Polyunsaturated fatty acids and epilepsy

Towards a better understanding of idiopathic epilepsy through metabolic fingerprinting of cerebrospinal fluid in dogs

Cerebrospinal fluid metabolomics is a promising research technology in the elucidation of nervous system disorders. Therefore, in this work, a cerebrospinal fluid (CSF) metabolomics method using liquid chromatography coupled to mass spectrometry was optimized and validated to cover a wide range of metabolites. An acceptable coefficient of variance regarding instrumental, within-lab and intra-assay precision was found for 95, 70 and 96 of 102 targeted metabolites, together with 1256, 676 and 976 untargeted compounds, respectively. Moreover, approximately 75% of targeted metabolites and 50% of untargeted compounds displayed good linearity across different dilution ranges. Consequently, metabolic alterations in CSF of dogs with idiopathic epilepsy (IE) were studied by comparing CSF of dogs diagnosed with IE (Tier II) to dogs with non-brain related disease. Targeted metabolome analysis revealed higher levels of cortisol, creatinine, glucose, hippuric acid, mannose, pantothenol, and 2-phenylethylamine (P values < 0.05) in CSF of dogs with IE, whereas CSF of dogs with IE showed lower levels of spermidine (P value = 0.02). Untargeted CSF metabolic fingerprints discriminated dogs with IE from dogs with non-brain related disease using Orthogonal Partial Least Squares Discriminant Analysis (R2(Y) = 0.997, Q2(Y) = 0.828), from which norepinephrine was putatively identified as an important discriminative metabolite.

Oleaginous Microbial Lipids' Potential in the Prevention and Treatment of Neurological Disorders

The products of oleaginous microbes, primarily lipids, have gained tremendous attention for their health benefits in food-based applications as supplements. However, this emerging biotechnology also offers a neuroprotective treatment/management potential for various diseases that are seldom discussed. Essential fatty acids, such as DHA, are known to make up the majority of brain phospholipid membranes and are integral to cognitive function, which forms an important defense against Alzheimer's disease. Omega-3 polyunsaturated fatty acids have also been shown to reduce recurrent epilepsy seizures and have been used in brain cancer therapies. The ratio of omega-3 to omega-6 PUFAs is essential in maintaining physiological function. Furthermore, lipids have also been employed as an effective vehicle to deliver drugs for the treatment of diseases. Lipid nanoparticle technology, used in pharmaceuticals and cosmeceuticals, has recently emerged as a biocompatible, biodegradable, low-toxicity, and high-stability means for drug delivery to address the drawbacks associated with traditional medicine delivery methods. This review aims to highlight the dual benefit that lipids offer in maintaining good health for disease prevention and in the treatment of neurological diseases.

Dietary Supplementation with Milk Lipids Leads to Suppression of Developmental and Behavioral Phenotypes of Hyperexcitable Drosophila Mutants

Dietary modifications often have a profound impact on the penetrance and expressivity of neurological phenotypes that are caused by genetic defects. Our previous studies in Drosophila melanogaster revealed that seizure-like phenotypes of gain-of-function voltage-gated sodium (Nav) channel mutants (paraShu, parabss1, and paraGEFS+), as well as other seizure-prone "bang-sensitive" mutants (eas and sda), were drastically suppressed by supplementation of a standard diet with milk whey. In the current study we sought to determine which components of milk whey are responsible for the diet-dependent suppression of their hyperexcitable phenotypes. Our systematic analysis reveals that supplementing the diet with a modest amount of milk lipids (0.26% w/v) mimics the effects of milk whey. We further found that a minor milk lipid component, α-linolenic acid, contributed to the diet-dependent suppression of adult paraShu phenotypes. Given that lipid supplementation during the larval stages effectively suppressed adult paraShu phenotypes, dietary lipids likely modify neural development to compensate for the defects caused by the mutations. Consistent with this notion, lipid feeding fully rescued abnormal dendrite development of class IV sensory neurons in paraShu larvae. Overall, our findings demonstrate that milk lipids are sufficient to ameliorate hyperexcitable phenotypes in Drosophila mutants, providing a foundation for future investigation of the molecular and cellular mechanisms by which dietary lipids modify genetically induced abnormalities in neural development, physiology, and behavior.

The effects of ketogenic diet on beta-hydroxybutyrate, arachidonic acid, and oxidative stress in pediatric epilepsy

The exact mechanism of a ketogenic diet (KD) as a suitable alternative therapeutic approach for drug-resistant epilepsy (DRE) in alleviating seizures is not yet fully understood. The present study aimed to evaluate the role of the KD in reducing oxidative stress (OS) by increasing the ketone body beta-hydroxybutyrate (BHB) and Arachidonic acid (ARA), an essential polyunsaturated fatty acid, as a possible mechanism in relieving seizure attacks in children with DRE. Forty children with refractory epilepsy were included in the present study. The serum levels of BHB, ARA, and OS markers, malondialdehyde (MDA), and 8-hydroxyl-deoxyguanosine (8-OHdG), were evaluated in children with DRE and compared before and after the three months of KD therapy. Thirty-four of 40 included children could complete the three-month KD therapy. Twenty-one (61.76%) patients had more than a 50% reduction in seizure frequency after the KD (responders). The remaining 13 children were considered non-responders to the diet. The serum levels of ARA and BHB significantly (p < 0.05) increased after the KD therapy. The serum levels of OS parameters MDA and 8-OHdG before the diet therapy were significantly (p < 0.05) higher than those after the administration. The serum levels of BHB and MDA after the KD therapy in the responders were respectively higher and lower than those in the non-responders (p < 0.001). Ketogenic diet might reduce brain OS by increasing BHB and ARA. The role of BHB in diminishing OS and seizure might be more remarkable than ARA.

Integrating metabolomics and lipidomics revealed a decrease in plasma fatty acids but an increase in triglycerides in children with drug-refractory epilepsy

OBJECTIVE

The drug-refractory epilepsy (DRE) in children is commonly observed but the underlying mechanisms remain elusive. We examined whether fatty acids (FAs) and lipids are potentially associated with the pharmacoresistance to valproic acid (VPA) therapy.

METHODS

This single-center, retrospective cohort study was conducted using data from pediatric patients collected between May 2019 and December 2019 at the Children's Hospital of Nanjing Medical University. Ninety plasma samples from 53 responders with VPA monotherapy (RE group) and 37 non-responders with VPA polytherapy (NR group) were collected. Non-targeted metabolomics and lipidomics analysis for those plasma samples were performed to compare the potential differences of small metabolites and lipids between the two groups. Plasma metabolites and lipids passing the threshold of variable importance in projection value >1, fold change >1.2 or <0.8, and p-value <0.05 were regarded as statistically different substances.

RESULTS

A total of 204 small metabolites and 433 lipids comprising 16 different lipid subclasses were identified. The well-established partial least squares-discriminant analysis (PLS-DA) revealed a good separation of the RE from the NR group. The FAs and glycerophospholipids status were significantly decreased in the NR group, but their triglycerides (TG) levels were significantly increased. The trend of TG levels in routine laboratory tests was in line with the lipidomics analysis. Meanwhile, cases from the NR group were characterized by a decreased level of citric acid and L-thyroxine, but with an increased level of glucose and 2-oxoglutarate. The top two enriched metabolic pathways involved in the DRE condition were biosynthesis of unsaturated FAs and linoleic acid metabolism.

SIGNIFICANCE

The results of this study suggested an association between metabolism of FAs and the medically intractable epilepsy. Such novel findings might propose a potential mechanism linked to the energy metabolism. Ketogenic acid and FAs supplementation might therefore be high-priority strategies for DRE management.

Is the peroxisome proliferator-activated receptor gamma a putative target for epilepsy treatment? Current evidence and future perspectives

The peroxisome proliferator-activated receptor gamma (PPARγ), which belongs to the family of nuclear receptors, has been mainly studied as an important factor in metabolic disorders. However, in recent years the potential role of PPARγ in different neurological diseases has been increasingly investigated. Especially, in the search of therapeutic targets for patients with epilepsy the question of the involvement of PPARγ in seizure control has been raised. Epilepsy is a chronic neurological disorder causing a major impact on the psychological, social, and economic conditions of patients and their families, besides the problems of the disease itself. Considering that the world prevalence of epilepsy ranges between 0.5% - 1.0%, this condition is the fourth for importance among the other neurological disorders, following migraine, stroke, and dementia. Among others, temporal lobe epilepsy (TLE) is the most common form of epilepsy in adult patients. About 65% of individuals who receive antiseizure medications (ASMs) experience seizure independence. For those in whom seizures still recur, investigating PPARγ could lead to the development of novel ASMs. This review focuses on the most important findings from recent investigations about the potential intracellular PPARγ-dependent processes behind different compounds that exhibited anti-seizure effects. Additionally, recent clinical investigations are discussed along with the promising results found for PPARγ agonists and the ketogenic diet (KD) in various rodent models of epilepsy.

The role of nutrition in canine idiopathic epilepsy management: Fact or fiction?

In the last decade, nutrition has gained interest in the management of canine idiopathic epilepsy (IE) based on growing scientific evidence. Diets can serve their functions through many pathways. One potential pathway includes the microbiota-gut-brain axis, which highlights the relationship between the brain and the intestines. Changing the brain's energy source and a number of dietary sourced anti-inflammatory and neuroprotective factors appears to be the basis for improved outcomes in IE. Selecting a diet with anti-seizure effects and avoiding risks of proconvulsant mediators as well as interference with anti-seizure drugs should all be considered in canine IE. This literature review provides information about preclinical and clinical evidence, including a systematic evaluation of the level of evidence, suggested mechanism of action and interaction with anti-seizure drugs as well as pros and cons of each potential dietary adaptation in canine IE.

Case report: Functional characterization of a de novo c.145G>A p.Val49Met pathogenic variant in a case of PIGA-CDG with megacolon

A subgroup of congenital disorders of glycosylation (CDGs) includes inherited GPI-anchor deficiencies (IGDs) that affect the biosynthesis of glycosylphosphatidylinositol (GPI) anchors, including the first reaction catalyzed by the X-linked PIGA. Here, we show the first PIGA-CDG case reported in Mexico in a male child with a moderate-to-severe phenotype characterized by neurological and gastrointestinal symptoms, including megacolon. Exome sequencing identified the hemizygous variant PIGA c.145G>A (p.Val49Met), confirmed by Sanger sequencing and characterized as de novo. The pathogenicity of this variant was characterized by flow cytometry and complementation assays in PIGA knockout (KO) cells.

Sacha Inchi (Plukenetia Volubilis L.): recent insight on phytochemistry, pharmacology, organoleptic, safety and toxicity perspectives

Sacha Inchi (Plukenetia Volubilis L.), SI, is the oleaginous plant of the Euphorbiaceous family originally cultivated in the Amazonian forest. It is traditionally appreciated and consumed as the healthful food. In vivo, in vitro and clinical studies have suggested the beneficial effects of SI for a variety of neuroprotection, dermatology, antidyslipidaemic, antioxidant and anti-inflammatory, antiproliferative and antitumor modulation activities. Many of these potential impacts are related to its bioactive compounds, particularly essential fatty acids, proteins and phytochemicals. However, there are some scientific evidences underlying the risk of toxicity associated with the high doses of SI seed oils. With the aforementioned, this review outlines a narrative review of SI, including its ethnobotanical components, phytochemistry profile, organoleptic and sensory evaluations. The essential development of its latest applications in the field of medicine, pharmacology, safety and toxicological issues, are laconically demonstrated. Moreover, the underlying challenges and upcoming prospective for the integration of SI use are detailed.

Interactions between the gut microbiome and ketogenic diet in refractory epilepsy

Epilepsy is one of the most common neurological diseases globally, afflicting approximately 50 million people worldwide. While many antiepileptic drugs exist, an estimated one-third of individuals do not respond to available medications. The high fat, low carbohydrate ketogenic diet (KD) has been used to treat refractory epilepsy in cases when existing antiepileptic drugs fail. However, there are many variations of the KD, each of which varies greatly in its efficacy and side effects. Increasing evidence suggests that interactions between the KD and gut microbiome may modulate the effects of the diet on host physiology. Herein, we review existing evidence of microbiome differences in epileptic individuals compared to healthy controls. We highlight in particular both clinical and animal studies revealing effects of the KD on the composition and function of the microbiome, as well as proof-of-concept animal studies that implicate the microbiome in the antiseizure effects of the KD. We further synthesize findings suggesting that variations in clinical KD formulations may differentially influence host physiology and discuss the gut microbial interactions with specific dietary factors that may play a role. Overall, understanding interactions between the gut microbiota and specific nutritional components of clinical KDs could reveal foundational mechanisms that underlie the effectiveness, variability, and side effects of different KDs, with the potential to lead to precision nutritional and microbiome-based approaches to treat refractory epilepsy.

Ketogenic and Modified Mediterranean Diet as a Tool to Counteract Neuroinflammation in Multiple Sclerosis: Nutritional Suggestions

Ketogenic Diet is a nutritional pattern often used as dietotherapy in inflammatory diseases, including neurological disorders. Applied on epileptic children since 1920, in recent years it has been taken into account again as a tool to both reduce inflammatory burdens and ameliorate the nutritional status of patients affected by different pathologies. Multiple sclerosis (MS) is considered an immune-mediated neuro-inflammatory disease and diet is a possible factor in its pathogenesis. The aim of this work is to investigate the main potential targets of MS-related impairments, in particular the cognitive deficits, focusing on the alteration of biomarkers such as the Brain Derived-Neurotrophic Factor and the Tryptophan/Kynurenine ratio that could play a role on neuroprotection and thus on MS progression. Furthermore, we here propose nutritional suggestions which are useful in the development of a ketogenic diet protocol that takes advantage of the anti-inflammatory properties of low-carbohydrate foods from the Mediterranean diet to be applied to subjects with MS. In conclusion, this approach will allow one to develop the ketogenic diet combined with a modified Mediterranean diet as a possible tool to improve neuroinflammation in multiple sclerosis.

Nutrition interventions in congenital disorders of glycosylation

Congenital disorders of glycosylation (CDG) are a group of more than 160 inborn errors of metabolism affecting multiple pathways of protein and lipid glycosylation. Patients present with a wide range of symptoms and therapies are only available for very few subtypes. Specific nutritional treatment options for certain CDG types include oral supplementation of monosaccharide sugars, manganese, uridine, or pyridoxine. Additional management includes specific diets (i.e., complex carbohydrate or ketogenic diet), iron supplementation, and albumin infusions. We review the dietary management in CDG with a focus on two subgroups: N-linked glycosylation defects and GPI-anchor disorders.

Efficacy of the Ketogenic Diet for Pediatric Epilepsy According to the Presence of Detectable Somatic mTOR Pathway Mutations in the Brain

Background and Purpose

A multifactorial antiepileptic mechanism underlies the ketogenic diet (KD), and one of the proposed mechanisms of action is that the KD inhibits the mammalian target of rapamycin (mTOR) pathway. To test this clinically, this study aimed to determine the efficacy of the KD in patients with pathologically confirmed focal cortical dysplasia (FCD) due to genetically identifiable mTOR pathway dysregulation.

Methods

A cohort of patients with pathologically confirmed FCD after epilepsy surgery and who were screened for the presence of germline and somatic mutations related to the mTOR pathway in peripheral blood and resected brain tissue was constructed prospectively. A retrospective review of the efficacy of the prior KD in these patients was performed.

Results

Twenty-five patients with pathologically confirmed FCD and who were screened for the presence of detectable somatic mTOR pathway mutations had received a sufficient KD. Twelve of these patients (48.0%) had germline or somatic detectable mTOR pathway mutations. A response was defined as a ≥50% reduction in seizure frequency. The efficacy of the KD after 3 months of dietary therapy was superior in patients with detectable mTOR pathway mutations than in patients without detectable mTOR pathway mutations, although the difference was not statistically significant (responder rates of 58.3% vs. 38.5%, p=0.434).

Conclusions

A greater proportion of patients with mTOR pathway responded to the KD, but there was no statistically significant difference in efficacy of the KD between patients with and without detectable mTOR pathway mutations. Further study is warranted due to the smallness of the sample and the limited number of mTOR pathway genes tested in this study.

New Trends and Most Promising Therapeutic Strategies for Epilepsy Treatment

Background: Despite the wide availability of novel anti-seizure medications (ASMs), 30% of patients with epilepsy retain persistent seizures with a significant burden in comorbidity and an increased risk of premature death. This review aims to discuss the therapeutic strategies, both pharmacological and non-, which are currently in the pipeline.

Methods: PubMed, Scopus, and EMBASE databases were screened for experimental and clinical studies, meta-analysis, and structured reviews published between January 2018 and September 2021. The terms “epilepsy,” “treatment” or “therapy,” and “novel” were used to filter the results.

Conclusions: The common feature linking all the novel therapeutic approaches is the spasmodic rush toward precision medicine, aiming at holistically evaluating patients, and treating them accordingly as a whole. Toward this goal, different forms of intervention may be embraced, starting from the choice of the most suitable drug according to the type of epilepsy of an individual or expected adverse effects, to the outstanding field of gene therapy. Moreover, innovative insights come from in-vitro and in-vivo studies on the role of inflammation and stem cells in the brain. Further studies on both efficacy and safety are needed, with the challenge to mature evidence into reliable assets, ameliorating the symptoms of patients, and answering the challenges of this disease.

Practical Considerations for Ketogenic Diet in Adults With Super-Refractory Status Epilepticus

Purpose of Review

Ketogenic diet therapy can be used as an adjuvant treatment of super-refractory status epilepticus (SRSE). However, the drug and metabolic interactions with concomitant treatments present a challenge for clinicians. In this review, we focus on the practical considerations of implementing ketogenic dietary therapy in the acute setting, including the dietary composition, potential drug-diet interactions, and monitoring during ketogenic treatment.

Recent Findings

This report describes the ketogenic diet therapy protocol implemented for the treatment of SRSE and a review of the current evidence to support clinical practice.

Summary

The control of SRSE is critical in reducing morbidity and mortality. There is emerging evidence that ketogenic diet may be a safe and effective treatment option for these patients.

Microbiota-Gut-Brain Axis and Epilepsy: A Review on Mechanisms and Potential Therapeutics

The gut-brain axis refers to the bidirectional communication between the gut and brain, and regulates intestinal homeostasis and the central nervous system via neural networks and neuroendocrine, immune, and inflammatory pathways. The development of sequencing technology has evidenced the key regulatory role of the gut microbiota in several neurological disorders, including Parkinson's disease, Alzheimer's disease, and multiple sclerosis. Epilepsy is a complex disease with multiple risk factors that affect more than 50 million people worldwide; nearly 30% of patients with epilepsy cannot be controlled with drugs. Interestingly, patients with inflammatory bowel disease are more susceptible to epilepsy, and a ketogenic diet is an effective treatment for patients with intractable epilepsy. Based on these clinical facts, the role of the microbiome and the gut-brain axis in epilepsy cannot be ignored. In this review, we discuss the relationship between the gut microbiota and epilepsy, summarize the possible pathogenic mechanisms of epilepsy from the perspective of the microbiota gut-brain axis, and discuss novel therapies targeting the gut microbiota. A better understanding of the role of the microbiota in the gut-brain axis, especially the intestinal one, would help investigate the mechanism, diagnosis, prognosis evaluation, and treatment of intractable epilepsy.

The ω-3 endocannabinoid docosahexaenoyl ethanolamide reduces seizure susceptibility in mice by activating cannabinoid type 1 receptors

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are the most recognized omega-3 unsaturated fatty acids showing neuroprotective activity in animal and clinical studies. Docosahexaenoyl ethanolamide (DHEA) and eicosapentaenoyl ethanolamide (EPEA) are non-oxygenated endogenous metabolites of DHA and EPA, which might be in charge of the anti-seizure activity of the parent molecules. We examined the effect of these metabolites on the threshold of clonic seizures induced by pentylenetetrazole (PTZ). DHEA and EPEA possess similar chemical structure to the endogenous cannabinoids. Therefore, involvement of cannabinoid (CB) receptors in the anti-seizure effect of these metabolites was also investigated. DHA, DHEA, EPEA, AM251 (CB1 receptor antagonist), and AM630 (CB2 receptor antagonist) were administered to mice by intracerebroventricular (i.c.v.) route. Threshold of clonic seizures was determined 10 and/or 15 min thereafter by intravenous infusion of PTZ. The effect of DHA and DHEA on seizure threshold was then determined in mice, which were pretreated with AM251 and/or AM630. DHA (300μM), and DHEA (100 and 300 μM) significantly increased seizure threshold, 15 (p < 0.05) and 10 min (p < 0.01) after administration, respectively. DHEA was more potent than its parent lipid, DHA in decreasing seizure susceptibility. EPEA (300 and 1000 μM) did not change seizure threshold. AM251 fully prevented the increasing effect of DHA and DHEA on seizure threshold (p < 0.05). AM630 did not inhibit the effect of DHA and DHEA on seizure threshold. This is the first report indicating that DHEA but not EPEA, possesses anti-seizure action via activating CB1 receptors. DHEA is more potent than its parent ω-3 fatty acid DHA in diminishing seizure susceptibility.

Anticonvulsant mechanisms of the ketogenic diet and caloric restriction

Many treatments have been proposed to control epileptic seizures, such as the ketogenic diet and caloric restriction. However, seizure control has not yet been improved completely in all patients. Probably, due to the lack of understanding regarding this neurological disorder pathogenesis or pathophysiology, including its molecular approach. Currently, there is not much information about the molecular processes and genes involved, and their relation to the possible beneficial effects of diet therapy on epilepsy. The ketogenic diet and caloric restriction are implicated in potential anti-seizure mechanisms related to the gut microbiome, metabolic pathways, hormones and neurotransmitters, mitochondria improvement, a role in inflammation, and oxidative stress, among others. In this review, we pretend to describe the molecular mechanism and the possible genes involved in the different ketogenic diet and caloric restriction mechanisms of action described to decrease neural excitability and, therefore, epileptic seizures, especially when conventional treatment is not enough to achieve control of epilepsy.

Seizure-induced impairment in neuronal ketogenesis: Role of zinc-α2-glycoprotein in mitochondria

Ketone bodies (KBs) were known to suppress seizure. Untraditionally, neurons were recently reported to utilize fatty acids and produce KBs, but the effect of seizure on neuronal ketogenesis has not been researched. Zinc‐α2‐glycoprotein (ZAG) was reported to suppress seizure via unclear mechanism. Interestingly, ZAG was involved in fatty acid β‐oxidation and thus may exert anti‐epileptic effect by promoting ketogenesis. However, this promotive effect of ZAG on neuronal ketogenesis has not been clarified. In this study, we performed immunoprecipitation and mass spectrometry to identify potential interaction partners with ZAG. The mechanisms of how ZAG translocated into mitochondria were determined by quantitative coimmunoprecipitation after treatment with apoptozole, a heat shock cognate protein 70 (HSC70) inhibitor. ZAG level was modulated by lentivirus in neurons or adeno‐associated virus in rat brains. Seizure models were induced by magnesium (Mg²⁺)‐free artificial cerebrospinal fluid in neurons or intraperitoneal injection of pentylenetetrazole kindling in rats. Ketogenesis was determined by cyclic thio‐NADH method in supernatant of neurons or brain homogenate. The effect of peroxisome proliferator–activated receptor γ (PPARγ) on ZAG expression was examined by Western blot, quantitative real‐time polymerase chain reaction (qRT‐PCR) and chromatin immunoprecipitation qRT‐PCR. We found that seizure induced ketogenesis deficiency via a ZAG‐dependent mechanism. ZAG entered mitochondria through a HSC70‐dependent mechanism, promoted ketogenesis by binding to four β‐subunits of long‐chain L‐3‐hydroxyacyl‐CoA dehydrogenase (HADHB) and alleviated ketogenesis impairment in a neuronal seizure model and pentylenetetrazole‐kindled epileptic rats. Additionally, PPARγ activation up‐regulated ZAG expression by binding to promoter region of AZGP1 gene and promoted ketogenesis through a ZAG‐dependent mechanism.

A Switch to Polyunsaturated Fatty Acid Based Ketogenic Diet Improves Seizure Control in Patients with Drug-resistant Epilepsy on the Mixed Fat Ketogenic Diet: A Retrospective Open Label Trial

Introduction

The ketogenic diet (KD) is used for drug-resistant epilepsy. However, some patients find only a modest benefit, which may plateau over time. Evidence from several animal and human studies suggests that polyunsaturated fatty acids (PUFAs) may be a beneficial form of treatment for these patients. This retrospective study was conducted to evaluate whether a switch from classic mixed fats KD (MFKD) to a natural polyunsaturated fatty acid KD (PUFA-KD) would improve seizure control.

Methods

The study evaluated the medical paper record forms of patients who had at least one seizure per week despite the use of MFKD. These patients were started on PUFA-KD and grouped according to the oils preferred. We analyzed the effect on seizure control, tolerability, blood lipids, and adverse effects and whether the type of seizures, age of seizure onset, age at which KD was started, and the ratio of omega 6: omega 3 (n6:n3) fatty acids had any effect on seizure control.

Results

Data from fifty patients (aged 10 months to 35 years) were analyzed. At the end of six and 12 months on the PUFA-KD, 12% (6) and 16% (8) were seizure-free and 82% (41) and 88% (44) had a >50% reduction in seizures, respectively. The mean seizure control at 12 months was highest in patients with mixed seizures followed by those with generalized seizures and lowest for those with focal seizures. Seizure control at 12 months was inversely correlated to the age of onset of epilepsy and age at initiation of KD. This improvement was independent of the type of PUFAs and the ratio of n6:n3 used. The PUFA-KD was generally well tolerated. Blood lipid levels significantly improved.

Conclusion

Changing to PUFA-KD improved seizure control in patients who did not respond satisfactorily to MFKD.

n-3 Docosapentaenoic acid-derived protectin D1 promotes resolution of neuroinflammation and arrests epileptogenesis

Epilepsy therapy is based on drugs that treat the symptoms rather than the underlying mechanisms of the disease (epileptogenesis). There are no treatments for preventing seizures or improving disease prognosis, including neurological comorbidities. The search of pathogenic mechanisms of epileptogenesis highlighted that neuroinflammatory cytokines [i.e. interleukin-1β (IL-1β), tumour necrosis factor-α (Tnf-α)] are induced in human and experimental epilepsies, and contribute to seizure generation in animal models. A major role in controlling the inflammatory response is played by specialized pro-resolving lipid mediators acting on specific G-protein coupled receptors. Of note, the role that these pathways have in epileptogenic tissue remains largely unexplored. Using a murine model of epilepsy, we show that specialized pro-resolving mechanisms are activated by status epilepticus before the onset of spontaneous seizures, but with a marked delay as compared to the neuroinflammatory response. This was assessed by measuring the time course of mRNA levels of 5-lipoxygenase (Alox5) and 15-lipoxygenase (Alox15), the key biosynthetic enzymes of pro-resolving lipid mediators, versus Il1b and Tnfa transcripts and proteins. In the same hippocampal tissue, we found a similar delayed expression of two main pro-resolving receptors, the lipoxin A₄ receptor/formyl peptide receptor 2 and the chemerin receptor. These receptors were also induced in the human hippocampus after status epilepticus and in patients with temporal lobe epilepsy. This evidence supports the hypothesis that the neuroinflammatory response is sustained by a failure to engage pro-resolving mechanisms during epileptogenesis. Lipidomic LC-MS/MS analysis showed that lipid mediator levels apt to resolve the neuroinflammatory response were also significantly altered in the hippocampus during epileptogenesis with a shift in the biosynthesis of several pro-resolving mediator families including the n-3 docosapentaenoic acid (DPA)-derived protectin D1. Of note, intracerebroventricular injection of this mediator during epileptogenesis in mice dose-dependently reduced the hippocampal expression of both Il1b and Tnfa mRNAs. This effect was associated with marked improvement in mouse weight recovery and rescue of cognitive deficit in the novel object recognition test. Notably, the frequency of spontaneous seizures was drastically reduced by 2-fold on average and the average seizure duration was shortened by 40% after treatment discontinuation. As a result, the total time spent in seizures was reduced by 3-fold in mice treated with n-3 DPA-derived protectin D1. Taken together, the present findings demonstrate that epilepsy is characterized by an inadequate engagement of resolution pathways. Boosting endogenous resolution responses significantly improved disease outcomes, providing novel treatment avenues.

Functional Nutrients for Epilepsy

Epilepsy is a common neurological disorder of which seizures are a core symptom. Approximately one third of epileptic patients are resistant to antiepileptic drugs and therefore require alternative therapeutic options. Dietary and nutritional supplements can in some cases replace drugs, but with the exception of ketogenic diets, there are no officially recommended dietary considerations for patients with epilepsy. In this review we summarize a selection of nutritional suggestions that have proved beneficial in treating different types of epilepsy. We describe the types of seizures and epilepsy and follow this with an introduction to basic molecular mechanisms. We then examine several functional nutrients for which there is clinical evidence of therapeutic efficacy in reducing seizures or epilepsy-associated sudden death. We also discuss experimental results that demonstrate possible molecular mechanisms elicited by the administration of various nutrients. The availability of multiple dietary and nutritional candidates that show favorable outcomes in animals implies that assessing the clinical potential of these substances will improve translational medicine, ultimately benefitting epilepsy patients.

Dietary Omega-3 Polyunsaturated Fatty Acid Deprivation Does Not Alter Seizure Thresholds but May Prevent the Anti-seizure Effects of Injected Docosahexaenoic Acid in Rats

Background: Brain concentrations of omega-3 docosahexaenoic acid (DHA, 22:6n-3) have been reported to positively correlate with seizure thresholds in rodent seizure models. It is not known whether brain DHA depletion, achieved by chronic dietary omega-3 polyunsaturated fatty acid (PUFA) deficiency, lowers seizure thresholds in rats.

Objective: The present study tested the hypothesis that lowering brain DHA concentration with chronic dietary n-3 PUFA deprivation in rats will reduce seizure thresholds, and that compared to injected oleic acid (OA), injected DHA will raise seizure thresholds in rats maintained on n-3 PUFA adequate and deficient diets.

Methods: Rats (60 days old) were surgically implanted with electrodes in the amygdala, and subsequently randomized to the AIN-93G diet containing adequate levels of n-3 PUFA derived from soybean oil or an n-3 PUFA-deficient diet derived from coconut and safflower oil. The rats were maintained on the diets for 37 weeks. Afterdischarge seizure thresholds (ADTs) were measured every 4–6 weeks by electrically stimulating the amygdala. Between weeks 35 and 37, ADTs were assessed within 1 h of subcutaneous OA or DHA injection (600 mg/kg). Seizure thresholds were also measured in a parallel group of non-implanted rats subjected to the maximal pentylenetetrazol (PTZ, 110 mg/kg) seizure test. PUFA composition was measured in the pyriform-amygdala complex of another group of non-implanted rats sacrificed at 16 and 32 weeks.

Results: Dietary n-3 PUFA deprivation did not significantly alter amygdaloid seizure thresholds or latency to PTZ-induced seizures. Acute injection of OA did not alter amygdaloid ADTs of rats on the n-3 PUFA adequate or deficient diets, whereas acute injection of DHA significantly increased amygdaloid ADTs in rats on the n-3 PUFA adequate control diet as compared to rats on the n-3 PUFA deficient diet (P < 0.05). Pyriform-amygdala DHA percent composition did not significantly differ between the groups, while n-6 docosapentaenoic acid, a marker of n-3 PUFA deficiency, was significantly increased by 2.9-fold at 32 weeks.

Conclusion: Chronic dietary n-3 PUFA deficiency does not alter seizure thresholds in rats, but may prevent the anti-seizure effects of DHA.

The effect of omega-3 fatty acids on clinical and paraclinical features of intractable epileptic patients: a triple blind randomized clinical trial

Long chain omega-3 fatty acids (omega-3 FAs) supplements have been shown to exert beneficial effects in patients with epilepsy through elevation of seizure thresholds and dampening of inflammatory responses. In this triple blind randomized, placebo-controlled parallel group trial of omega-3 FA supplementation, 180 mg eicosapentaenoic acid (EPA) and 120 mg docosahexaenoic acid (DHA) as well as placebo capsules were administered twice a day in 50 patients with refractory seizure during a 16-week period respectively. Seizure frequency and duration were reduced after completion of the treatment in the supplement group. The supplementation resulted in a significant decrease in TNF-α and IL-6 concentrations. Further studies are needed to compare different omega-3 FA compositions and determine the most effective dose and treatment duration as well as the long term benefits of this supplementation.

Expression and Function of Zinc-α2-Glycoprotein

Zinc-α2-glycoprotein (ZAG), encoded by the AZGP1 gene, is a major histocompatibility complex I molecule and a lipid-mobilizing factor. ZAG has been demonstrated to promote lipid metabolism and glucose utilization, and to regulate insulin sensitivity. Apart from adipose tissue, skeletal muscle, liver, and kidney, ZAG also occurs in brain tissue, but its distribution in brain is debatable. Only a few studies have investigated ZAG in the brain. It has been found in the brains of patients with Krabbe disease and epilepsy, and in the cerebrospinal fluid of patients with Alzheimer disease, frontotemporal lobe dementia, and amyotrophic lateral sclerosis. Both ZAG protein and AZGP1 mRNA are decreased in epilepsy patients and animal models, while overexpression of ZAG suppresses seizure and epileptic discharges in animal models of epilepsy, but knowledge of the specific mechanism of ZAG in epilepsy is limited. In this review, we summarize the known roles and molecular mechanisms of ZAG in lipid metabolism and glucose metabolism, and in the regulation of insulin sensitivity, and discuss the possible mechanisms by which it suppresses epilepsy.

GPR40 modulates epileptic seizure and NMDA receptor function

Epilepsy is a common neurological disease, and approximately 30% of patients do not respond adequately to antiepileptic drug treatment. Recent studies suggest that G protein-coupled receptor 40 (GPR40) is expressed in the central nervous system and is involved in the regulation of neurological function. However, the impact of GPR40 on epileptic seizures remains unclear. In this study, we first reported that GPR40 expression was increased in epileptic brains. In the kainic acid-induced epilepsy model, GPR40 activation after status epilepticus alleviated epileptic activity, whereas GPR40 inhibition showed the opposite effect. In the pentylenetetrazole-induced kindling model, susceptibility to epilepsy was reduced with GPR40 activation and increased with GPR40 inhibition. Whole-cell patch-clamp recordings demonstrated that GPR40 affected N-methyl-d-aspartate (NMDA) receptor-mediated synaptic transmission. Moreover, GPR40 regulated NR2A and NR2B expression on the surface of neurons. In addition, endocytosis of NMDA receptors and binding of GPR40 with NR2A and NR2B can be regulated by GPR40. Together, our findings indicate that GPR40 modulates epileptic seizures, providing a novel antiepileptic target.

The differential effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on seizure frequency in patients with drug-resistant epilepsy - A randomized, double-blind, placebo-controlled trial

OBJECTIVES

The omega-3 (n-3) fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are known to play an important role in maintenance and modulation of neuronal functions. There is evidence that omega-3 fatty acids may have anticonvulsant effects. The effect of DHA and EPA on seizure rate in patients with drug-resistant epilepsy (DRE) was investigated.

METHODS

A double-blind, randomized, placebo-controlled clinical trial included ninety-nine (n = 99) subjects with DRE, aged 5-16 years (n = 85) and 17-45 years (n = 14). After randomization, subjects were given two, four, or six capsules per day of DHA (417.8 mg DHA and 50.8 mg EPA/capsule, n = 33), EPA (385.6 mg EPA and 81.2 mg DHA/capsule, n = 33), or placebo (high oleic acid sunflower oil, n = 33) for one year. The primary endpoint was the effect of treatment on rate of seizure. Random-effects negative binomial regression models were fitted to model the patients' total count of seizures per month. The treatment effects on seizure incidence rate ratio (IRR) were tested after controlling for the covariate effects of gender, age, rate of seizure per week at enrollment, type of seizure, and number of antiepileptic drug (AED) combinations used at enrollment.

RESULTS

Fifty-nine subjects (n = 59) completed the study (59.6%). The average number of seizures per month were 9.7 ± 1.2 in the EPA group, 11.7 ± 1.5 in the DHA group, and 16.6 ± 1.5 in the placebo group. Age, gender, and seizure-type adjusted seizure IRRs of the EPA and DHA groups compared with the placebo group were 0.61 (CI = 0.42-0.88, p = 0.008, 42% reduction) and 0.67 (CI = 0.46-1.0, p = 0.04, 39% reduction), respectively. There was no difference in IRR between the EPA and DHA groups (p = 0.56). Both treatment groups had a significantly higher number of seizure-free days compared with the placebo group (p < 0.05).

SIGNIFICANCE

This study demonstrates that EPA and DHA are effective in reducing seizure frequency in patients with DRE.

Investigating owner use of dietary supplements in dogs with idiopathic epilepsy

Epilepsy is the most common chronic neurological disorder in dogs. Some diets have been shown to have a positive impact upon the seizure activity in dogs with idiopathic epilepsy (IE), while other diets and dietary supplements (DS), although marketed as providing health benefits, lack conclusive scientific evidence on their actual beneficial effects. A web-based owner questionnaire was designed to assess how and why owners of dogs with IE use different dietary regimes and DS. The study cohort, with 297 valid responses, consisted mainly of pure-breed (82.5%) male neutered (52.9%) dogs. Over two-thirds of owners (67.7%) changed their dog's diet after their dog received a diagnosis of IE. Nearly half of the owners (45.8%) reported giving DS, the most common being coconut oil or derived medium-chain triglyceride oil (71.3%). Some owner justifications of DS use included improvement of seizure frequency (88.2%), seizure severity (61.8%) and protection from potential drug side effects (62.5%). Many owners give DS to their dog with IE. The pharmacokinetic properties of anti-epileptic drugs, such as efficacy, absorption and clearance can be influenced by other medications, diets and possibly by DS. We propose that use of DS should be considered and monitored by veterinary surgeons in epilepsy management.

The ketogenic diet is effective for refractory epilepsy associated with acquired structural epileptic encephalopathy

AIM

Ketogenic diet therapies have proven efficacy for refractory epilepsy. There are many reports of their use in the genetic developmental and epileptic encephalopathies; however, little attention has been paid as to whether the diet is also effective in individuals with an acquired structural aetiology. We observed remarkable efficacy of the diet in two patients with hypoxic-ischaemic encephalopathy. We then analysed our cases with refractory structural epilepsies of acquired origin to characterize their response to the ketogenic diet.

METHOD

The classical ketogenic diet was implemented with dietary ratios of 3:1 to 4.4:1. Seizure frequency at 1 month, 3 months, 6 months, 1 year, and 2 years was ascertained. A responder was defined as greater than 50% seizure reduction compared to baseline.

RESULTS

Seven of the nine patients were responders at 3 months.

INTERPRETATION

Somewhat surprisingly we found that the ketogenic diet was effective in patients with a developmental and epileptic encephalopathy due to an acquired structural aetiology. This cohort may not be routinely considered for the ketogenic diet because of their structural and acquired, rather than genetic, basis. The ketogenic diet should be considered early in the management of patients with acquired structural encephalopathies as it can improve seizure control with the potential to improve developmental outcome.

WHAT THIS PAPER ADDS

The ketogenic diet was effective in children with epilepsy associated with an acquired structural aetiology.

CDG Therapies: From Bench to Bedside

Congenital disorders of glycosylation (CDG) are a group of genetic disorders that affect protein and lipid glycosylation and glycosylphosphatidylinositol synthesis. More than 100 different disorders have been reported and the number is rapidly increasing. Since glycosylation is an essential post-translational process, patients present a large range of symptoms and variable phenotypes, from very mild to extremely severe. Only for few CDG, potentially curative therapies are being used, including dietary supplementation (e.g., galactose for PGM1-CDG, fucose for SLC35C1-CDG, Mn²⁺ for TMEM165-CDG or mannose for MPI-CDG) and organ transplantation (e.g., liver for MPI-CDG and heart for DOLK-CDG). However, for the majority of patients, only symptomatic and preventive treatments are in use. This constitutes a burden for patients, care-givers and ultimately the healthcare system. Innovative diagnostic approaches, in vitro and in vivo models and novel biomarkers have been developed that can lead to novel therapeutic avenues aiming to ameliorate the patients’ symptoms and lives. This review summarizes the advances in therapeutic approaches for CDG.

Overexpression of zinc-α2-glycoprotein suppressed seizures and seizure-related neuroflammation in pentylenetetrazol-kindled rats

BACKGROUND

Zinc-α2-glycoprotein (ZAG) is a 42-kDa protein reported as an anti-inflammatory adipocytokine. Evidences from clinical and experimental studies revealed that brain inflammation plays important roles in epileptogenesis and seizure. Interestingly, closely relationship between ZAG and many important inflammatory mediators has been proven. Our previous study identified ZAG in neurons and found that ZAG is decreased in epilepsy and interacts with TGFβ and ERK. This study aimed to investigate the role of ZAG in seizure and explore its effect on seizure-related neuroinflammation.

METHODS

We overexpressed AZGP1 in the hippocampus of rats via adeno-associated virus vector injection and observed their seizure behavior and EEG after pentylenetetrazol (PTZ) kindling. The level of typical inflammation mediators including TNFα, IL-6, TGFβ, ERK, and ERK phosphorylation were determined.

RESULTS

The overexpression of AZGP1 reduced the seizure severity, prolonged the latency of kindling, and alleviated epileptiform discharges in EEG changes induced by PTZ. Overexpression of AZGP1 also suppressed the expression of TNFα, IL-6, TGFβ, and ERK phosphorylaton in PTZ-kindled rats.

CONCLUSIONS

ZAG may inhibit TGFβ-mediated ERK phosphorylation and inhibit neuroinflammation mediated by TNFα and IL-6, suggesting ZAG may suppress seizure via inhibiting neuroinflammation. ZAG may be a potential and novel therapeutic target for epilepsy.

Clinical studies and anti-inflammatory mechanisms of treatments

In this exciting era, we are coming closer and closer to bringing an anti-inflammatory therapy to the clinic for the purpose of seizure prevention, modification, and/or suppression. At present, it is unclear what this approach might entail, and what form it will take. Irrespective of the therapy that ultimately reaches the clinic, there will be some commonalities with regard to clinical trials. A number of animal models have now been used to identify inflammation as a major underlying mechanism of both chronic seizures and the epileptogenic process. These models have demonstrated that specific anti-inflammatory treatments can be effective at both suppressing chronic seizures and interfering with the process of epileptogenesis. Some of these have already been evaluated in early phase clinical trials. It can be expected that there will soon be more clinical trials of both "conventional, broad spectrum" anti-inflammatory agents and novel new approaches to utilizing specific anti-inflammatory therapies with drugs or other therapeutic interventions. A summary of some of those approaches appears below, as well as a discussion of the issues facing clinical trials in this new domain.

Lipids as central modulators of sensory TRP channels

The transient receptor potential (TRP) ion channel family is involved in a diversity of physiological processes including sensory and homeostatic functions, as well as muscle contraction and vasomotor control. Their dysfunction contributes to the etiology of several diseases, being validated as therapeutic targets. These ion channels may be activated by physical or chemical stimuli and their function is highly influenced by signaling molecules activated by extracellular signals. Notably, as integral membrane proteins, lipid molecules also modulate their membrane location and function either by direct interaction with the channel structure or by modulating the physico-chemical properties of the cellular membrane. This lipid-based modulatory effect is being considered an alternative and promising approach to regulate TRP channel dysfunction in diseases. Here, we review the current progress in this exciting field highlighting a complex channel regulation by a large diversity of lipid molecules and suggesting some diseases that may benefit from a membrane lipid therapy. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.

GC-MS-Based metabolomics discovers a shared serum metabolic characteristic among three types of epileptic seizures

OBJECTIVE

Understanding the overall and common metabolic changes of seizures can provide novel clues for their control and prevention. Here, we aim to investigate the global metabolic feature of serum for three types of seizures.

METHODS

We recruited 27 patients who had experienced a seizure within 48h (including 11 who had a generalized seizure, nine who had a generalized seizure secondary to partial seizure and seven who had a partial seizure) and 23 healthy controls. We analyzed the global metabolic changes of serum after seizures using gas chromatography-mass spectrometry-based metabolomics. Based on differential metabolites, the metabolic pathways and their potential to diagnose seizures were analyzed, and metabolic differences among three types of seizures were compared.

RESULTS

The metabolic profiles of serum were distinctive between the seizure group and the controls but were not different among the three types of seizures. Compared to the controls, patients with seizures had higher levels of lactate, butanoic acid, proline and glutamate and lower levels of palmitic acid, linoleic acid, elaidic acid, trans-13-octadecenoic acid, stearic acid, citrate, cysteine, glutamine, asparagine, and glyceraldehyde in the serum. Furthermore, these differential metabolites had common change trends among the three types of seizures. Related pathophysiological processes reflected by these metabolites are energy deficit, inflammation, nervous excitation and neurotoxicity. Importantly, transamination inhibition is suspected to occur in seizures. Lactate, glyceraldehyde and trans-13-octadecenoic acid in serum jointly enabled a precision of 92.9% for diagnosing seizures.

CONCLUSIONS

There is a common metabolic feature in three types of seizures. Lactate, glyceraldehyde and trans-13-octadecenoic acid levels jointly enable high-precision seizure diagnosis.

Anticonvulsant effect of argan oil on pilocarpine model induced status epilepticus in wistar rats

Argan oil (AO) is rich in oleic and linoleic acids, polyphenols, sterols, and tocopherols. This composition gives it numerous beneficial pharmacological effects such as hypolipemiant, hypotensive, and antiproliferative. Oxidative stress is a mechanism of cell death induced by seizures and status epilepticus (SE). This study aims at investigating AO effects on (i) latency to first seizure, seizure severity, weight loss, mortality rate, (ii) lipid peroxidation level, nitrite level, and catalase activity in the hippocampus after SE induced by pilocarpine (PC). Wistar rats (1-month old) were daily administered by oral gavage with AO (1 ml/100 g/day) or with NaCl 0.9% during 2 months before receiving PC (400 mg/kg). After the PC injection, all groups were observed for 24 h. The catalase activity, the lipid peroxidation, and nitrite concentrations were measured using spectrophotometric methods. AO pretreatment increased the latency to first seizures, decreased the weight loss, and reduced mortality rate after SE. AO pretreatment produces significant decrease of the lipid peroxidation and nitrite levels. On the contrary, AO increased the catalase activity in rat hippocampus after seizures. For the first time, our results suggest that AO pretreatment is capable of attenuating seizure severity and oxidative stress in the hippocampus of Wistar rats. This indicates that AO may exhibit a neuroprotection against the temporal lobe epilepsy. Further investigations are in progress to confirm this pharmacological property.

In silico Screening and Evaluation of the Anticonvulsant Activity of Docosahexaenoic Acid-Like Molecules in Experimental Models of Seizures

Background:

Resistance to antiepileptic drugs and the intolerability in 20-30% of the patients raises demand for developing new drugs with improved efficacy and safety. Acceptable anticonvulsant activity, good tolerability, and inexpensiveness of docosahexaenoic acid (DHA) make it as a good candidate for designing and development of the new anticonvulsant medications.

Methods:

Ten DHA-based molecules were screened based on in silico screening of DHA-like molecules by root-mean-square deviation of atomic positions, the biological activity score of Professional Association for SQL Server, and structural requirements suggested by pharmacophore design. Anticonvulsant activity was tested against clonic seizures induced by pentylenetetrazole (PTZ, 60 mg/kg, i.p.) and tonic seizures induced by maximal electroshock (MES, 50 mA, 50 Hz, 1 ms duration) by intracerebroventricular (i.c.v.) injection of the screened compounds to mice.

Results:

Among screened compounds, 4-Phenylbutyric acid, 4-Biphenylacetic acid, phenylacetic acid, and 2-Phenylbutyric acid showed significant protective activity in pentylenetetrazole test with ED₅₀ values of 4, 5, 78, and 70 mM, respectively. In MES test, shikimic acid and 4-tert-Butylcyclo-hexanecarboxylic acid showed significant activity with ED₅₀ values 29 and 637 mM, respectively. Effective compounds had no mortality in mice up to the maximum i.c.v. injectable dose of 1 mM.

Conclusion:

Common electrochemical features and three-dimensional spatial structures of the effective compounds suggest the involvement of the anticonvulsant mechanisms similar to the parent compound DHA.

Polyunsaturated fatty acid supplementation for drug-resistant epilepsy

BACKGROUND

An estimated 1% to 3% of all individuals will receive a diagnosis of epilepsy during their lives, which corresponds to approximately 50 million affected people worldwide. The real prevalence is possibly higher because epilepsy is underreported in developing countries. Although most will achieve adequate control of their disease though the use of medication, approximately 25% to 30% of all those with epilepsy are refractory to pharmacological treatment and will continue to have seizures despite the use of two or more agents in adequate dosages. Over the last decade, researchers have tested the use of polyunsaturated fatty acid (PUFA) supplements for the treatment of refractory epilepsy, with inconsistent results. There have also been some concerns about the use of omega-3 PUFA compounds because they reduce platelet aggregation and could, in theory, cause bleeding.

OBJECTIVES

To assess the effectiveness and tolerability of omega-3 polyunsaturated fatty acids (eicosapentaenoic acid-EPA and docosahexanoic acid-DHA) in the control of seizures in people with refractory epilepsy.

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialised Register (from inception up to November 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, issue 11), MEDLINE (1948 to November 2015), EMBASE (1980 to November 2015), SCOPUS (1823 to November 2015); LILACS (Literatura Latino-Americana e do Caribe de Informação em Ciências da Saúde) (1982 to November 2015); ClinicalTrials.gov; World Health Organization (WHO) International Clinical Trials Registry Platform (November 2015). No language restrictions were imposed. We contacted study authors for additional and unpublished information and screened the reference lists of retrieved citations for potentially eligible studies not identified through the electronic search.

SELECTION CRITERIA

All randomised and quasi-randomised studies using PUFAs for the treatment of drug-resistant epilepsy.

DATA COLLECTION AND ANALYSIS

Two review authors were involved in study selection, data extraction and quality assessment of the included trials. The following outcomes were assessed: seizure freedom, seizure reduction, improvement in quality of life, potential adverse effects, gastrointestinal effects, drop-out rates and changes in plasma lipid profile. Primary analyses were by intention to treat.

MAIN RESULTS

Eight studies were identified as potentially relevant; three fulfilled the selection criteria and were included in the review. Two placebo-controlled, double blind trials involving adult participants were conducted in developed countries, while one placebo-controlled, single blind trial involving children was conducted in a developing country (Egypt). Bromfield 2008 randomised 27 American adults to receive 2.2 g/day of omega-3 PUFAs (EPA:DHA in a 3:2 ratio) or placebo. Yuen 2005 randomised 58 people in the UK to approximately 1.7 g/day omega-3 PUFAs (1g EPA and 0.7g DHA) or placebo. Reda 2015 randomised 70 Egyptian children to receive 3 ml/day of 1200 mg fish oil (providing 0.24 g DHA and 0.36 g EPA) or placebo. The three studies recruited a total of 155 subjects (85 adults and 70 children); 78 of them (43 adults and 35 children) were randomised to PUFAs and 77 (42 adults and 35 children) to placebo. All participants were followed for up to 12 weeks. Seizure freedom was reported by only one study, with a high risk of bias, involving exclusively children. The risk estimate for this outcome was significantly higher in the children receiving PUFA compared to the control group (risk ratio (RR) 20.00, 95% confidence interval (CI) 2.84 to 140.99, 1 study, 70 children). Similarly, PUFA supplementation was associated with a significant difference in the proportion of children with at least 50% reduction in seizure frequency (RR 33.00 95% CI 4.77 to 228.15, 1 study with a high risk of bias, 70 children). However, this effect was not observed when the data from two studies including adult participants were pooled (RR 0.57, 95% CI 0.19 to 1.75, I² 0%, 2 studies, 78 participants, low-quality evidence). One of our three primary outcomes (adverse effects related to bleeding) was not assessed in any of the studies included in this review. There were no significant differences between the PUFA and control groups in relation to gastrointestinal effects (RR 0.78, 95% CI 0.32 to 1.89, 2 studies, 85 participants, low-quality evidence).Supplementation with PUFA did not produce significant differences in mean frequency of seizures, quality of life or other side effects.

AUTHORS' CONCLUSIONS

In view of the limited number of studies and small sample sizes, there is not enough evidence to support the use of PUFA supplementation in people with refractory epilepsy. More trials are needed to assess the benefits of PUFA supplementation in the treatment of drug-resistant epilepsy.

Ketogenic Diet, but Not Polyunsaturated Fatty Acid Diet, Reduces Spontaneous Seizures in Juvenile Rats with Kainic Acid-induced Epilepsy

Background and Purpose:

The high-fat, low-carbohydrate ketogenic diet (KD) is effective in many cases of drug-resistant epilepsy, particularly in children. In the classic KD, fats consist primarily of long-chain saturated triglycerides. Polyunsaturated fatty acids (PUFAs), especially the n-3 type, decrease neuronal excitability and provide neuroprotection; pilot human studies have raised the possibility of using PUFAs to control seizures in patients.

Methods:

To determine the relative roles of the KD and PUFAs in an animal model, we induced epilepsy in juvenile rats (P29–35) using intraperitoneal kainic acid (KA). KA caused status epilepticus in all rats. Two days after KA, rats were randomized to one of 4 dietary groups: Control diet; PUFA diet; KD; or KD plus PUFA. All diets were administered isocalorically at 90% of the rat recommended daily calorie requirement. Spontaneous recurrent seizures (SRS) were assessed for 3 months after diet randomization.

Results:

Rats receiving the KD or KD-PUFA diet had significantly fewer SRS than those receiving the Control diet or PUFA diet. The PUFA diet did not reduce SRS compared to the Control diet.

Conclusions:

In the KA epilepsy model, the KD protects against SRS occurrence but dietary enhancement with PUFA does not afford additional protection against spontaneous seizures.

Antiepileptic drugs in development pipeline: A recent update

Epilepsy is the most common neurological disorder which significantly affects the quality of life and poses a health as well as economic burden on society. Epilepsy affects approximately 70 million people in the world. The present article reviews the scientific rationale, brief pathophysiology of epilepsy and newer antiepileptic drugs which are presently under clinical development. We have searched the investigational drugs using the key words ‘antiepileptic drugs,’ ‘epilepsy,’ ‘Phase I,’ ‘Phase II’ and ‘Phase III’ in American clinical trial registers (clinicaltrials.gov), the relevant published articles using National Library of Medicine's PubMed database, company websites and supplemented results with a manual search of cross-references and conference abstracts. This review provides a brief description about the antiepileptic drugs which are targeting different mechanisms and the clinical development status of these drugs. Besides the presence of old as well as new AEDs, still there is a need of new drugs or the modified version of old drugs in order to make affected people free of seizures. An optimistic approach should be used to translate the success of preclinical testing to clinical practice. There is an urgent need to improve animal models and to explore new targets with better understanding in order to develop the novel drugs with more efficacy and safety.

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This review primarily focused on antiepileptic drugs under clinical development.

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The more realistic approach is needed to discover and develop the novel antiepileptic drugs.

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Modification of conventional drugs or search of newer targets can lead to development of promising antiepileptic drugs.

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To develop more efficacious and safe drugs for treatment of epilepsy and refractory seizures

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There are a number of novel antiepileptic compounds which are under various stages of drug development.

Mechanisms of Action of Antiseizure Drugs and the Ketogenic Diet

Antiseizure drugs (ASDs), also termed antiepileptic drugs, are the main form of symptomatic treatment for people with epilepsy, but not all patients become free of seizures. The ketogenic diet is one treatment option for drug-resistant patients. Both types of therapy exert their clinical effects through interactions with one or more of a diverse set of molecular targets in the brain. ASDs act by modulation of voltage-gated ion channels, including sodium, calcium, and potassium channels; by enhancement of γ-aminobutyric acid (GABA)-mediated inhibition through effects on GABAA receptors, the GABA transporter 1 (GAT1) GABA uptake transporter, or GABA transaminase; through interactions with elements of the synaptic release machinery, including synaptic vesicle 2A (SV2A) and α2δ; or by blockade of ionotropic glutamate receptors, including α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) receptors. The ketogenic diet leads to increases in circulating ketones, which may contribute to the efficacy in treating pharmacoresistant seizures. Production in the brain of inhibitory mediators, such as adenosine, or ion channel modulators, such as polyunsaturated fatty acids, may also play a role. Metabolic effects, including diversion from glycolysis, are a further postulated mechanism. For some ASDs and the ketogenic diet, effects on multiple targets may contribute to activity. Better understanding of the ketogenic diet will inform the development of improved drug therapies to treat refractory seizures.

Plasma non-esterified docosahexaenoic acid is the major pool supplying the brain

Despite being critical for normal brain function, the pools that supply docosahexaenoic acid (DHA) to the brain are not agreed upon. Using multiple kinetic models in free-living adult rats, we first demonstrate that DHA uptake from the plasma non-esterified fatty acid (NEFA) pool predicts brain uptake of DHA upon oral administration, which enters the plasma NEFA pool as well as multiple plasma esterified pools. The rate of DHA loss by the brain is similar to the uptake from the plasma NEFA pool. Furthermore, upon acute iv administration, although more radiolabeled lysophosphatidylcholine (LPC)-DHA enters the brain than NEFA-DHA, this is due to the longer plasma half-life and exposure to the brain. Direct comparison of the uptake rate of LPC-DHA and NEFA-DHA demonstrates that uptake of NEFA-DHA into the brain is 10-fold greater than LPC-DHA. In conclusion, plasma NEFA-DHA is the major plasma pool supplying the brain.

Fish Oil Intake and Seizure Control in Children with Medically Resistant Epilepsy

Background:

There is considerable evidence which suggests that Omega 3 polyunsaturated fatty acids may have a potential use in the treatment of epilepsy.

Aim:

The study was to investigate the effect of Omega 3 polyunsaturated fatty acids (as fish oil supplementation) in reducing the frequency and severity of epileptic seizures in children with medically resistant epilepsy.

Materials and Methods:

In the case-control study, a total of 70 children with medically resistant epilepsy underwent assessment of the frequency and severity of the epileptic attacks at baseline, after one month, two months and three months from the beginning of the study; 35 children received fish oil and the other 35 children received placebo.

Results:

The number of children who received fish oil, having 0 epileptic attacks increased from 0%, before starting the study, up to 57.1% at the end of the third month, while the improvement was minimal in the placebo group, with a significant difference in the improvement between the intervention and the control groups. There was no statistically significant difference in improvement in the severity of the seizures either between cases and control or between the beginning and the end of the study.

Conclusion:

Omega 3 polyunsaturated fatty acids elevated the seizure threshold in epileptic patients and may help in achieving seizure control.