Do Glut1 (glucose transporter type 1) defects exist in epilepsy patients responding to a ketogenic diet?

Ketogenic diet for infants with epilepsy: A literature review

The ketogenic diet (KD) is an established, nonpharmacological treatment for drug-resistant epilepsy (DRE). Actually, KD and its variants have been shown to be elective and resolute for patients with glucose transporter type 1 (GLUT1) deficiency. The aim of this review was to study the use of KD and its variants in infancy, including the neonatal age, and demonstrate the safety and efficacy of this treatment in patients with the age of 0-23 months affected by DRE already subjected to pharmacological approach attempts. A literature search was conducted using PubMed as the medical database source. We used the age limit of 0-23 months, and we considered only articles published between the years 2015 and 2018, in light of increasing interest worldwide in the use of KD and its variants to manage DRE. We included 52 publications: 1 Cochrane study, 22 retrospective studies, 9 prospective studies, 4 randomized controlled trials (RCTs), 12 clinical cases, and 4 clinical reviews. Literature data showed that KD and its variants are safe and useful in patients with the age of 0-23 months with DRE. Classical KD is of first choice in the treatment of GLUT1 deficiency. Earlier introduction of KD in GLUT1 promises a better outcome and a decrease in seizure frequency in these patients.

The Anticonvulsant Effects of Ketogenic Diet on Epileptic Seizures and Potential Mechanisms

Background:

Epilepsy is a syndrome of brain dysfunction induced by the aberrant excitability of certain neurons. Despite advances in surgical technique and anti-epileptic drug in recent years, recurrent epileptic seizures remain intractable and lead to a serious morbidity in the world. The ketogenic diet refers to a high-fat, low-carbohydrate and adequate-protein diet.Currently, its beneficial effects on epileptic seizure reduction have been well established. However, the detailed mechanisms underlying the anti-epileptic effects of ketogenic diet are still poorly understood. In this article, the possible roles of ketogenic diet on epilepsy were discussed.

Methods:

Data was obtained from the websites including Web of Science, Medline, Pubmed,Scopus, based on these keywords: “Ketogenic diet” and “epilepsy”.

Results:

As shown in both clinical and basic studies, the therapeutic effects of ketogenic diet might involve neuronal metabolism, neurotransmitter function, neuronal membrane potential and neuron protection against ROS.

Conclusion:

In this review, we systematically reviewed the effects and possible mechanisms of ketogenic diet on epilepsy, which may optimize the therapeutic strategies against epilepsy.

Individualizing Treatment Approaches for Epileptic Patients with Glucose Transporter Type1 (GLUT-1) Deficiency

Monogenic and polygenic mutations are important contributors in patients suffering from epilepsy, including metabolic epilepsies which are inborn errors of metabolism with a good respond to specific dietetic treatments. Heterozygous variation in solute carrier family 2, facilitated glucose transporter member 1 (SLC2A1) and mutations of the GLUT1/SLC2A2 gene results in the failure of glucose transport, which is related with a glucose type-1 transporter (GLUT1) deficiency syndrome (GLUT1DS). GLUT1 deficiency syndrome is a treatable disorder of glucose transport into the brain caused by a variety of mutations in the SLC2A1 gene which are the cause of different neurological disorders also with different types of epilepsy and related clinical phenotypes. Since patients continue to experience seizures due to a pharmacoresistance, an early clinical diagnosis associated with specific genetic testing in SLC2A1 pathogenic variants in clinical phenotypes could predict pure drug response and might improve safety and efficacy of treatment with the initiation of an alternative energy source including ketogenic or analog diets in such patients providing individualized strategy approaches.

Prevalence of Genetic Disorders and GLUT1 Deficiency in a Ketogenic Diet Clinic

Between July of 2012 and December of 2014, 39 patients were enrolled prospectively to investigate the prevalence of glucose transporter 1 (GLUT1) deficiency in a ketogenic diet clinic. None of them had GLUT1 deficiency. All patients seen in the same clinic within the same period were reviewed retrospectively. A total of 18 of these 85 patients had a genetic diagnosis, including GLUT1 deficiency, pathogenic copy number variants, congenital disorder of glycosylation, neuronal ceroid lipofuscinosis type II, mitochondrial disorders, tuberous sclerosis, lissencephaly, and SCN1A-, SCN8A-, and STXBP1-associated epileptic encephalopathies. The prevalence of genetic diagnoses was 21% and prevalence of GLUT1 deficiency was 2.4% in our retrospective cohort study.