Limited efficacy of the ketogenic diet in the treatment of highly refractory epileptic spasms

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.

Core outcome set development for childhood epilepsy treated with ketogenic diet therapy: Results of a scoping review and parent interviews

PURPOSE

Clinical trials on childhood epilepsy treated with ketogenic diet (KD) use a wide range of outcomes, however, patients and decision-makers often do not perceive the outcomes used as the most important. We sought parental opinion on outcomes of importance and compared these to outcomes reported in published research.

METHODS

Ethical approval (London-Surrey-REC19/LO/1680). A scoping review identified outcomes reported in previous studies of childhood epilepsy and KD. Parents were recruited from nine KD centres (UK), charities and social media (international), then interviewed (Jan-April 2020) to explore priority outcomes. Content analysis identified all outcomes in transcripts. Parent identified outcomes were compared with those in the scoping review. Outcomes were collated and grouped into domains according to the COMET Taxonomy.

RESULTS

Of 2663 articles;147 met inclusion criteria. 921 verbatim outcomes were sorted into 90 discrete outcomes, reduced to 70 in consultation with the study advisory group, then classified into 21 domains. Parents (n = 21) identified 39 outcomes as important from the scoping review and seven new outcomes. They prioritised both physiological and functional outcomes in contrast to past studies, which prioritised physiological outcomes.

CONCLUSION

Little consistency exists in the outcomes used in childhood epilepsy and KD research. Those traditionally used do not adequately reflect parents' important outcomes for their child. Clinical trials should consider the broader priorities of parents when choosing outcomes, in particular, functional outcomes. Identified outcomes will inform an international two-round Delphi-study with parent, professional and researcher participants to develop a core outcome set for this clinical area (COMET registration #1116).

Potential induction of epileptic spasms by nonselective voltage-gated sodium channel blockade: Interaction with etiology

PURPOSE

Epileptic spasms are often preceded by focal (or multifocal) seizures. Based on a series of case reports suggesting that carbamazepine and oxcarbazepine may induce epileptic spasms, we set out to rigorously evaluate the potential association between exposure to voltage-gated sodium channel blockade and latency to epileptic spasms.

METHODS

We identified 50 cases (children with focal seizures and evolution to epileptic spasms) and 50 controls (children with focal seizures without evolution to epileptic spasms). For each patient, we reviewed all sequential neurology encounters between onset of epilepsy and emergence of epileptic spasms. For each encounter we recorded seizure-frequency and all anti-seizure therapy exposures. Using multivariable Cox proportional hazards regression, we evaluated the association between voltage-gated sodium channel exposure (carbamazepine, oxcarbazepine, lacosamide, or phenytoin) and latency to epileptic spasms onset, with adjustment for etiology and seizure-frequency.

RESULTS

Latency to epileptic spasms onset was independently associated with exposure to sodium channel blockade (hazard ratio = 2.4; 95% CI 1.1-5.2; P = 0.03) and high-risk etiology (hazard ratio = 2.8; 95% CI 1.5-5.1; P = 0.001). With assessment for interaction between sodium channel blockade and etiology, we identified an estimated 7-fold increased risk of epileptic spasms with the combination of sodium channel blockade and high-risk etiology (hazard ratio = 7.0, 95% CI 2.5-19.8; P < 0.001).

CONCLUSION

This study suggests that voltage-gated sodium channel blockade may induce epileptic spasms among children at risk on the basis of etiology. Further study is warranted to replicate these findings, ascertain possible drug- and dose-specific risks, and identify potential mechanisms of harm.

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.

Ketogenic diet experience at Ondokuz Mayıs University

BACKGROUND AND OBJECTIVES

The ketogenic diet (KD) is a special diet that is rich in fat, and poor in protein and carbohydrates. KD is the first-line treatment for some metabolic disorders, and is also used in resistant epilepsy, autism, cancer, Parkinson, Alzheimer's diseases, and stroke. The KD team consists of a doctor (child neurologist), nurse, and dietician. After diet adjustment, family training, metabolic tests, consultations, material supply, the initial and follow-up stages are performed by this team.

METHOD

Retrospective data analyses of patients followed at ketogenic diet outpatient clinic were made.

RESULTS

Fourteen patients (6F, 8M) continued their KD treatment, and nine (4F, 5M) of them stopped the treatment. KD treatment duration for those who continued KD was between 1 and 24 months (mean 7.1, median 4), and KD duration of those who left was between 0.5 and 12 months (mean 5, median 5). Three patients became seizure-free, seven patients had ≥ 50% reduction in their seizures, and four patients had no change in seizure. Anti-epileptic drugs could be reduced in five patients. Improvement in perception and social behaviour of the children was expressed by the families. Although one of the patients was seizure-free and the others had 75% decrease in seizures, they left KD due to frequent infection and family desire. The other seven patients who left KD had no changes in their seizures, but four of them continued KD in less than 2 months, and two of them only for 15 days. Weight loss, family problems, infection, and financial concerns were the reasons for them leaving.

CONCLUSION

Today, although the approach is changing, KD still comes to mind for the most resistant, troubled patients. Stopping the patients' seizures, opening their perceptions, and reducing the medications are satisfactory results. We wanted to share our small group of patients and their results in the hope of expanding the ketogenic diet.

Diet in the Treatment of Epilepsy: What We Know So Far

Epilepsy is a chronic and debilitating neurological disorder, with a worldwide prevalence of 0.5-1% and a lifetime incidence of 1-3%. An estimated 30% of epileptic patients continue to experience seizures throughout life, despite adequate drug therapy or surgery, with a major impact on society and global health. In recent decades, dietary regimens have been used effectively in the treatment of drug-resistant epilepsy, following the path of a non-pharmacological approach. The ketogenic diet and its variants (e.g., the modified Atkins diet) have an established role in contrasting epileptogenesis through the production of a series of cascading events induced by physiological ketosis. Other dietary regimens, such as caloric restriction and a gluten free diet, can also exert beneficial effects on neuroprotection and, therefore, on refractory epilepsy. The purpose of this review was to analyze the evidence from the literature about the possible efficacy of different dietary regimens on epilepsy, focusing on the underlying pathophysiological mechanisms, safety, and tolerability both in pediatric and adult population. We believe that a better knowledge of the cellular and molecular biochemical processes behind the anticonvulsant effects of alimentary therapies may lead to the development of personalized dietary intervention protocols.

Modeling epileptic spasms during infancy: Are we heading for the treatment yet?

Infantile spasms (IS or epileptic spasms during infancy) were first described by Dr. William James West (aka West syndrome) in his own son in 1841. While rare by definition (occurring in 1 per 3200-3400 live births), IS represent a major social and treatment burden. The etiology of IS varies - there are many (>200) different known pathologies resulting in IS and still in about one third of cases there is no obvious reason. With the advancement of genetic analysis, role of certain genes (such as ARX or CDKL5 and others) in IS appears to be important. Current treatment strategies with incomplete efficacy and serious potential adverse effects include adrenocorticotropin (ACTH), corticosteroids (prednisone, prednisolone) and vigabatrin, more recently also a combination of hormones and vigabatrin. Second line treatments include pyridoxine (vitamin B6) and ketogenic diet. Additional treatment approaches use rapamycin, cannabidiol, valproic acid and other anti-seizure medications. Efficacy of these second line medications is variable but usually inferior to hormonal treatments and vigabatrin. Thus, new and effective models of this devastating condition are required for the search of additional treatment options as well as for better understanding the mechanisms of IS. Currently, eight models of IS are reviewed along with the ideas and mechanisms behind these models, drugs tested using the models and their efficacy and usefulness. Etiological variety of IS is somewhat reflected in the variety of the models. However, it seems that for finding precise personalized approaches, this variety is necessary as there is no "one-size-fits-all" approach possible for both IS in particular and epilepsy in general.

Management of Infantile Spasms: An Updated Review

Infantile spasms remain the most challenging of the epileptic encephalopathies of childhood. Infantile spasms are classified as an epileptic encephalopathy, as the adverse cognitive and behavioral burden of the condition is out of proportion to the burden one would expect from the underlying etiology or the accompanying magnetic resonance imaging. The ictal and interictal electroencephalographic (EEG) activity is presumed to contribute to the progressive cerebral dysfunction. In many of these children, the underlying etiology also contributes to the severe mental subnormality and autistic behavior. Though it is the syndromic approach that guides the pediatric epileptologist, it is best to keep in mind that one syndrome may evolve into another in infancy and early childhood. A baby with Ohtahara syndrome may, after 2 to 7 months, begin to have spasms. Lennox-Gastaut syndrome with its typical seizure types and EEG may evolve in a child with infantile spasms.

The unique modalities used in the treatment of infantile spasms make early recognition important. It is, however, also of paramount importance to make an etiological diagnosis as the underlying etiology may be eminently treatable. The treating physician cannot abandon them as wholly “intractable” epilepsy. The excellent response to treatment in the few who just cannot be defined or accurately predicted drives the physician to exercise his brain. Use of the two well-accepted modalities of treatment; vigabatrin and adrenocorticotrophic hormone singly or in combination, oral steroids in high dose, ketogenic diet, the conventional antiepileptic medications, and strategies to target the basic cause have been tried out by various clinicians. Here, we have made an attempt to collate evidence and describe the progress in the management of infantile spasms.

Treatment of infantile spasms

The treatment of infantile spasms is challenging, especially in the context of the following: (1) a severe phenotype with high morbidity and mortality; (2) the urgency of diagnosis and successful early response to therapy; and (3) the paucity of effective, safe, and well-tolerated therapies. Even after initially successful treatment, relapse risk is substantial and the most effective therapies pose considerable risk with long-term administration. In evaluating any treatment for infantile spasms, the key short-term outcome measure is freedom from both epileptic spasms and hypsarrhythmia. In contrast, the most important long-term outcomes are enduring seizure-freedom and measures of intellectual performance in later childhood and adulthood. First-line treatment options-namely hormonal therapy and vigabatrin-display moderate to high efficacy but also exhibit substantial side-effect burdens. Data on efficacy and safety of each class of therapy, as well as the combination of these therapies, are reviewed in detail. Specific hormonal therapies (adrenocorticotropic hormone and various corticosteroids) are contrasted. Those etiologies that prompt specific therapies are reviewed briefly, as are an array of second-line therapies supported by less-compelling data. The ketogenic diet is discussed in greater detail, with a focus on the limitations of numerous available studies that generally suggest that it is efficacious. Special discussion is allocated to cannabidiol-the investigational therapy that has received the most attention, and which is already in use in the form of various artisanal cannabis extracts. Finally, a treatment algorithm reflecting the concepts and controversies discussed in this review is presented.

Efficacy of ketogenic diet for infantile spasms: A systematic review

The aim of this systematic review was to collect and analyze all the RCTs and observational studies investigating the efficacy of ketogenic diet (KD) in infantile spasms (IS) patients after a 1- to 6-month follow-up period, in terms of decrease in seizure frequency of >50% or a seizure-free interval. Moreover, the potential effect of gender, IS etiology, age at onset of IS, and age at start of KD have been investigated. Finally, we evaluated the seizure-free rate at 12 and 24 months of follow-up. In June 2016, a computer search was performed on MedLine (PubMed), EMBASE, and the Cochrane Library. Only, English language studies conducted after 1980 and those reporting in detail the variation in seizure frequency have been selected. Thirteen observational studies (341 patients) were included in the final analysis. A median rate of 64.7% of patients experienced a spasm reduction >50% (IQR: 38.94%). The median spasm-free rate was 34.61% (IQR: 37.94%). IS of unknown etiology seemed to have an increased probability of achieving freedom from seizures (RR: 1.72, 95%CI: 1.18-2.53). Long-time follow-up data revealed a median seizure-free rate of 9.54% (IQR: 18.23%). Although the literature is still lacking in high-quality studies, which could provide a stronger level evidence, our findings suggest a potential benefit of KD for drug-resistant IS patients.

Epileptic spasms - 175 years on: Trying to teach an old dog new tricks

PURPOSE

This text provides an overview of how the condition "infantile spasms" has evolved in the last 175 years.

METHOD

Key references are summarised to assimilate this review.

RESULTS

Infantile spasms, first described by Dr West in 1841, has undergone extensive investigation to understand the pathogenesis, aetiologies, optimal intervention and most likely prognosis for the affected child. The terminology has recently evolved such that the preferred term for the condition is now "epileptic spasms" in recognition of the fact that cases can present outside infancy. The aetiologies are diverse and can be structural, genetic, metabolic or acquired. Increasing numbers of presumed causative genetic mutations are now being identified. The condition is an epileptic encephalopathy such that without adequate control of the clinical seizures and correction of the abnormal EEG, ongoing neurological damage occurs. In some cases neuroregression is inevitable despite intervention. First-line treatments are either hormonal therapies, adrenocortcotrophic hormone or prednisolone, or vigabatrin. In the sub-group of patients with tuberous sclerosis complex, vigabatrin is the preferred treatment. High dose prednisolone may be a more viable option in resource limited settings. Recent research has suggested that combining hormonal therapies with vigabatrin will result in more patients achieving spasm cessation.

CONCLUSIONS

Despite extensive study, the pathogenic mechanisms remain an area of debate and in need of further exploration. The enigma, however, may be explained as the role of resting state and dysfunctional brain networks are elucidated further.