Use of fenfluramine in MECP2-related Rett syndrome: Findings from a retrospective multicenter pediatric case series.

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Use of fenfluramine in MECP2-related Rett syndrome: Findings from a retrospective multicenter pediatric case series.

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  • Cite Count Icon 12
  • 10.1016/j.yebeh.2021.108061
Raising the bar: Fenfluramine sets new treatment standards for Dravet syndrome
  • May 28, 2021
  • Epilepsy & Behavior
  • Joseph Sullivan + 1 more

Raising the bar: Fenfluramine sets new treatment standards for Dravet syndrome

  • Supplementary Content
  • 10.1007/s40120-025-00713-1
Expert-Agreed Practical Recommendations on the Use of Fenfluramine in Developmental and Epileptic Encephalopathies Based on Clinical Experience and Literature Review
  • Feb 23, 2025
  • Neurology and Therapy
  • Vicente Villanueva + 6 more

IntroductionFenfluramine (FFA) represents the latest therapeutic option approved for seizure management in Dravet syndrome (DS) and Lennox–Gastaut syndrome (LGS) for patients aged ≥ 2 years. This article provides expert guidance for optimizing FFA therapy to support clinical decision-making in these populations.MethodsA panel of Spanish experts specialized in developmental epileptic encephalopathies (DEEs) has developed practical recommendations for the clinical use of FFA, focusing on key aspects of FFA management: mechanism of action, pharmacokinetics including drug interactions, titration, efficacy, safety and tolerability, contraindications, and considerations for its broader application in DEEs. The methodology adopted in this project was an expert-opinion, evidence-based approach.ResultsThe panel issued targeted recommendations, including a modified titration strategy slower than the product guidelines, adjusted for possible antiseizure concomitant medications, and management of other concomitant treatments. Key efficacy indicators, such as reductions in seizure frequency and severity of the most disabling seizures, were emphasized as core measures for treatment evaluation. Periodic assessments of non-seizure outcomes and daily life activities are recommended during follow-up to comprehensively capture treatment outcomes. The panel noted that their clinical observations align with positive findings from clinical trials, suggesting a potential role for FFA in other DEEs, tailored to individual electroclinical and etiological profiles.ConclusionThis article presents expert practical recommendations for the management and treatment optimization of FFA in patients with DEEs, supporting clinicians in achieving improved patient outcomes.

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  • Cite Count Icon 12
  • 10.1002/14651858.cd011772.pub3
Rufinamide add-on therapy for drug-resistant epilepsy.
  • Nov 8, 2020
  • The Cochrane database of systematic reviews
  • Mariangela Panebianco + 2 more

For people with drug-resistant focal epilepsy, rufinamide when used as an add-on treatment was effective in reducing seizure frequency. However, the trials reviewed were of relatively short duration and provided no evidence for long-term use of rufinamide. In the short term, rufinamide as an add-on was associated with several adverse events. This review focused on the use of rufinamide in drug-resistant focal epilepsy, and the results cannot be generalised to add-on treatment for generalised epilepsies. Likewise, no inference can be made about the effects of rufinamide when used as monotherapy.

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  • Cite Count Icon 68
  • 10.1016/j.ejpn.2010.09.003
Clinical course of young patients with Dravet syndrome after vagal nerve stimulation
  • Oct 23, 2010
  • European Journal of Paediatric Neurology
  • Nelia Zamponi + 3 more

Clinical course of young patients with Dravet syndrome after vagal nerve stimulation

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  • Cite Count Icon 43
  • 10.1016/j.yebeh.2018.09.014
Improved quality of life and cognition after early vagal nerve stimulator implantation in children
  • Sep 27, 2018
  • Epilepsy & Behavior
  • Jehuda Soleman + 7 more

Improved quality of life and cognition after early vagal nerve stimulator implantation in children

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  • Cite Count Icon 12
  • 10.1016/j.yebeh.2021.107935
Efficacy and tolerability of adjuvant perampanel: an Australian multicenter real-world observational study in refractory focal and generalized epilepsy syndromes
  • Apr 27, 2021
  • Epilepsy & Behavior
  • Parveen Sagar + 11 more

Efficacy and tolerability of adjuvant perampanel: an Australian multicenter real-world observational study in refractory focal and generalized epilepsy syndromes

  • Research Article
  • 10.21926/obm.genet.2402234
Prevention of Drug Resistant Epilepsy and Developmental Epileptic Encephalopathy: Preventative Vigabatrin Treatment in Tuberous Sclerosis Complex and the Case for Fenfluramine Treatment of Children with Newly Diagnosed Dravet Syndrome
  • May 8, 2024
  • OBM Genetics
  • Amanda Pong + 1 more

Tuberous sclerosis complex (TSC) is caused by mutations of hamartin (TSC1) or tuberin (TSC2) resulting in disinhibition of the mTOR pathway of cellular proliferation and differentiation and severe neurocognitive impairment, intractable epilepsy and tumors. Epilepsy develops in ~90% folllowed by drug-resistant epilepsy (DRE). Recently, prevention of DRE and developmental encephalopathy was shown to be possible in TSC using early administration of vigabatrin. For the first time, medical treatment successfully prevented epilepsy and reduced neurocognitive and behavioural co-morbidities. The crucial difference between the preventive and standard treatment groups was the timing of treatment initiation, not the type of the intervention. This paradigm can be extended to patients with other genetic or acquired conditions, including Dravet Syndrome (DS), a severe developmental epileptic encephalopathy (DEE) with DRE and high mortality, due to a de novo mutation of the gene SCN1A which codes for the sodium channel protein <em>a</em> subunit Na<sub>v</sub>1.1. Infants usually develop normally until their first seizure, commonly between 2-15 months. This is followed by DRE and developmental regression. Randomized controlled trials (RCTs) of adjunctive fenfluramine treatment in DS reduced median convulsive seizure frequency by 55.7% over placebo at 0.7 mg/kg/day. 50% of children had 75% seizure frequency reduction, 8% had convulsive seizure freedom versus 0% with placebo, and 18% had only one convulsive seizure versus 0% with placebo. Other pivotal studies showed similar results and efficacy was sustained in for <3 years. Fenfluramine is now a first-line therapy for DS. Given the existence of a remarkably effective treatment fenfluramine for Dravet, preventive therapy presents itself as a natural extension for its application. We hypothesize that not only may seizure outcomes such as time to second seizure and evolution to DRE be positively impacted, but moreover, protective effects on mortality and cognitive outcomes may also be seen.

  • Peer Review Report
  • 10.7554/elife.78877.sa0
Editor's evaluation: Disease-modifying effects of sodium selenate in a model of drug-resistant, temporal lobe epilepsy
  • Aug 4, 2022
  • Helen Scharfman

According to the World Health Organization (WHO), there are around 50 million people with epilepsy worldwide. Although drugs are available to control epileptic seizures, these only provide symptomatic relief. They cannot prevent the condition from worsening, and if people with epilepsy stop taking their medication, there is no lasting effect on the severity or frequency of their seizures. Some epilepsy cases are also resistant to these drugs. This is particularly common in adults with temporal epilepsy, with 30% of people continuing to suffer with seizures despite receiving medication. Current treatments also have no effect on problems with learning, memory and mental health that sometimes accompany drug-resistant epilepsy. Previous studies in animals have identified some potential treatments that could slow the progression of temporal epilepsy, but these have only been shown to work when used at a very early stage. Since most individuals with temporal epilepsy have already started having seizures when they are diagnosed (and it is difficult to predict who will develop the condition), these drugs are unlikely to be useful in practice. Here, Casillas-Espinosa et al. set out to find if a novel drug called sodium selenate can stop the progression of epilepsy and reduce the severity of temporal epilepsy when the condition is fully advanced. To do this, they used an animal model of temporal epilepsy, where rats had been modified to develop spontaneous seizures, resistance to normal anti-seizure medications, and problems with learning and memory. Casillas-Espinosa et al. found that sodium selenate not only reduced the number and severity of seizures in these model rats, but also improved their memory and learning ability. Several rats stopped having seizures altogether even after the treatment had stopped, indicating that sodium selenate had a long-lasting protective effect. Genetic analysis of the rats also revealed that shorter telomeres (special DNA sequences at the ends of chromosomes) correlated with increasing severity of the condition, suggesting that telomere length could help predict who might develop temporal epilepsy or respond best to treatment. This study identifies sodium selenate as a potential treatment that could reverse the progression of temporal epilepsy, even in individuals with advanced symptoms. Later this year, sodium selenate will be trialled in people with drug-resistant temporal epilepsy to determine if the drug benefits humans in the same way. Casillas-Espinosa et al. hope that it will improve participants’ epilepsy and, ultimately, their quality of life.

  • Research Article
  • Cite Count Icon 16
  • 10.1002/14651858.cd001901.pub3
Levetiracetam add-on for drug-resistant focal epilepsy.
  • Jun 30, 2020
  • The Cochrane database of systematic reviews
  • Gashirai K Mbizvo + 5 more

Drug resistance is common in focal epilepsy. In this update, we summarised the current evidence regarding add-on levetiracetam in treating drug-resistant focal epilepsy. The original review was published in 2001 and last updated in 2012. To evaluate the effectiveness of levetiracetam when used as an add-on treatment for people with drug-resistant focal epilepsy. We searched the Cochrane Register of Studies (CRS Web, which includes the Cochrane Epilepsy Group Specialized Register and CENTRAL), MEDLINE Ovid, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP) to November 2018. We contacted the manufacturers of levetiracetam and researchers in the field to seek any ongoing or unpublished trials. Randomised, placebo-controlled trials of add-on levetiracetam treatment in people with drug-resistant focal epilepsy. Two review authors independently selected trials for inclusion, assessed trials for bias, extracted data, and evaluated the overall certainty of the evidence. Outcomes investigated included 50% or greater reduction in focal seizure frequency (response), treatment withdrawal, adverse effects (including a specific analysis of changes in behaviour), cognitive effects, and quality of life (QoL). Primary analysis was intention-to-treat. We performed meta-analysis for all outcomes using a Mantel-Haenszel approach and calculated risk ratios (RR), with 95% confidence intervals (CI) for all estimates apart from adverse effects (99% CIs). We assessed heterogeneity using a Chi² test and the I² statistic. This update included 14 trials (2455 participants), predominantly possessing low risks of bias. Participants were adults in 12 trials (2159 participants) and children in the remaining two (296 participants). The doses of levetiracetam tested were 500 mg/day to 4000 mg/day in adults, and 60 mg/kg/day in children. Treatment ranged from 12 to 24 weeks. When individual doses were examined, levetiracetam at either 500 mg/day or 4000 mg/day did not perform better than placebo for the 50% or greater reduction in seizure frequency outcome (500 mg: RR 1.60, 95% CI 0.71 to 3.62; P = 0.26; 4000 mg: RR 1.64, 95% CI 0.59 to 4.57; P = 0.34). Levetiracetam was significantly better than placebo at all other individual doses (1000 mg to 3000 mg). RR was significantly in favour of levetiracetam compared to placebo when results were pooled across all doses (RR 2.37, 95% CI 2.02 to 2.78; 14 studies, 2455 participants; moderate-certainty evidence). Dose-response analysis demonstrated that the odds of achieving response (50% or greater reduction in seizure frequency) were increased by nearly 40% (odds ratio (OR) 1.39, 95% CI 1.23 to 1.58) for each 1000 mg increase in dose of levetiracetam. There were important levels of heterogeneity across multiple comparisons. Participants were not significantly more likely to experience treatment withdrawal with levetiracetam than with placebo (pooled RR 1.11, 95% CI 0.89 to 1.40; 13 studies, 2428 participants; high-certainty evidence). Somnolence was the most common adverse effect, affecting 13% of participants, and it was significantly associated with levetiracetam compared to placebo (pooled RR 1.62, 99% CI 1.19 to 2.20; 13 studies, 2423 participants; moderate-certainty evidence). Changes in behaviour were negligible in adults (1% affected; RR 1.79, 99% CI 0.59 to 5.41), but significant in children (23% affected; RR 1.90, 99% CI 1.16 to 3.11). Levetiracetam had a positive effect on some aspects of cognition and QoL in adults and worsened certain aspects of child behaviour. Overall, this review update finds that in both adults and children with drug-resistant focal epilepsy, levetiracetam added on to usual care is more effective than placebo at reducing seizure frequency, it is unlikely to be stopped by patients, and it has minimal adverse effects outside of potential worsening behaviour in children. These findings are unchanged from the previous review update in 2012. This review update contributes two key additional findings: 1. a 500 mg daily dose of levetiracetam is no more effective than placebo at reducing seizures; and 2. the odds of response (50% reduction in seizure frequency) are increased by nearly 40% for each 1000 mg increase in dose of levetiracetam. It seems reasonable to continue the use of levetiracetam in both adults and children with drug-resistant focal epilepsy.

  • Research Article
  • Cite Count Icon 17
  • 10.3171/2022.7.peds2281
Responsive neurostimulation device therapy in pediatric patients with complex medically refractory epilepsy.
  • Nov 1, 2022
  • Journal of Neurosurgery: Pediatrics
  • Sara M Hartnett + 9 more

Pediatric epilepsy is characterized as drug resistant in 20%-30% of patients and defined as persistent seizures despite adequate treatment with two first-line antiepileptic medications. The American Academy of Neurology advocates surgical options earlier in the treatment of epilepsy to provide long-term seizure reduction. The new development of minimally invasive approaches has recently allowed for surgical options to patients not previously deemed surgical candidates. These may include patients with bilateral, deep, eloquent, or poorly localizing epileptogenic foci. To this end, responsive neurostimulation (RNS) is an FDA-approved closed-loop neuromodulation device for adjuvant treatment of adults with medically intractable epilepsy arising from one or multiple foci. In this study, the authors describe their initial institutional experience with the use of RNS in pediatric patients with drug-resistant epilepsy. An IRB-approved retrospective review was conducted of 8 pediatric patients who underwent RNS implantation at Cincinnati Children's Hospital Medical Center between 2019 and 2021. Eight patients met the inclusion criteria for the study. The average age at the time of surgery was 14.7 years (range 8-18 years) with a mean follow-up of 16.5 months. All patients underwent invasive monitoring with stereo-EEG, subdural grid placement, or a combination of both. All patients had either bilateral or eloquent cortex targets. Trajectories were based on noninvasive (phase 1) and invasive (phase 2) seizure onset zone localization data. Four (50%) of the 8 patients underwent surgical intervention for epilepsy prior to RNS placement. RNS electrodes were placed with robot-assisted guidance in a hybrid operating room with intraoperative CT and electrocorticography. The authors demonstrated individualized RNS electrode trajectory and placement with targets in the amygdala/hippocampus, bilateral insula, bilateral parietal and occipital targets, and frontoparietal regions for a total of 14 implanted electrodes. One adverse event occurred, a wound infection requiring return to the operating room for removal of the RNS implant. All patients demonstrated a reduction in seizure frequency. All patients achieved > 50% reduction in seizure frequency at last follow-up. RNS implantation in carefully selected pediatric patients appears safe and efficacious in reducing seizure burden with a low rate of operative complications.

  • Research Article
  • Cite Count Icon 17
  • 10.1002/14651858.cd007302.pub3
Vigabatrin add-on therapy for drug-resistant focal epilepsy.
  • Jul 30, 2020
  • Cochrane Database of Systematic Reviews
  • Rebecca Bresnahan + 4 more

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.

  • Research Article
  • Cite Count Icon 11
  • 10.1002/14651858.cd012433.pub2
Oxcarbazepine add-on for drug-resistant focal epilepsy.
  • Mar 4, 2020
  • Cochrane Database of Systematic Reviews
  • Rebecca Bresnahan + 2 more

Epilepsy is a common neurological disorder. In approximately 30% of epilepsy cases, seizures are uncontrolled by one antiepileptic drug (AED). These people require treatment with a combination of multiple AEDs and are described as having drug-resistant epilepsy. Oxcarbazepine is a keto-analogue of carbamazepine, an established AED, and can be used as an add-on treatment for drug-resistant epilepsy. To assess the efficacy and tolerability of oxcarbazepine as an add-on treatment for people with drug-resistant focal epilepsy. The following databases were searched on 24 September 2018: Cochrane Register of Studies (CRS Web), which includes the Cochrane Epilepsy Group Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL); Medline (Ovid) 1946 to 21 September 2018; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). Originally, we also searched SCOPUS as a substitute for Embase, but this is no longer necessary, because randomised and quasi-randomised controlled trials in Embase are now included in CENTRAL. Randomised controlled trials with parallel-group or cross-over design, recruiting people of any age with drug-resistant focal epilepsy. We accepted any level of blinding and trials could be placebo- or active-controlled. In accordance with the methodological procedures expected by the Cochrane Collaboration, two review authors independently assessed trial eligibility before extracting data and assessing risk of bias. We assessed the primary outcomes: median percentage seizure reduction per 28 days; 50% or greater reduction in seizure frequency; and adverse effects including ataxia, hyponatraemia, and somnolence. We assessed the secondary outcomes: seizure freedom; treatment withdrawal; cognitive effects; and quality of life. We used an intention-to-treat population for all primary analyses. We present results as risk ratios (RR) with 95% confidence intervals (CI), with the exception of adverse effects which we present with 99% CI. We identified six eligible studies, involving 1593 participants. We judged that three studies were at unclear risk of bias and three were at high risk of bias. Bias mainly arose from lack of methodological details and from high attrition rates. Participants were aged 1 month to 65 years, with a diagnosis of drug-resistant focal epilepsy. All studies were either placebo- or alternative-dose-controlled with parallel-group design. The treatment period varied from 9 days to 26 weeks. The median percentage seizure reduction per 28 days (3 studies; moderate-certainty evidence) ranged from 26% to 83.3% for participants randomised to experimental oxcarbazepine compared to 7.6% to 28.7% for participants randomised to control treatment. Oxcarbazepine may increase the responder rate for 50% or greater reduction in seizure frequency compared to control treatment (RR 1.80, 95% CI 1.27 to 2.56; random-effects model; 6 studies; low-certainty evidence). For seizure freedom, the RR was 2.86 (95% CI 1.19 to 6.87; random-effects model; 5 studies; low-certainty evidence), suggesting an advantageous effectiveness of oxcarbazepine over control treatment. Treatment with oxcarbazepine was associated with an increased treatment withdrawal rate compared to control (RR 1.75, 95% CI 1.44 to 2.13; fixed-effect model; 6 studies; moderate-certainty evidence). The largest oxcarbazepine dose used, 2400 mg/d, was associated with a higher treatment withdrawal rate (RR 2.38, 95% CI 1.92 to 2.94; fixed-effect model; 2 studies) compared to control, than 1200 mg/d (RR 1.54, 95% CI 1.21 to 1.95; fixed-effect model; 3 studies) or 600 mg/d oxcarbazepine (RR 0.79, 95% CI 0.55 to 1.15; fixed-effect model; 1 study). Treatment with oxcarbazepine was associated with an increased incidence of multiple adverse effects including: ataxia (RR 2.54, 99% CI 0.86 to 7.54; random-effects model; 5 studies; moderate-certainty evidence); and somnolence (RR 2.03, 99% CI 1.17 to 3.54; random-effects model; 6 studies; low-certainty evidence). Hyponatraemia occurred more frequently with oxcarbazepine treatment but not significantly so (RR 2.53, 99% CI 0.27 to 23.85; fixed-effect model; 6 studies; moderate-certainty evidence). Oxcarbazepine might be effective at reducing seizure frequency when used as an add-on for drug-resistant focal epilepsy. The efficacy outcomes - 50% or greater seizure reduction and seizure freedom - were derived from low-certainty evidence. We are, therefore, uncertain whether the estimated effect size is representative of the true effect. In contrast, the evidence for median percentage seizure reduction and treatment withdrawal were of moderate certainty: thus, we are fairly certain of the effect estimates' reliability. Overall, we are unsure of the true efficacy of oxcarbazepine, but have concerns about its tolerability.

  • Research Article
  • Cite Count Icon 61
  • 10.1002/14651858.cd001416.pub3
Zonisamide add-on for drug-resistant partial epilepsy.
  • Dec 19, 2013
  • The Cochrane database of systematic reviews
  • Katie Carmichael + 4 more

The majority of people with epilepsy have a good prognosis and their seizures can be well controlled with the use of a single antiepileptic agent, but up to 30% develop refractory epilepsy, especially those with partial seizures. In this review we summarise the current evidence regarding zonisamide, when used as an add-on treatment for drug-resistant partial epilepsy. To evaluate the efficacy and tolerability of zonisamide when used as an add-on treatment for people with drug-resistant partial epilepsy. We searched the Cochrane Epilepsy Group Specialized Register (12 February 2013), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 1) (January 2013), MEDLINE (Ovid, 1946 to 12 February 2013), SCOPUS (13 February 2013), ClinicalTrials.gov (12 February 2013) and the WHO International Clinical Trials Registry Platform ICTRP (13 February 2013). In addition, we contacted Eisai Limited (makers and licensees of zonisamide) and experts in the field to seek any ongoing/unpublished studies. Randomised, placebo-controlled, add-on trials of zonisamide in people with drug-resistant partial epilepsy. Two review authors independently selected trials for inclusion and extracted data. Outcomes were: (1) 50% or greater reduction in total seizure frequency; (2) treatment withdrawal; (3) adverse effects. Primary analyses were intention-to-treat. We estimated summary risk ratios (RRs) for each outcome. All studies were assessed for risk of bias using the Cochrane risk of bias tool and the quality of evidence was assessed using the GRADE approach and presented in a summary of findings table. Five trials (949 participants) were included. The overall RR with 95% confidence interval (CI) for 50% reduction in seizure frequency compared to placebo for 300 to 500 mg/day of zonisamide was 2.00 (95% CI 1.58 to 2.54). The RR for 50% reduction in seizure frequency compared to placebo for any dose of zonisamide (100 to 500 mg per day) was 1.92 (95% CI 1.52 to 2.42). The number needed to treat (NNT) was 6 for this outcome. Two trials provide evidence of a dose response relationship for this outcome. The RR for treatment withdrawal for 300 to 500 mg/day of zonisamide compared to placebo was 1.64 (95% CI 1.20 to 2.25) and for 100 to 500 mg per day was 1.47 (95% CI 1.07 to 2.01). NNT for this outcome was 21. The CIs of the following adverse effects indicate that they are significantly associated with zonisamide: ataxia 3.77 (99% CI 1.28 to 11.11); somnolence 1.83 (99% CI 1.08 to 3.11); agitation 2.35 (99% CI 1.05 to 5.27) and anorexia 2.71 (99% CI 1.29 to 5.69). Across the 5 studies, risk of bias domains were rated as low is bias or unclear. None of the evidence for outcomes was downgraded for quality. Zonisamide has efficacy as an add-on treatment in people with drug-resistant partial epilepsy. In this review minimum effective and maximum tolerated doses cannot be identified. The trials reviewed were of a maximum stable-dose phase of 18 weeks in duration and results cannot be used to confirm longer periods of effectiveness in seizure control. The results cannot be extrapolated to monotherapy or to people with other seizure types or epilepsy syndromes.

  • Supplementary Content
  • Cite Count Icon 43
  • 10.3389/fphar.2023.1192022
Fenfluramine: a plethora of mechanisms?
  • May 12, 2023
  • Frontiers in Pharmacology
  • Jo Sourbron + 1 more

Developmental and epileptic encephalopathies are rare, treatment-resistant epilepsies with high seizure burden and non-seizure comorbidities. The antiseizure medication (ASM) fenfluramine is an effective treatment for reducing seizure frequency, ameliorating comorbidities, and potentially reducing risk of sudden unexpected death in epilepsy (SUDEP) in patients with Dravet syndrome and Lennox-Gastaut syndrome, among other rare epilepsies. Fenfluramine has a unique mechanism of action (MOA) among ASMs. Its primary MOA is currently described as dual-action sigma-1 receptor and serotonergic activity; however, other mechanisms may be involved. Here, we conduct an extensive review of the literature to identify all previously described mechanisms for fenfluramine. We also consider how these mechanisms may play a role in the reports of clinical benefit in non-seizure outcomes, including SUDEP and everyday executive function. Our review highlights the importance of serotonin and sigma-1 receptor mechanisms in maintaining a balance between excitatory (glutamatergic) and inhibitory (γ-aminobutyric acid [GABA]-ergic) neural networks, and suggests that these mechanisms may represent primary pharmacological MOAs in seizures, non-seizure comorbidities, and SUDEP. We also describe ancillary roles for GABA neurotransmission, noradrenergic neurotransmission, and the endocrine system (especially such progesterone derivatives as neuroactive steroids). Dopaminergic activity underlies appetite reduction, a common side effect with fenfluramine treatment, but any involvement in seizure reduction remains speculative. Further research is underway to evaluate promising new biological pathways for fenfluramine. A better understanding of the pharmacological mechanisms for fenfluramine in reducing seizure burden and non-seizure comorbidities may allow for rational drug design and/or improved clinical decision-making when prescribing multi-ASM regimens.

  • Research Article
  • Cite Count Icon 6
  • 10.1111/epi.17583
The need for an individualized approach to what is considered a clinically significant reduction in seizure frequency: A patient's perspective.
  • Mar 20, 2023
  • Epilepsia
  • Mia L Van Der Kop

The need for an individualized approach to what is considered a clinically significant reduction in seizure frequency: A patient's perspective.

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