Classic Ketogenic Diet and Modified Atkins Diet in SLC2A1 Positive and Negative Patients with Suspected GLUT1 Deficiency Syndrome: A Single Center Analysis of 18 Cases

The use of ketogenic diets in children living with drug-resistant epilepsy, glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency: A scoping review

BACKGROUND

The ketogenic diet (KD) is a high fat, moderate protein and very low carbohydrate diet. It can be used as a medical treatment for drug-resistant epilepsy (DRE), glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency. The aim of this scoping review was to map the KD literature, with a focus on epilepsy and associated metabolic conditions, to summarise the current evidence-base and identify any gaps.

METHODS

This review was conducted using JBI scoping review methodological guidance and the PRISMA extension for scoping reviews reporting guidance. A comprehensive literature search was conducted in September 2021 and updated in February 2024 using MEDLINE, CINAHL, AMED, EmBASE, CAB Abstracts, Scopus and Food Science Source databases.

RESULTS

The initial search yielded 2721 studies and ultimately, data were extracted from 320 studies that fulfilled inclusion criteria for the review. There were five qualitative studies, and the remainder were quantitative, including 23 randomised controlled trials (RCTs) and seven quasi-experimental studies. The USA published the highest number of KD studies followed by China, South Korea and the UK. Most studies focused on the classical KD and DRE. The studies key findings suggest that the KD is efficacious, safe and tolerable.

CONCLUSIONS

There are opportunities available to expand the scope of future KD research, particularly to conduct high-quality RCTs and further qualitative research focused on the child's needs and family support to improve the effectiveness of KDs.

Analysis of dietary fats intake and lipid profile in Chilean patients with glucose transport type 1 deficiency syndrome: similarities and differences with the reviewed literature

Introduction

Glucose transporter type 1 deficiency syndrome (GLUT1-DS) is a neurological disorder caused by mutations in the SLC2A1 gene. The main treatment is ketogenic diet therapy (KDT), which changes the brain's energy substrate from glucose to ketone bodies. The diet controls seizures, but there may be side effects such as dyslipidemia. This study aimed to describe the type of fats ingested by the Chilean cohort of patients with GLUT1-DS and analyze for alterations in the lipid profile.

Methods

A GLUT1-DS group and a control group were formed, each with 13 subjects who were matched by age, gender, and nutritional status. Anthropometry, dietary intake, including types of fat, and blood tests were evaluated (lipid and liver profile, and 25-hydroxyvitamin D levels).

Results

A high-fat diet, especially saturated fat, was identified in the GLUT1-DS group (38% of total calories), with the use of medium-chain triglycerides (17% of total calories). In addition, GLUT1-DS participants had a higher intake of monounsaturated (MUFA) and polyunsaturated (PUFA) fats and adequate consumption of omega-3 (2% of total calories). Despite the GLUT1-DS group receiving on average 80% of its total energy as fats, it is important to highlight that 50% are MUFA+PUFA fats, there were no significant differences in the lipid and liver profile compared to the control group.

Conclusion

KDT did not negatively impact lipid profile, despite a high intake of fats. It is important to monitor lipid profiles, in a personalized and constant manner, to prevent future nutritional risks.

Ketogenic diet therapy in children with epilepsy caused by SLC2A1 mutations: a single-center single-arm retrospective study

BACKGROUND

This retrospective study assessed the efficacy and safety of ketogenic diet therapies in children with epilepsy caused by SLC2A1 genetic mutations and glucose transporter type 1 deficiency syndrome.

METHODS

Pediatric patients with epilepsy symptoms admitted to our medical center between January 2017 and October 2021 were included if they presented with an SLC2A1 genetic mutation on whole-exome sequencing. We analyzed the patients' convulsions and treatment with antiepileptic drugs. The patients were followed up at different time periods after ketogenic diet therapies.

RESULTS

Six patients with SLC2A1 mutations were included in this study. The patients had seizures of different types and frequencies, and they took antiepileptic drugs to relieve their symptoms. They were then treated with a ketogenic diet for at least four months. We analyzed epilepsy control rates at 1, 2, 3, 6, and 12 months after ketogenic diet treatment. All patients were seizure-free within a month of receiving the diet therapy. All patients were followed up for six months, three were followed up for 12 months after the treatment, and there was no recurrence of epilepsy during this period. After antiepileptic drug withdrawal, none of the patients experienced seizure relapse when receiving ketogenic diet treatment alone. No severe adverse events occurred during the therapy.

CONCLUSIONS

Ketogenic diet therapy is very effective and safe for the treatment of epilepsy caused by SLC2A1 mutations. Therefore, patients with glucose transporter type 1 deficiency syndrome caused by SLC2A1 mutations should begin ketogenic diet treatment as soon as possible.

[Fourteenth Jesús Culebras Lecture. Ketogenic diet, a half-discovered treatment]

Introduction

The ketogenic diet was an amazing approach to treating epilepsy from its beginning. The body undergoes a change in obtaining energy, going from depending on carbohydrates to depending on fats, and then a whole series of biochemical routes are launched that, independently but also complementary, give rise to a set of effects that benefit the patient. This search for its mechanism of action, of devising how to improve compliance and take advantage of it for other diseases has marked its trajectory. This article briefly reviews these aspects, emphasizing the importance of continuing to carry out basic and clinical research so that this treatment can be applied with solid scientific bases.

Effect of the ketogenic diet as a treatment for refractory epilepsy in children and adolescents: a systematic review of reviews

CONTEXT

Epilepsy is one of the most prevalent neurological disorders in childhood. Antiepileptic drugs are the preferred treatment. However, 30% of children continue suffering seizures. A ketogenic diet (KD) is one of the emerging alternative treatments.

OBJECTIVE

This review aims to analyze the current evidence regarding the use of a KD for the treatment of refractory epilepsy (RE) in childhood.

DATA SOURCES

A systematic review of reviews was performed, based on MEDLINE (PubMed) as at January 2021.

DATA EXTRACTION

The data extracted included the first author's last name; the year of publication; the country; the study design; the population; the diagnosis, concept, and description of KD types; and major outcome.

RESULTS

Twenty-one reviews were included, 8 with systematic methodology (2 of them included a meta-analysis) and 13 with unsystematic methodology. The main difference between the 2 types of reviews is the reproducibility of their methodology. Therefore, the results of each type of review were analyzed separately. Each type of review described 4 categories of KD: classic KD, modified Atkins diet (MAD), use of medium-chain triglycerides (MCTs), and low glycemic index treatment (LGIT). In terms of effectiveness, the considered systematic reviews reported reductions in the frequency of seizures greater than 50% in about half of the patients. Reviews without systematic methodology reported that 30%-60% of the children showed a 50% or greater reduction in seizures. The most frequently described adverse effects in the 8 systematic reviews were: vomiting (6/8), constipation (6/8), and diarrhea (6/8); and in the unsystematic reviews: vomiting and nausea (10/13), constipation (10/13), and acidosis (9/13).

CONCLUSION

KD can be an effective treatment for RE, with a more than 50% reduction in the frequency of seizures and cognitive improvement being achieved in half of the pediatric patients. The effectiveness of the various types of KD is comparable, and the KD can be adapted to the needs of the patient.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021244142.

One Molecule for Mental Nourishment and More: Glucose Transporter Type 1—Biology and Deficiency Syndrome

Glucose transporter type 1 (Glut1) is the main transporter involved in the cellular uptake of glucose into many tissues, and is highly expressed in the brain and in erythrocytes. Glut1 deficiency syndrome is caused mainly by mutations of the SLC2A1 gene, impairing passive glucose transport across the blood–brain barrier. All age groups, from infants to adults, may be affected, with age-specific symptoms. In its classic form, the syndrome presents as an early-onset drug-resistant metabolic epileptic encephalopathy with a complex movement disorder and developmental delay. In later-onset forms, complex motor disorder predominates, with dystonia, ataxia, chorea or spasticity, often triggered by fasting. Diagnosis is confirmed by hypoglycorrhachia (below 45 mg/dL) with normal blood glucose, 18F-fluorodeoxyglucose positron emission tomography, and genetic analysis showing pathogenic SLC2A1 variants. There are also ongoing positive studies on erythrocytes’ Glut1 surface expression using flow cytometry. The standard treatment still consists of ketogenic therapies supplying ketones as alternative brain fuel. Anaplerotic substances may provide alternative energy sources. Understanding the complex interactions of Glut1 with other tissues, its signaling function for brain angiogenesis and gliosis, and the complex regulation of glucose transportation, including compensatory mechanisms in different tissues, will hopefully advance therapy. Ongoing research for future interventions is focusing on small molecules to restore Glut1, metabolic stimulation, and SLC2A1 transfer strategies. Newborn screening, early identification and treatment could minimize the neurodevelopmental disease consequences. Furthermore, understanding Glut1 relative deficiency or inhibition in inflammation, neurodegenerative disorders, and viral infections including COVID-19 and other settings could provide clues for future therapeutic approaches.

Analysis of Factors That May Affect the Effectiveness of Ketogenic Diet Treatment in Pediatric and Adolescent Patients

Purpose. The aim was to find predictors for ketogenic diet (KD) treatment effectiveness. In addition, recognized factors influencing the efficacy of KD were analyzed based on the ILAE (International League Against Epilepsy) proposed Classification and Definition of the Epilepsy Syndromes. Methods. A sample of 42 patients treated with KD were analyzed. The effectiveness of KD was assessed according to the type of diet, the type of seizures, and the known (KE) or undetermined genetic etiology (UNKE). The group of KE consisted of patients with CACNA1S, CHD2, DEPDC5, KIF1A, PIGN, SCN1A, SCN8A, SLC2A1, SYNGAP1 pathogenic variants. The usefulness of the new Classification and Definition of Epilepsy Syndromes proposed by the ILAE was evaluated. Results. KD therapy was effective in 69.05% of cases. No significant correlation was observed with the type of diet used. KE was related to greater effectiveness after KD treatment. KD treatment was most effective in the reduction of non-focal seizures. Considering the ILAE proposed classification, it was found that KD efficacy was higher in patients with simultaneous focal and tonic-clonic seizures compared to patients with only tonic-clonic or focal seizures. Conclusion. The occurrence of focal seizures does not determine the potential ineffectiveness of treatment with a ketogenic diet. A significant efficacy of ketogenic diet treatment was observed in the group of patients with focal and generalized seizures, as well as epileptic and developmental encephalopathies. The etiology of epileptic seizures plays a more significant role. The new classification will make it easier to select patients who can benefit from this form of treatment.