, ClinicalTrials.gov and the WHO ICTRP. There were no language restrictions. We reviewed the reference lists of retrieved studies and contacted the manufacturers of ESL and experts in the field for information about any unpublished or ongoing studies. Randomized placebo-controlled double-blind add-on trials of ESL in people with drug-resistant focal epilepsy. Two review authors independently selected trials for inclusion and extracted data. Outcomes investigated included 50% or greater reduction in seizure frequency, seizure freedom, treatment withdrawal, adverse effects and drug interactions. Primary analyses were by intention to treat (ITT). The dose-response relationship was evaluated in regression models. We included seven trials (2185 participants, aged 2 to 77 years), which were at low or unclear risk of bias apart from a high risk of attrition bias; all studies were funded by the pharmaceutical company, BIAL. The overall risk ratio (RR) for 50% or greater reduction in seizure frequency was 1.57 (95% confidence interval (CI) 1.34 to 1.83). For adults, the RR was 1.71 (95% CI 1.42 to 2.05; 5 studies, 1799 participants; moderate-certainty evidence); for children aged six to 18 years, the RR was 1.35 (95% CI 0.98 to 1.87; 2 studies, 322 participants; moderate-certainty evidence). Dose regression analysis showed evidence that ESL reduced seizure frequency with an increase in efficacy with increasing doses of ESL. ESL was associated with seizure freedom (RR 3.16, 95% CI 1.73 to 5.78; 6 studies, 1922 participants; moderate-certainty evidence). Participants were more likely to have ESL withdrawn for adverse effects (RR 2.72, 95% CI 1.66 to 4.46; 7 studies, 2185 participants; moderate-certainty evidence), but not for any reason (RR 1.25, 95% CI 0.93 to 1.70; 7 studies, 2185 participants; moderate-certainty evidence). The following adverse effects were associated with ESL: dizziness (RR 2.77, 99% CI 1.85 to 4.15); nausea (RR 2.55, 99% CI 1.39 to 4.67); somnolence (RR 1.75, 99% CI 1.18 to 2.61); diplopia (RR 4.07, 99% CI 1.86 to 8.89); and vomiting (RR 2.37, 99% CI 1.19 to 4.74). Overall, the certainty of the evidence was moderate due to a high discontinuation rate in studies of adults. ESL reduces seizure frequency when used as an add-on treatment for adults with drug-resistant focal epilepsy. The trials included in this review were of short-term duration. In addition, this update found that ESL may reduce seizure frequency in children from 6 to 18 years of age; however the results are inconclusive.

Lacosamide add-on therapy for focal epilepsy.

This is an updated version of the Cochrane review published in 2015. Around half of people with epilepsy will not achieve seizure freedom on their first antiepileptic drug; many will require add-on therapy. Around a third of people fail to achieve complete seizure freedom despite multiple antiepileptic drugs. Lacosamide has been licenced as an add-on therapy for drug-resistant focal epilepsy. To evaluate the efficacy and tolerability of lacosamide as an add-on therapy for children and adults with drug-resistant focal epilepsy. We searched the following databases (22 August 2019): the Cochrane Register of Studies (CRS Web), including the Cochrane Epilepsy Group Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid, 1946 to 20 August 2019), ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP), with no language restrictions. We contacted UCB Pharma (sponsors of lacosamide). Randomised controlled trials of add-on lacosamide in people with drug-resistant focal epilepsy. We used standard Cochrane methodology, assessing the following outcomes: 50% or greater reduction in seizure frequency; seizure freedom; treatment withdrawal; adverse events; quality of life; and cognitive changes. The primary analyses were intention-to-treat. We estimated summary risk ratios (RR) for each outcome presented with 99% confidence intervals (CI), except for 50% or greater seizure reduction, seizure freedom and treatment withdrawal which were presented with 95% CIs. We performed subgroup analyses according to lacosamide dose and sensitivity analyses according to population age, whereby data from children were excluded from the meta-analysis. We included five trials (2199 participants). The risk of bias for all studies was low to unclear. All studies were placebo-controlled and assessed doses from 200 mg to 600 mg per day. One study evaluated lacosamide in children; all other studies were in adults. Trial duration ranged from 24 to 26 weeks. All studies used adequate methods of randomisation and were double-blind. Overall, the certainty of the evidence for the outcomes was judged as moderate to high, with the exception of seizure freedom which was low. The RR for a 50% or greater reduction in seizure frequency for all doses of lacosamide compared with placebo was 1.79 (95% CI 1.55 to 2.08; 5 studies; 2199 participants; high-certainty evidence). The RR for seizure freedom for all doses of lacosamide compared with placebo was 2.27 (95% CI 1.35 to 3.83; 5 studies; 2199 participants; low-certainty evidence). The RR for treatment withdrawal for all doses of lacosamide compared with placebo was 1.57 (95% CI 1.24 to 1.98; 5 studies; 2199 participants; moderate-certainty evidence). The estimated effect size for most outcomes did not change considerably following sensitivity analysis. For seizure freedom, however, the RR nearly doubled upon the exclusion of data from children (RR 4.04, 95% CI 1.52 to 10.73). Adverse events associated with lacosamide included: abnormal co-ordination (RR 6.12, 99% CI 1.35 to 27.77), blurred vision (RR 4.65, 99% CI 1.24 to 17.37), diplopia (RR 5.59, 99% CI 2.27 to 13.79), dizziness (RR 2.96, 99% CI 2.09 to 4.20), nausea (RR 2.35, 99% CI 1.37 to 4.02), somnolence (RR 2.04, 99% CI 1.22 to 3.41), vomiting (RR 2.94, 99% CI 1.54 to 5.64), and number of participants experiencing one or more adverse events (RR 1.12, 99% CI 1.01 to 1.24). Adverse events that were not significant were: vertigo (RR 3.71, 99% CI 0.86 to 15.95), rash (RR 0.58, 99% CI 0.17 to 1.89), nasopharyngitis (RR 1.41, 99% CI 0.87 to 2.28), headache (RR 1.34, 99% CI 0.90 to 1.98), fatigue (RR 2.11, 99% CI 0.92 to 4.85), nystagmus (RR 1.47, 99% CI 0.61 to 3.52), and upper respiratory tract infection (RR 0.70, 99% CI 0.43 to 1.15). Lacosamide is effective and well-tolerated in the short term when used as add-on treatment for drug-resistant focal epilepsy. Lacosamide increases the number of people with 50% or greater reduction in seizure frequency and may increase seizure freedom, compared to placebo. Higher doses of lacosamide may be associated with higher rates of adverse events and treatment withdrawal. Additional evidence is required assessing the use of lacosamide in children and on longer-term efficacy and tolerability.

Efficacy and tolerability of lamotrigine in the treatment of focal epilepsy among children and adolescents: a meta-analysis.

BackgroundEpilepsy is the most common chronic neurological disease in children, and focal epileptic seizures are the most common subtype. Unlike the data supporting treatment options for adults with epilepsy, evidence regarding the most effective first-line drug therapy for focal epilepsy in children and adolescents is limited. While lamotrigine is a therapeutic option for adults, there are disagreements surrounding its efficacy and tolerability in the younger population. Therefore, we performed a meta-analysis to determine if there was sufficient evidence to support a more definitive recommendation.MethodsWe undertook electronic search strategies using Medline via Ovid SP, Embase via Ovid SP up to February 05, 2021. We also searched relevant articles through Chinese BioMedical Literature (CBM), Chinese National Knowledge Infrastructure (CNKI), WANFANG, and VIP databases up to February 05, 2021. Study selection and data extraction were performed by 2 authors independently. The randomized controlled trials on focal epilepsy in children were included, and we made risk of bias judgments based on the methods endorsed by The Cochrane Collaboration. We used fifty percent or greater reduction in seizure frequency as an indicator of efficacy, the incidence of adverse events and treatment withdrawal as indicators of tolerability. The strength of the correlation was assessed via risk ratios (RRs) and their 95% confidence intervals (95% CIs).ResultsA total of 7 randomized trials involving 757 participants fulfilled the eligibility criteria. Of the 7 trials, 3 were placebo-controlled, and 4 compared lamotrigine with carbamazepine or oxcarbazepine. Lamotrigine was significantly more effective than placebo in achieving ≥50% reduction in seizure frequency, but its efficacy was not significantly different from that of carbamazepine or oxcarbazepine (lamotrigine vs. placebo: RR 2.95, 95% CI, 1.88 to 4.61; lamotrigine vs. carbamazepine/oxcarbazepine: RR 0.95, 95% CI, 0.85 to 1.05. There was significant difference in the incidence of overall adverse events between the lamotrigine- and carbamazepine/oxcarbazepine-treated groups (RR 0.64, 95% CI, 0.45 to 0.90).ConclusionsLamotrigine was effective in reducing the seizure frequency when used as an add-on treatment in children with focal epilepsy, but current evidence does not suggest that lamotrigine is superior to carbamazepine/oxcarbazepine as monotherapy. For overall adverse events, lamotrigine has significantly fewer than carbamazepine/oxcarbazepine, suggesting that lamotrigine has better tolerability.

Is sulthiame effective and tolerated as add-on therapy for infants with epilepsy? A Cochrane Review summary with commentary.

Is sulthiame effective and tolerated as add-on therapy for infants with epilepsy? A Cochrane Review summary with commentary.

Ethosuximide, sodium valproate or lamotrigine for absence seizures in children and adolescents.

This is an updated version of the Cochrane Review previously published in 2019. Absence seizures (AS) are brief epileptic seizures which present in childhood and adolescence. Depending on clinical features and electroencephalogram (EEG) findings they are divided into typical, atypical absences, and absences with special features. Typical absences are characterised by sudden loss of awareness and an EEG typically shows generalised spike wave discharges at three cycles per second. Ethosuximide, valproate and lamotrigine are currently used to treat absence seizures. This review aims to determine the best choice of antiepileptic drug for children and adolescents with AS. To review the evidence for the effects of ethosuximide, valproate and lamotrigine as treatments for children and adolescents with absence seizures (AS), when compared with placebo or each other. For the latest update we searched the Cochrane Register of Studies (CRS Web, 22 September 2020) and MEDLINE (Ovid, 1946 to September 21, 2020). CRS Web includes randomised or quasi-randomised, controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialized Registers of Cochrane Review Groups including Epilepsy. No language restrictions were imposed. In addition, we contacted Sanofi Winthrop, Glaxo Wellcome (now GlaxoSmithKline) and Parke Davis (now Pfizer), manufacturers of sodium valproate, lamotrigine and ethosuximide respectively. Randomised parallel group monotherapy or add-on trials which include a comparison of any of the following in children or adolescents with AS: ethosuximide, sodium valproate, lamotrigine, or placebo. Outcome measures were: 1. proportion of individuals seizure free at one, three, six, 12 and 18 months post randomisation; 2. individuals with a 50% or greater reduction in seizure frequency; 3. normalisation of EEG and/or negative hyperventilation test; and 4. adverse effects. Data were independently extracted by two review authors. Results are presented as risk ratios (RR) with 95% confidence intervals (95% CIs). We used GRADE quality assessment criteria to evaluate the certainty of evidence for the outcomes derived from all included studies. On the basis of our selection criteria, we included no new studies in the present review. Eight small trials (total number of participants: 691) were included from the earlier review. Six of them were of poor methodological quality (unclear or high risk of bias) and seven recruited less than 50 participants. There are no placebo-controlled trials for ethosuximide or valproate, and hence, no evidence from randomised controlled trials (RCTs) to support a specific effect on AS for either of these two drugs. Due to the differing methodologies used in the trials comparing ethosuximide, lamotrigine and valproate, we thought it inappropriate to undertake a meta-analysis. One large randomised, parallel double-blind controlled trial comparing ethosuximide, lamotrigine and sodium valproate in 453 children with newly diagnosed childhood absence epilepsy found that at 12 months, seizure freedom was higher in patients taking ethosuximide (70/154, 45%) than in patients taking lamotrigine (31/146, 21%; P < 0.001), with no difference between valproate (64/146, 44%) and ethosuximide (70/154, 45%; P > 0.05). In this study, the frequency of treatment failures due to intolerable adverse events was significantly different among the treatment groups, with the largest proportion of adverse events in the valproic acid group (48/146, 33%) compared to the ethosuximide (38/154, 25%) and the lamotrigine (29/146, 20%) groups (P < 0.037). Overall, this large study demonstrates the superior effectiveness of ethosuximide and valproic acid compared to lamotrigine as initial monotherapy aimed to control seizures without intolerable adverse effects in children with childhood absence epilepsy. This study provided high certainty of the evidence for outcomes for which data were available. However, the certainty of the evidence provided by the other included studies was low, primarily due to risk of bias and imprecise results because of the small sample sizes. Hence, conclusions regarding the efficacy of ethosuximide, valproic acid and lamotrigine derive mostly from this single study. Since the last version of this review was published, we have found no new studies. Hence, the conclusions remain the same as the previous update. With regards to both efficacy and tolerability, ethosuximide represents the optimal initial empirical monotherapy for children and adolescents with AS. However, if absence and generalised tonic-clonic seizures coexist, valproate should be preferred, as ethosuximide is probably inefficacious on tonic-clonic seizures.

Rufinamide add-on therapy for drug-resistant epilepsy.

Rufinamide add-on therapy for drug-resistant epilepsy.

Adjunctive Cenobamate for Focal-Onset Seizures in Adults: A Systematic Review and Meta-Analysis.

BackgroundCenobamate is a novel tetrazole-derived carbamate compound with a dual mechanism of action. This drug can enhance the inactivated state of voltage-gated sodium channels, preferentially inhibiting the persistent component of the sodium channel current, and acts as a positive allosteric modulator of GABAA receptors, binding at a non-benzodiazepine site.ObjectiveWe assessed the efficacy and safety of adjunctive cenobamate for the treatment of focal-onset seizures in adult patients with epilepsy using meta-analytical techniques.MethodsWe systematically searched (May, week 4, 2020) MEDLINE (accessed by PubMed), the Cochrane Central Register of Controlled Trials (CENTRAL), and the US National Institutes of Health Clinical Trials Registry (http://www.clinicaltrials.gov). There were no date limitations or language restrictions. Randomized, placebo-controlled, single or double-blinded, add-on trials of cenobamate in adult patients with uncontrolled focal-onset seizures were identified. Main outcomes included the proportion of patients with ≥ 50 and 100% reduction in seizure frequency during the maintenance treatment period compared with baseline and the incidence of treatment withdrawal and adverse events (AEs). Risk ratio (RR) with 95% confidence interval (CI) was estimated for each outcome.ResultsTwo trials were included, overall enrolling 659 patients (442 for the add-on cenobamate group and 217 for the add-on placebo group). Seizure frequency reduction by at least 50% occurred during the maintenance phase in 50.1% of the patients randomized to cenobamate and 23.5% of the placebo-treated participants (RR 2.18, 95% CI 1.67–2.85; p < 0.001). The pooled estimated RR to achieve seizure freedom for the cenobamate group in comparison with placebo was 3.71 (95% CI 1.93–7.14; p < 0.001). Withdrawal from randomized treatment occurred in 16.7 and 11.1% of participants receiving cenobamate and placebo, respectively (RR 1.34, 95% CI 0.85–2.09; p = 0.205). Treatment was discontinued due to AEs in 12.2 and 4.1% of the patients in the active and control arms (RR 2.27, 95% CI 1.08–4.79; p = 0.031). AEs were reported in 76.9 and 66.8% of the patients during treatment with cenobamate and placebo (RR 1.14, 95% CI 1.02–1.26; p = 0.021). The cenobamate-associated AEs included somnolence, dizziness, fatigue, balance disorder, and diplopia.ConclusionsAdjunctive cenobamate in adult patients with uncontrolled focal-onset seizures is associated with a greater reduction in seizure frequency and a higher rate of AEs than placebo.Electronic supplementary materialThe online version of this article (10.1007/s40263-020-00759-9) contains supplementary material, which is available to authorized users.

Improving the effectiveness of ANT DBS therapy for epilepsy with optimal current targeting.

ObjectiveDeep brain stimulation of the ANT is a novel treatment option in refractory epilepsy with an established efficacy at the group level. However, data on the effect of individualized programming are currently lacking. We report the effect of programming changes on outcome in deep brain stimulation of anterior nucleus of thalamus (ANT DBS). Secondly, we investigated whether the effect differs between seizure types. Thirdly, we compared the response status between patients with stimulation contacts verified inside the ANT with patients with contacts located outside of ANT.MethodsThe participants were 27 consecutive patients with ANT DBS implantation with at least two‐year follow‐up. Seizures were subdivided into focal aware (FAS), focal impaired awareness (FIAS), and focal to bilateral tonic‐clonic seizures (FBTCS). The patients’ seizure diaries were analyzed retrospectively to assess changes in different seizure types. Active contact locations for each patient were verified from preoperative MRI and postoperative CT fusion images using SureTune III (Medtronic Inc, Minneapolis, MN) software.ResultsA significant reduction in monthly mean seizure frequency occurred in FIAS: 56% at two‐year and 65% at five‐year follow‐up. The effects on FAS and FBTCS were less pronounced. Patients with contacts inside the ANT or on the anterolateral border of ANT experienced a greater reduction in seizure frequency than patients with outside‐ANT contacts. Ultimately, seven patients became responders due to changes in DBS programming or repositioning of contacts, increasing our responder rate from 44% to 70% as measured by a seizure reduction of at least 50%.SignificanceANT DBS appears to be especially effective in reducing FIAS, when the appropriately chosen contacts are activated.

Vigabatrin add-on therapy for drug-resistant focal epilepsy.

This is an updated version of the original Cochrane Review published in 2008 and updated in 2013. Epilepsy is a common neurological condition which affects up to 1% of the population. Approximately 30% of people with epilepsy do not respond to treatment with currently available drugs. The majority of these people have focal epilepsy. Vigabatrin is an antiepileptic drug licensed for use in drug-resistant epilepsy. To assess the efficacy and tolerability of vigabatrin as an add-on therapy for people with drug-resistant focal epilepsy. For the latest update of this review, we searched the following databases on 1 November 2018: Cochrane Register of Studies (CRS Web), MEDLINE (Ovid 1946 to 31 October 2018), ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform. The Cochrane Epilepsy Group Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL) are both included in the Cochrane Register of Studies (CRS Web). We checked reference lists of retrieved studies for additional reports of relevant studies and contacted Hoechst Marion Roussel (manufacturers of vigabatrin) in 2000. We included randomised, double-blind, placebo-controlled, fully published trials of vigabatrin in people of any age with drug-resistant focal epilepsy. Two review authors assessed trials for inclusion and extracted data using the standard methodological procedures expected by Cochrane. Primary analysis was by intention-to-treat (ITT). We evaluated: 50% or greater reduction in seizure frequency, treatment withdrawal, adverse effects, dose-response analysis, cognitive outcomes and quality of life. We presented results as risk ratios (RR) with 95% or 99% confidence intervals (CI). We identified 11 trials that included 756 participants (age range: 10 to 64 years). The trials tested vigabatrin doses between 1 g/day and 6 g/day. All 11 trials displayed a risk of bias across at least three risk of bias domains. Predominantly, the risk of bias was associated with: allocation concealment (selection bias), blinding of outcome assessment (detection bias) and incomplete outcome data (attrition bias). Participants treated with vigabatrin may be two to three times more likely to obtain a 50% or greater reduction in seizure frequency compared with those treated with placebo (RR 2.60, 95% CI 1.87 to 3.63; 4 studies; low-certainty evidence). Those treated with vigabatrin may also be three times more likely to have treatment withdrawn although we are uncertain (RR 2.86, 95% CI 1.25 to 6.55; 4 studies; very low-certainty evidence). Compared to placebo, participants given vigabatrin were more likely to experience adverse effects: dizziness/light-headedness (RR 1.74, 95% CI 1.05 to 2.87; 9 studies; low-certainty evidence), fatigue (RR 1.65, 95% CI 1.08 to 2.51; 9 studies; low-certainty evidence), drowsiness (RR 1.70, 95% CI 1.18 to 2.44; 8 studies) and depression (RR 3.28, 95% CI 1.30 to 8.27; 6 studies). Although the incidence rates were higher among participants receiving vigabatrin compared to those receiving placebo, the effect was not significant for the following adverse effects: ataxia (RR 2.76, 95% CI 0.96 to 7.94; 7 studies; very low-certainty evidence), nausea (RR 3.57, 95% CI 0.63 to 20.30; 4 studies), abnormal vision (RR 1.64, 95% CI 0.67 to 4.02; 5 studies; very low-certainty evidence), headache (RR 1.23, 95% CI 0.79 to 1.92; 9 studies), diplopia (RR 1.76, 99% CI 0.94 to 3.30) and nystagmus (RR 1.53, 99% CI 0.62 to 3.76; 2 studies; low-certainty evidence). Vigabatrin had little to no effect on cognitive outcomes or quality of life. Vigabatrin may significantly reduce seizure frequency in people with drug-resistant focal epilepsy. The results largely apply to adults and should not be extrapolated to children under 10 years old. Short-term follow-up of participants showed that some adverse effects were associated with its use. Analysis of longer-term observational studies elsewhere, however, has demonstrated that vigabatrin use can lead to the development of visual field defects.