The ketogenic diet for intractable epilepsy in adults: preliminary results

Ketogenic diet, adenosine, and dopamine in addiction and psychiatry

Adhering to the ketogenic diet can reduce or stop seizures, even when other treatments fail, via mechanism(s) distinct from other available therapies. These results have led to interest in the diet for treating conditions such as Alzheimer's disease, depression and schizophrenia. Evidence points to the neuromodulator adenosine as a key mechanism underlying therapeutic benefits of a ketogenic diet. Adenosine represents a unique and direct link among cell energy, neuronal activity, and gene expression, and adenosine receptors form functional heteromers with dopamine receptors. The importance of the dopaminergic system is established in addiction, as are the challenges of modulating the dopamine system directly. A mediator that could antagonize dopamine's effects would be useful, and adenosine is such a mediator due to its function and location. Studies report that the ketogenic diet improves cognition, sociability, and perseverative behaviors, and might improve depression. Many of the translational opportunities based on the ketogenic diet/adenosine link have come to the fore, including addiction, autism spectrum disorder, painful conditions, and a range of hyperdopaminergic disorders.

Low-carbohydrate and ketogenic diets: a scoping review of neurological and inflammatory outcomes in human studies and their relevance to chronic pain

Dietary restriction of carbohydrate has been demonstrated to be beneficial for nervous system dysfunction in animal models and may be beneficial for human chronic pain. The purpose of this review is to assess the impact of a low-carbohydrate/ketogenic diet on the adult nervous system function and inflammatory biomarkers to inform nutritional research for chronic pain. An electronic database search was carried out in May 2021. Publications were screened for prospective research with dietary carbohydrate intake <130 g per day and duration of ≥2 weeks. Studies were categorised into those reporting adult neurological outcomes to be extracted for analysis and those reporting other adult research outcomes. Both groups were screened again for reported inflammatory biomarkers. From 1548 studies, there were 847 studies included. Sixty-four reported neurological outcomes with 83% showing improvement. Five hundred and twenty-three studies had a different research focus (metabolic n = 394, sport/performance n = 51, cancer n = 33, general n = 30, neurological with non-neuro outcomes n = 12, or gastrointestinal n = 4). The second screen identified sixty-three studies reporting on inflammatory biomarkers, with 71% reporting a reduction in inflammation. The overall results suggest a favourable outcome on the nervous system and inflammatory biomarkers from a reduction in dietary carbohydrates. Both nervous system sensitisation and inflammation occur in chronic pain, and the results from this review indicate it may be improved by low-carbohydrate nutritional therapy. More clinical trials within this population are required to build on the few human trials that have been done.

The Modified Atkins Diet for Epilepsy: Two Decades of an "Alternative" Ketogenic Diet Therapy

In 2003, the first case series of six patients treated with an Atkins diet for epilepsy was published in the journal Neurology. The concept was a simple, outpatient-initiated diet in which ketosis could be maintained by eating high-fat foods while tracking and limiting daily carbohydrate counts based on food ingredient labels. Twenty years later, after dozens of studies encompassing hundreds of patients, including several randomized controlled trials, the Modified Atkins Diet is a proven method of providing ketogenic dietary therapy for epilepsy. It is a diet therapy of choice for adolescents and adults, is being investigated for new-onset epilepsy, and is researched for neurological conditions other than epilepsy. Adverse effects do exist but may be less common than the classic ketogenic diet. This review will cover the history, clinical trials, implementation, current utilization, and future directions of this "alternative" ketogenic diet therapy on its 20-year anniversary.

Difficulties in the implementation of the ketogenic diet in adult patients with refractory epilepsy

BACKGROUND

Ketogenic diet therapies (KDT) are appropriate therapeutic options for pediatric and adult patients with intractable epilepsy. The application of KDT among adult patients with refractory epilepsy is limited compared to children for several reasons, including poor compliance. We present the significant reasons for the lack of adherence to KDT in our adult patients with intractable epilepsy.

METHODS

This study was conducted retrospectively in adult patients with drug-resistant epilepsy who wereofferedand accepted toimplementKDT between 2014 and 2021. Demographic and clinical data were collected via electronic health records. The eventual outcome of KDT results was obtained from the consultant dietitian. The prevalence and reasons for the failure to implement KDT were investigated. We also obtained detailed information about patients who successfully applied the KDT.

RESULTS

A total of 33 patients (18F; median age 28) who wereoffered and accepted to implement KDT were included. Baseline seizure frequency was >4 per week in 49%, and more than half of the patients used >3 anti-seizure medications (ASM). Epilepsy types were temporal in 10 (30%), extratemporal in 10 (30%), generalized in 6 (18%), and unclassified in 7 (22%) patients.Only 3 patients (9%) were able to maintain KDT in the long term. One of them (33%) benefited from this therapy.In the remaining 30 patients, the reasons for failure were inability to contact the dietitian in 5, failure to apply KDT for a particular reason in 7, inappropriate blood test results or any medical/surgical comorbidities in 6, improvement in seizure burden due to change in ASM in 5, still insufficient knowledge of KDT in 3, unresponsiveness to diet due to incorrect implementation in 1 and unidentified reasons in 3 patients.

CONCLUSIONS

A significant percentage of adult patients with refractory seizures failed to use KDTin our study(91%).Strategies to improve compliance and minimize the side effects might increase the number of drug-refractory epilepsy patients who could benefit from this therapy.

Ketogenic diet for epilepsy control and enhancement in adaptive behavior

The Ketogenic Diet (KD) is gaining attention as a management line in childhood drug resistant epilepsy (DRE). The objective of this study was to highlight KD benefits for Ain Shams University (ASU) Children's Hospital patients. This cross-sectional study included all patients at the Ketoclinic of ASU Children's Hospital since it started. Anthropometric measurements and laboratory data were recorded. Chalfont severity score and daily frequency of epileptic attacks were used to evaluate KD efficacy. Vineland test was used to demonstrate the adaptive behavior of a selected group of patients. ASU Children's Hospital Ketoclinic records included 143 patients. During KD therapy, the weight and height/length assessment showed significant increase with significant decrease in the severity of seizures and its frequency. There were no significant changes in the lipid profile of the patients. Vineland test showed significant improvement in the adaptive behavior in 65% of patients. The Ketoclinic data proves that KD is a tolerable, safe, and effective line of therapy for DRE in children without significant negative impact on their anthropometric measurements or lipid profile. Furthermore, the enhancement in adaptive behavior is a promising finding. It is prudent to recommend wider scale studies for longer duration to demonstrate additional cognitive benefits of KD in pediatric age group.

Interventions for ADHD in children & adolescents with epilepsy: A review and decision tree to guide clinicians

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common pediatric epilepsy comorbidities. Treating ADHD in the context of epilepsy can be overwhelming for parents and clinicians. Current frontline treatment for ADHD is stimulant medication. However, some parents of pediatric patients with epilepsy have concerns about adding additional medication to their child's epilepsy regimen and/or about adverse effects of stimulant medication. Non-medication ADHD treatments including psychosocial interventions and ketogenic diet have also shown success in improving ADHD symptoms. Our focused review provides an easy-to-use guide for clinicians on ADHD interventions and combinations of interventions for pediatric patients with epilepsy and ADHD. Our guide includes information from 8 electronic databases for peer-reviewed, English language studies of psychosocial treatments for youth with epilepsy and ADHD. One hundred eight studies were selected based on inclusion criteria (21 systematic reviews, 12 meta-analyses, 8 literature reviews, 6 population surveys, 31 clinical trials, 20 cross-sectional studies, and 10 retrospective reviews). Results indicated that stimulant medication is a frontline treatment for ADHD symptoms in youth with epilepsy, with important caveats and alternatives.

Efficacy of the ketogenic diet in Chinese adults versus children with drug-resistant epilepsy: A pilot study

OBJECTIVE

We compared the efficacy and safety of ketogenic diet (KD) therapy as a treatment for Chinese adults versus children with drug-resistant epilepsy.

METHODS

The classic KD was initiated in 19 adults and 29 children with drug-resistant epilepsy. The KD ratio and the dosage of antiseizure medication (ASM) were delicately modulated by the ketogenic team.

RESULTS

At 12 months after diet initiation, 11 adults (8 on a KD ratio of 3:1 and 3 on a ratio of 2:1) and 20 children (9 on a ketogenic diet ratio of 3:1 and 11 on a ratio of 2:1) remained on the diet. The retention rate for adult KD therapy recipients was 79.0% at 6 months and 57.9% at 12 months after diet initiation, which was not significantly different from the retention rate for children (82.8% at 6 months and 68.9% at 12 months; P > 0.05). The efficacy rate of KD therapy (seizure freedom or ≥50% reduction in seizure frequency) did not significantly differ between adults (63.2%) and children (75.8%, P = 0.517). Alleviation of seizure severity was observed in 68.4% of adults and 63.6% of children who were not seizure free on KD therapy. Antiseizure medication was reduced in 34 out of all 48 individuals at the final follow-up.

CONCLUSION

Our study demonstrated that KD therapy is a safe and effective treatment for Chinese adults as well as children with drug-resistant epilepsy.

Adherence to Low-Carbohydrate Diets in Patients with Diabetes: A Narrative Review

Evidence suggests that low carbohydrate (<130 g/day of carbohydrate) (LCD) and very low carbohydrate, ketogenic diets (typically <50 g/day of carbohydrate) (VLCKD) can be effective tools for managing diabetes given their beneficial effects on weight loss and glycemic control. VLCKD also result in favorable lipid profile changes. However, these beneficial effects can be limited by poor dietary adherence. Cultural, religious, and economic barriers pose unique challenges to achieving nutritional compliance with LCD and VLCKD. We review the various methods for assessing adherence in clinical studies and obstacles posed, as well as potential solutions to these challenges.

Measuring ketone bodies for the monitoring of pathologic and therapeutic ketosis

BACKGROUND

The ketone bodies β-hydroxybutyrate (BOHB) and acetone are generated as a byproduct of the fat metabolism process. In healthy individuals, ketone body levels are ∼0.1 mM for BOHB and ∼1 part per million for breath acetone (BrAce). These levels can increase dramatically as a consequence of a disease process or when used therapeutically for disease treatment. For example, increased ketone body concentration during weight loss is an indication of elevated fat metabolism. Ketone body measurement is relatively inexpensive and can provide metabolic insights to help guide disease management and optimize weight loss.

METHODS

This review of the literature provides metabolic mechanisms and typical concentration ranges of ketone bodies, which can give new insights into these conditions and rationale for measuring ketone bodies.

RESULTS

Diseases such as heart failure and ketoacidosis can affect caloric intake and macronutrient management, which can elevate BOHB 30-fold and BrAce 1000-fold. Other diseases associated with obesity, such as brain dysfunction, cancer, and diabetes, may cause dysfunction because of an inability to use glucose, excessive reliance on glucose, or poor insulin signaling. Elevating ketone body concentrations (e.g., nutritional ketosis) may improve these conditions by forcing utilization of ketone bodies, in place of glucose, for fuel. During weight loss, monitoring ketone body concentration can demonstrate program compliance and can be used to optimize the weight-loss plan.

CONCLUSIONS

The role of ketone bodies in states of pathologic and therapeutic ketosis indicates that accurate measurement and monitoring of BOHB or BrAce will likely improve disease management. Bariatric surgery is examined as a case study for monitoring both types of ketosis.

International Recommendations for the Management of Adults Treated With Ketogenic Diet Therapies

OBJECTIVE

To evaluate current clinical practices and evidence-based literature to establish preliminary recommendations for the management of adults using ketogenic diet therapies (KDTs).

METHODS

A 12-topic survey was distributed to international experts on KDTs in adults consisting of neurologists and dietitians at medical institutions providing KDTs to adults with epilepsy and other neurologic disorders. Panel survey responses were tabulated by the authors to determine the common and disparate practices between institutions and to compare these practices in adults with KDT recommendations in children and the medical literature. Recommendations are based on a combination of clinical evidence and expert opinion regarding management of KDTs.

RESULTS

Surveys were obtained from 20 medical institutions with >2,000 adult patients treated with KDTs for epilepsy or other neurologic disorders. Common side effects reported are similar to those observed in children, and recommendations for management are comparable with important distinctions, which are emphasized. Institutions differ with regard to recommended biochemical assessment, screening, monitoring, and concern for long-term side effects, and further investigation is warranted to determine the optimal clinical management. Differences also exist between screening and monitoring practices among adult and pediatric providers.

CONCLUSIONS

KDTs may be safe and effective in treating adults with drug-resistant epilepsy, and there is emerging evidence supporting the use in other adult neurologic disorders and general medical conditions as well. Therefore, expert recommendations to guide optimal care are critical as well as further evidence-based investigation.

Ciprofloxacin for treatment of drug-resistant epilepsy

PURPOSE

To investigate the efficacy of short-term treatment with ciprofloxacin in alteration of gut microbiota pattern and reduction of seizure frequency in adult patients with drug-resistant epilepsy.

METHODS

In a prospective study, we investigated the effect of a 5-day course of treatment with ciprofloxacin on gut microbiota pattern and seizure frequency of 23 adults with drug-resistant epilepsy. Fecal samples were collected before and after treatment and were analyzed for microbial load and species. Changes in seizure frequency were registered for 12 weeks. Responders were defined as patients who experienced ≥50 % seizure reduction in comparison to baseline. Outcome measures were specified as alteration in fecal microbial burden in days 5-7 and responder rate in 4th and 12th weeks.

RESULTS

The mean baseline frequency of seizures was5.6 ±7.7 per week. All patients were on polytherapy with a mean of 3 ± 1.2 anti-seizure medications. Microbial analysis showed a considerable increase in Bacteroidetes/Firmicutes ratio after treatment. Seizure frequency significantly decreased at the end of first week and the therapeutic effect continued to week 12 (P < 0.001). The responder rate at 4th and 12th weeks were 69.6 % and 73.9 % respectively with a more prominent response in patients with symptomatic generalized epilepsy (P:0.06).

CONCLUSION

Alteration of abnormal gut microbiota pattern by methods such as short-course antibiotic therapy, prescription of probiotics and fecal microbiota transplant might be effective in treatment of drug-resistant epilepsy.

Ketogenic Diet in Cancer Prevention and Therapy: Molecular Targets and Therapeutic Opportunities

Although cancer is still one of the most significant global challenges facing public health, the world still lacks complementary approaches that would significantly enhance the efficacy of standard anticancer therapies. One of the essential strategies during cancer treatment is following a healthy diet program. The ketogenic diet (KD) has recently emerged as a metabolic therapy in cancer treatment, targeting cancer cell metabolism rather than a conventional dietary approach. The ketogenic diet (KD), a high-fat and very-low-carbohydrate with adequate amounts of protein, has shown antitumor effects by reducing energy supplies to cells. This low energy supply inhibits tumor growth, explaining the ketogenic diet's therapeutic mechanisms in cancer treatment. This review highlights the crucial mechanisms that explain the ketogenic diet's potential antitumor effects, which probably produces an unfavorable metabolic environment for cancer cells and can be used as a promising adjuvant in cancer therapy. Studies discussed in this review provide a solid background for researchers and physicians to design new combination therapies based on KD and conventional therapies.

The Role of Metabolism in Migraine Pathophysiology and Susceptibility

Migraine is a highly prevalent and disabling primary headache disorder, however its pathophysiology remains unclear, hindering successful treatment. A number of key secondary headache disorders have headaches that mimic migraine. Evidence has suggested a role of mitochondrial dysfunction and an imbalance between energetic supply and demand that may contribute towards migraine susceptibility. Targeting these deficits with nutraceutical supplementation may provide an additional adjunctive therapy. Neuroimaging techniques have demonstrated a metabolic phenotype in migraine similar to mitochondrial cytopathies, featuring reduced free energy availability and increased metabolic rate. This is reciprocated in vivo when modelling a fundamental mechanism of migraine aura, cortical spreading depression. Trials assessing nutraceuticals successful in the treatment of mitochondrial cytopathies including magnesium, coenzyme q10 and riboflavin have also been conducted in migraine. Although promising results have emerged from nutraceutical trials in patients with levels of minerals or vitamins below a critical threshold, they are confounded by lacking control groups or cohorts that are not large enough to be representative. Energetic imbalance in migraine may be relevant in driving the tissue towards maximum metabolic capacity, leaving the brain lacking in free energy. Personalised medicine considering an individual's deficiencies may provide an approach to ameliorate migraine.

Effects of Ketogenic Dieting on Body Composition, Strength, Power, and Hormonal Profiles in Resistance Training Men

Wilson, JM, Lowery, RP, Roberts, MD, Sharp, MH, Joy, JM, Shields, KA, Partl, JM, Volek, JS, and D'Agostino, DP. Effects of ketogenic dieting on body composition, strength, power, and hormonal profiles in resistance training men. J Strength Cond Res 34(12): 3463-3474, 2020-This study investigated the impact of an isocaloric and isonitrogenous ketogenic diet (KD) versus a traditional western diet (WD) on changes in body composition, performance, blood lipids, and hormonal profiles in resistance-trained athletes. Twenty-five college-aged men were divided into a KD or traditional WD from weeks 1 to 10, with a reintroduction of carbohydrates from weeks 10 to 11, while participating in a resistance training program. Body composition, strength, power, and blood lipid profiles were determined at weeks 0, 10, and 11. A comprehensive metabolic panel and testosterone levels were also measured at weeks 0 and 11. Lean body mass (LBM) increased in both the KD and WD groups (2.4% and 4.4%, p < 0.01) at week 10. However, only the KD group showed an increase in LBM between weeks 10 and 11 (4.8%, p < 0.0001). Finally, fat mass decreased in both the KD (-2.2 ± 1.2 kg) and WD groups (-1.5 ± 1.6 kg). Strength and power increased to the same extent in the WD and KD conditions from weeks 1 to 11. No changes in any serum lipid measures occurred from weeks 1 to 10; however, a rapid reintroduction of carbohydrate from weeks 10 to 11 raised plasma triglyceride levels in the KD group. Total testosterone increased significantly from weeks 0 to 11 in the KD diet (118 ng·dl) as compared to the WD (-36 ng·dl) from pre to post while insulin did not change. The KD can be used in combination with resistance training to cause favorable changes in body composition, performance, and hormonal profiles in resistance-trained men.

Role of a Ketogenic Diet on Body Composition, Physical Health, Psychosocial Well-Being and Sports Performance in Athletes: A Scoping Review

BACKGROUND

Recently, a focus has been placed on investigating the potential benefits of adherence to a ketogenic diet in enhancing body composition, physical health, psychological well-being, and performance of athletes from various sporting disciplines. As the available research is yet to be collated and analyzed in a single review, this scoping review aims to analyze and draw conclusions from the available literature that exists on the efficacy of a ketogenic diet among athletic populations.

METHODS

Several primary research databases and any relevant citation lists were searched to locate appropriate studies for inclusion in this scoping review. Studies that investigated the effects of adherence to a ketogenic diet (KD), defined by a carbohydrate intake of less than 5% of total energy intake, on body composition, physical health, psychological well-being, and performance among an athletic population were included in the review. From 814 articles screened, 12 were identified as meeting the inclusion criteria and were included in the final scoping review.

RESULTS

Adherence to a KD has beneficial effects on body weight and fat mass. Varying effects were identified on physical health with the diet, eliciting positive effects on fat oxidation but potentially deleterious effects on stool microbiota and iron metabolism. Conflicting results were reported regarding the effects of a KD on sporting performance. Benefits were reported regarding athlete well-being following commencement of a KD, but only after week two.

CONCLUSIONS

The results of this scoping review demonstrate that there are both beneficial and detrimental effects associated with adherence to a KD among athletic populations. It is understood that further research is required to make any concrete recommendations regarding a KD to athletes.

A unifying mechanism of ketogenic diet action: The multiple roles of nicotinamide adenine dinucleotide

The ability of a ketogenic diet to treat seizures and render a neuronal network more resistant to strong electrical activity has been observed for a century in clinics and for decades in research laboratories. Alongside ongoing efforts to understand how this therapy works to stop seizures, metabolic health is increasingly appreciated as critical buffer to resisting and recovering from acute and chronic disease. Accordingly, links between metabolism and health, and the broader emerging impact of the ketogenic diet in improving diverse metabolic, immunological and neurological conditions, have served to intensify the search for its key and/or common mechanisms. Here we review diverse evidence for increased levels of NAD⁺, and thus an altered ratio of NAD⁺/NADH, during metabolic therapy with a ketogenic diet. We propose this as a potential unifying mechanism, and highlight some of the evidence linking altered NAD⁺/NADH with reduced seizures and with a range of short and long-term changes associated with the beneficial effects of a ketogenic diet. An increase in NAD⁺/NADH is consistent with multiple lines of evidence and hypotheses, and therefore we suggest that increased NAD⁺ may be a common mechanism underlying beneficial effects of ketogenic diet therapy.

Therapeutic Use of the Ketogenic Diet in Refractory Epilepsy: What We Know and What Still Needs to Be Learned

Ketogenic diet (KD) has been used to treat epilepsy for 100 years. It is a high-fat, low-carbohydrate, and sufficient-protein-for-growth diet that mimics the metabolic changes occurring during starvation. Except for classic KD, its modified counterparts, including modified Atkins diet and low-glycemic-index treatment, have gained grounds to increase palatability and adherence. Strong evidence exists that the KD offers protection against seizures in difficult-to-treat epilepsy and possesses long-lasting anti-epileptic activity, improving long-term disease outcome. The KD can also provide symptomatic and disease-modifying activity in a wide range of neurodegenerative diseases. In an era of highly available new anti-seizure medications (ASMs), the challenge of refractory epilepsy has still not been solved. This metabolic therapy is increasingly considered due to unique mechanisms and turns out to be a powerful tool in the hands of a skillful team. Despite decades of extensive research to explain the mechanism of its efficacy, the precise mechanism of action is to date still largely unknown. The key feature of this successful diet is the fact that energy is derived largely from fat but not from carbohydrates. Consequently, fundamental change occurs regarding the method of energy production that causes alterations in numerous biochemical pathways, thus restoring energetic and metabolic homeostasis of the brain. There are barriers during the use of this special and individualized therapy in many clinical settings worldwide. The aim of this review is to revisit the current state of the art of therapeutic application of KD in refractory epilepsy.

The evolving indications of KD therapy

Despite the rapid increase of clinical and basic-science knowledge on ketogenic diet therapies over the past years, it has not always been easy to determine the adequate indications of this treatment. Over the nearly 100 years of use, from being a last resource in the therapeutic algorithm, the diet has become one of the four main treatments for patients with difficult-to-control epilepsy together with antiepileptic drugs, surgery, and vagus nerve stimulation. The use of the diet has also changed. The current paper will briefly discuss the history of the diet together with a review of the literature regarding its most important indications and how they have evolved. The concept of the importance of defining the type of seizure, type of syndrome, and etiology in the selection of patients and timing of diet initiation has been gaining importance. This paper explores how the indications of the diet changed together with the shifting focus of epilepsy teams towards its use in different types of epilepsy and epilepsy syndromes and according to etiologies and as an alternative option in refractory and superrefractory status epilepticus.

Effectiveness, retention, and safety of modified ketogenic diet in adults with epilepsy at a tertiary-care centre in the UK

With the rising demand for ketogenic diet therapy in adult epilepsy, there is a need for research describing the real-life effectiveness, retention, and safety of relevant services. In this 1-year prospective cohort study we present outcomes of the first 100 referrals for modified ketogenic diet (MKD) at the UK's largest tertiary-care epilepsy centre, where patients received dietetic review up to twice per week. Of the first 100 referrals, 42 (31 females, 11 males; mean age 36.8 [SD ± 11.4 years]) commenced MKD, having used a mean of 4 (SD ± 3) previous antiepileptic drugs. Retention rates were: 60% at 3 months, 43% at 6 months, and 29% at 12 months. 60% of patients reported an improvement in seizure frequency, 38% reported a > 50% reduction, and 13% reported a period of seizure freedom; 30% reported a worsening in seizure frequency at some point during MKD therapy. The most common reasons for discontinuing MKD were side effects and diet restrictiveness. The most common side effects were weight loss, gastrointestinal symptoms and low mood. The likelihood of discontinuing MKD was significantly decreased by experiencing an improvement in seizure frequency (p ≤ 0.001). This study demonstrates that MKD can be effective in adults, although, even with regular dietetic support, retention rates remain low, and periods of worsening seizure frequency are common.

Consumer Reports of "Keto Flu" Associated With the Ketogenic Diet

Background: The ketogenic diet (KD) is a high-fat, low-carbohydrate diet that limits glucose and results in the production of ketones by the liver and their uptake as an alternative energy source by the brain. KD is an evidence-based treatment for intractable epilepsy. KD is also self-administered, with limited evidence of efficacy, for conditions including weight loss, cognitive and memory enhancement, type II diabetes, cancer, neurological and psychiatric disorders. A commonly discussed side effect of KD in media and online forums is “keto flu,” a cluster of transient symptoms generally reported as occurring within the first few weeks of KD. This study aimed to characterize the pattern of symptoms, severity and time course of keto flu as related by users of online forums.

Method: Online forums referring to “keto flu,” “keto-induction,” or “keto-adaptation” in the URL were identified in Google. Passages describing personal experiences of keto flu were categorized manually with reference to pattern of symptoms, severity, time course, and remedies proposed.

Results: The search criteria identified 75 online forums, 43 met inclusion criteria and contained 448 posts from 300 unique users. Seventy-three made more than one post (mean 3.12, range 2–11). Descriptors of personal experience of keto flu, reported by 101 of 300 users, included 256 symptom descriptions involving 54 discrete symptoms. Commonest symptoms were “flu,” headache, fatigue, nausea, dizziness, “brain fog,” gastrointestinal discomfort, decreased energy, feeling faint and heartbeat alterations. Symptom reports peaked in the first and dwindled after 4 weeks. Resolution of keto flu symptoms was reported by eight users between days 3 and 30 (median 4.5, IQR 3–15). Severity of symptoms, reported by 60 users in 40 forums, was categorized as mild (N = 15), moderate (N = 23), or severe (N = 22). Eighteen remedies were proposed by 121 individual users in 225 posts.

Conclusions: Typically, individual posts provided fragmentary descriptions related to the flow of forum conversations. A composite picture emerged across 101 posts describing personally experienced symptoms. User conversations were generally supportive, sharing remedies for keto flu reflecting assumptions of physiological effects of KD.

The ketogenic diet all grown up-Ketogenic diet therapies for adults

The use of ketogenic diet therapies (KDT) in adults has expanded in the last two decades and has been accompanied by a surge of new retrospective as well as prospective studies evaluating its efficacy in adults with epilepsy. In this review article, we will highlight the recent clinical trials and advances in the use of the ketogenic diet therapy (KDT) in adult patients with epilepsy. We will analyze the responder rate in regard to the epilepsy syndrome (focal vs generalized) to identify adults who are optimal to consider for KDT. In addition to its role in treating patients with chronic epilepsy, we will explore the emerging use of the KDT in the critical care setting in adults with refractory and super-refractory status epilepticus as well as other neurologic disorders. Finally, we will discuss special considerations for the use of KDT in adults with epilepsy including its potential long-term effects on bone and cardiovascular health, and its use in pregnancy.

Potential for diet to prevent and remediate cognitive deficits in neurological disorders

The pathophysiology of many neurological disorders involves oxidative stress, neuroinflammation, and mitochondrial dysfunction. There is now substantial evidence that diet can decrease these forms of pathophysiology, and an emerging body of literature relatedly suggests that diet can also prevent or even remediate the cognitive deficits observed in neurological disorders that exhibit such pathology (eg, Alzheimer's disease, multiple sclerosis, age-related cognitive decline, epilepsy). The current review summarizes the emerging evidence in relation to whole diets prominent in the scientific literature-ketogenic, caloric restriction, high polyphenol, and Mediterranean diets-and provides a discussion of the possible underlying neurophysiological mechanisms.

The 'epileptic diet'- ketogenic and/or slow release of glucose intervention: A review

BACKGROUND & AIMS

The ketogenic diet is high in fat content, adequate with respect to protein but low in carbohydrate and designed to provide brain energy as ketone bodies rather than glucose. The consequence is that epilepsy can be managed and endurance (sport) related energy be derived from fat rather than ingested or stored (glycogen) carbohydrate. This review aims to set the diet in context for seizure related intervention, sport and potential modern variants with respect to glucose management - which have many medical (including epilepsy potentially) and activity related applications.

METHODS

The literature was reviewed using relevant data bases (e.g. Pubmed, Science Direct, Web of Science, Wiley on Line Library) and relevant articles were selected to provide historic and contemporary data for the text and associated Tables.

RESULTS

It is clear great health related benefits have been achieved by feeding the ketogenic to individuals subject to seizures where it helps manage the malaise. Sports applications are evident to. Glucose control diets provide health benefits of the ketogenic diet potentially and there is some evidence they are/can be very effective.

CONCLUSIONS

Key to epilepsy and sport performance is the control of blood glucose. The ketogenic diet has proven to be very effective in this regard but now other approaches to control blood glucose ae being evaluated which have advantages over the ketogenic diet. This therapeutic approach of clinical nutrition will undoubtedly move forwards over the next few years in view of the negative aspects of the ketogenic diet.

Do certain subpopulations of adults with drug-resistant epilepsy respond better to modified ketogenic diet treatments? Evaluation based on prior resective surgery, type of epilepsy, imaging abnormalities, and vagal nerve stimulation

OBJECTIVE

Adults with drug-resistant epilepsy (DRE) are among the most challenging to treat. This study assessed whether specific subpopulations of adult patients with refractory epilepsy responded differently to modified ketogenic diet (MKD) therapy.

METHODS

Changes in seizure frequency, severity, and quality of life (QOL) were retrospectively analyzed based on pre-MKD surgical history, type of epilepsy, imaging findings, and vagal nerve stimulation (VNS) history among adults, ≥17 years of age, with DRE, receiving MKD therapy for three months. Additionally, particular attention was made to medication and VNS adjustments.

RESULTS

Responder rates in seizure frequency, severity, and QOL reported among those with prior surgery were 56%, 75%, and 94%, respectively. Among those with focal epilepsy: 57%, 76%, and 76% had improvements in seizure frequency, seizure severity, and QOL, respectively whereas 83% improvement was seen for all three measures in those with generalized epilepsy. Among those with abnormal imaging: just over 50% reported improvements on all measures. For those with VNS, 53%, 63%, and 95% had improvements in seizure frequency, seizure severity, and QOL, respectively. No statistical differences in seizure frequency, severity, or QOL were noted between groups based on prediet surgical history, seizure type, imaging abnormalities, or VNS history. Compared with expected improvement from medication adjustment alone, significant improvement was seen for all groups; notably, the Z-test for proportions for the surgery group, when compared with placebo responder rates at 20%, was 3.6, p < 0.001.

CONCLUSIONS

Modified ketogenic diet therapies are effective in improving seizure frequency, severity, and QOL and may offer the best chance for improvement among those whose seizures have persisted despite surgical intervention and VNS therapy. All types of epilepsy respond to MKDs, and possibly those with generalized epilepsy may respond better.

Seizures and Epilepsy

Epilepsy affects 65 million people worldwide, and is a leading neurologic cause of loss of quality-adjusted life years. The diagnosis of seizures and epilepsy often depends on a careful history, and is supported with electroencephalogram and imaging. First-line treatment of epilepsy includes medical management. Antiepileptic drugs must be chosen with the patient's particular comorbidities in mind. Drug-resistant epilepsy cases should be referred to an epilepsy specialist and may be evaluated for additional medications, epilepsy surgery, neurostimulation, or dietary therapy. When caring for women, providers must take into account needs for contraception or pregnancy safety where applicable.

Cognitive benefits of the ketogenic diet in patients with epilepsy: A systematic overview

The ketogenic diet (KD) has been found to be effective in reducing seizures in patients with treatment-refractory epilepsy. Less attention has been paid to additional cognitive benefits of KD. The aim of the present paper was to provide a comprehensive overview of the studies reporting effects on cognition after KD treatment in adults and children with epilepsy. To address this aim, the clinical literature on cognitive effects of KD in patients with epilepsy was reviewed using a systematic approach. We conclude that using subjective assessments of the patient's experience, cognitive improvements are frequently reported during KD treatment in the domains of alertness, attention, and global cognition. Studies that used objective neuropsychological tests confirmed benefits on alertness but found no improvement in global cognition. There are indications that these improvements are caused by both seizure reduction and direct effects of KD on cognition. The improvements appear to be unrelated to medication reduction, age when KD is started, type of KD, and sleep improvement. The findings in the present overview contribute to a better understanding of the beneficial effects of KD in patients with epilepsy.

Ketogenic Diets for Adult Neurological Disorders

The current review highlights the evidence supporting the use of ketogenic diet therapies in the management of a growing number of neurological disorders in adults. An overview of the scientific literature supporting posited mechanisms of therapeutic efficacy is presented including effects on neurotransmission, oxidative stress, and neuro-inflammation. The clinical evidence supporting ketogenic diet use in the management of adult epilepsy, malignant glioma, Alzheimer's disease, migraine headache, motor neuron disease, and other neurologic disorders is highlighted and reviewed. Lastly, common adverse effects of ketogenic therapy in adults, including gastrointestinal symptoms, weight loss, and transient dyslipidemia are discussed.

Improving compliance in adults with epilepsy on a modified Atkins diet: A randomized trial

PURPOSE

To determine whether use of a ketogenic formula during the first month of the modified Atkins diet (MAD) in adults with drug-resistant epilepsy (DRE) improves seizure reduction and compliance compared to MAD alone.

METHODS

Eighty adults (age ≥18 years) with DRE and ≥4 reliably quantifiable seizures/month were enrolled. All participants were trained to follow a 20 g/day net carbohydrate limit MAD. Patients were randomized to receive one 8-ounce (237 mL) tetrapak of KetoCal^®, a 4:1 ketogenic ratio formula, daily in combination with MAD during the first month (treatment arm) or second month (control/cross-over arm). Patients recorded urine ketones, weight, and seizure frequency and followed up at 1 and 2 months.

RESULTS

By 1 month, 84% of patients achieved ketosis (median of 4-4.5 days). At 1 month, the treatment arm had a significantly higher ketogenic ratio and more patients with a ≥1:1 ketogenic ratio compared to the control arm. There was no difference in median seizure frequency, proportion of responders (≥50% seizure reduction), or median seizure reduction from baseline between groups. However, patients treated with KetoCal^® during the first month were significantly more likely to continue MAD for 6 months or more.

CONCLUSION

Although supplementing MAD with a ketogenic formula in the first month did not increase the likelihood of reducing seizures compared to MAD alone, significantly more adults remained on MAD long-term with this approach. This suggests a potential strategy for encouraging compliance with MAD in adults with DRE.

Potential Synergies of β-Hydroxybutyrate and Butyrate on the Modulation of Metabolism, Inflammation, Cognition, and General Health

The low-carbohydrate high-fat diet (LCHFD), also known as the ketogenic diet, has cycled in and out of popularity for decades as a therapeutic program to treat metabolic syndrome, weight mismanagement, and drug-resistant disorders as complex as epilepsy, cancer, dementia, and depression. Despite the benefits of this diet, health care professionals still question its safety due to the elevated serum ketones it induces and the limited dietary fiber. To compound the controversy, patient compliance with the program is poor due to the restrictive nature of the diet and symptoms related to energy deficit and gastrointestinal adversity during the introductory and energy substrate transition phase of the diet. The studies presented here demonstrate safety and efficacy of the diet including the scientific support and rationale for the administration of exogenous ketone bodies and ketone sources as a complement to the restrictive dietary protocol or as an alternative to the diet. This review also highlights the synergy provided by exogenous ketone, β-hydroxybutyrate (BHB), accompanied by the short chain fatty acid, butyrate (BA) in the context of cellular and physiological outcomes. More work is needed to unveil the molecular mechanisms by which this program provides health benefits.

Ketogenic diet for treatment of intractable epilepsy in adults: A meta-analysis of observational studies

The ketogenic diet (KD) is an effective treatment for children with drug-resistant epilepsy and has been widely used in young children. Adult patients with intractable epilepsy would also benefit from this dietary treatment. However, only a few studies have been published, and the use of the KD in intractable epilepsy in adults has been limited. This meta-analysis summarized the findings of the relevant published studies to identify the efficacy of the KD for the treatment of intractable epilepsy in adults. In this meta-analysis, PubMed, Embase, and Cochrane Library were used for searching studies concerning the effects of the KD and its major subtypes with intractable epilepsy in adults published up to January 10, 2017. The primary outcomes were seizure freedom, seizure reduction by 50% or more, and seizure reduction by <50%. The quality of the methodology of the observational studies was reviewed by using the Newcastle-Ottawa Scale. We identified 402 articles, of which, 16 studies including 338 patients met the inclusion criteria. The results of the meta-analysis showed that the combined efficacy rates of all the symptoms of seizure freedom, seizure reduction by 50% or more, and seizure reduction below 50% in adults with intractable epilepsy were 13%, 53%, and 27%, respectively. The adverse reactions of the KD were mild, whereas low glycemic index diet (LGID) and low-dose fish oil diet (LFOD) may have fewer side effects. Weight loss, high level of low-density lipoprotein, and elevated total cholesterol were most frequent. The meta-analysis indicates that the KD for refractory epilepsy in adults is a well-tolerated treatment and that its side effects are acceptable, which show that the KD is a promising treatment in adult intractable epilepsy. Further research is needed to assess which type of diet or ratio is more effective in the KD treatment.

Ketogenic Diets for Adults With Highly Refractory Epilepsy

The current review highlights the evidence supporting the use of ketogenic diets in the management of drug-resistant epilepsy and status epilepticus in adults. Ketogenic diet variants are compared and advantages and potential side effects of diet therapy are discussed.

The role for ketogenic diets in epilepsy and status epilepticus in adults

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Ketogenic diets offer adjunctive therapy for chronic epilepsy and refractory status epilepticus.

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Studies support feasibility and efficacy of the classic ketogenic diet and its variants in adults.

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Potential complications and side effects of diet therapy are often preventable and manageable.

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Strategies are needed to improve diet adherence.

Ketogenic diet (KD) therapies are high fat, low carbohydrate diets designed to mimic a fasting state. Although studies demonstrate KD’s success in reducing seizures stretching back nearly a century, the last 25 years have seen a resurgence in diet therapy for the management of drug-resistant epilepsy in children as well as adults. With ≥50% seizure reduction efficacy rates in adults of 22–55% for the classic KD and 12–67% for the modified Atkins diet, diet therapy may be in many instances comparable to a trial of an additional anti-epileptic medication and potentially with fewer side effects and other health benefits. Moreover, ketogenic diets offer promising new adjunctive strategies for the treatment of acute status epilepticus in the intensive care setting. Here, we review the efficacy and utility of ketogenic diets for the management of chronic epilepsy and refractory status epilepticus in adults and offer practical guidelines for diet implementation and maintenance.

Muscle PGC-1α is required for long-term systemic and local adaptations to a ketogenic diet in mice

Low-carbohydrate/high-fat (LCHF) diets are increasingly popular dietary interventions for body weight control and as treatment for different pathological conditions. However, the mechanisms of action are still poorly understood, in particular, in long-term administration. Besides liver, brain, and heart, skeletal muscle is one of the major organs involved in the regulation of physiological and pathophysiological ketosis. We assessed the role of the peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) in skeletal muscle of male wild-type control and PGC-1α muscle-specific knockout mice upon 12 wk of LCHF diet feeding. Interestingly, LCHF diet administration increased oxygen consumption in a muscle PGC-1α-dependent manner, concomitant with a blunted transcriptional induction of genes involved in fatty acid oxidation and impairment in exercise performance. These data reveal a new role for muscle PGC-1α in regulating the physiological adaptation to long-term LCHF diet administration.

Metabolic Therapy for Temporal Lobe Epilepsy in a Dish: Investigating Mechanisms of Ketogenic Diet using Electrophysiological Recordings in Hippocampal Slices

The hippocampus is prone to epileptic seizures and is a key brain region and experimental platform for investigating mechanisms associated with the abnormal neuronal excitability that characterizes a seizure. Accordingly, the hippocampal slice is a common in vitro model to study treatments that may prevent or reduce seizure activity. The ketogenic diet is a metabolic therapy used to treat epilepsy in adults and children for nearly 100 years; it can reduce or eliminate even severe or refractory seizures. New insights into its underlying mechanisms have been revealed by diverse types of electrophysiological recordings in hippocampal slices. Here we review these reports and their relevant mechanistic findings. We acknowledge that a major difficulty in using hippocampal slices is the inability to reproduce precisely the in vivo condition of ketogenic diet feeding in any in vitro preparation, and progress has been made in this in vivo/in vitro transition. Thus far at least three different approaches are reported to reproduce relevant diet effects in the hippocampal slices: (1) direct application of ketone bodies; (2) mimicking the ketogenic diet condition during a whole-cell patch-clamp technique; and (3) reduced glucose incubation of hippocampal slices from ketogenic diet–fed animals. Significant results have been found with each of these methods and provide options for further study into short- and long-term mechanisms including Adenosine triphosphate (ATP)-sensitive potassium (K_ATP) channels, vesicular glutamate transporter (VGLUT), pannexin channels and adenosine receptors underlying ketogenic diet and other forms of metabolic therapy.

2-Deoxy-d-glucose enhances tonic inhibition through the neurosteroid-mediated activation of extrasynaptic GABAA receptors

OBJECTIVE

The inhibition of glycolysis exerts potent antiseizure effects, as demonstrated by the efficacy of ketogenic and low-glucose/nonketogenic diets in the treatment of drug-resistant epilepsy. ATP-sensitive potassium (K_ATP ) channels have been initially identified as the main determinant of the reduction of neuronal hyperexcitability. However, a plethora of other mechanisms have been proposed. Herein, we report the ability of 2-deoxy-d-glucose (2-DG), a glucose analog that inhibits glycolytic enzymes, of potentiating γ-aminobutyric acid (GABA)ergic tonic inhibition via neurosteroid-mediated activation of extrasynaptic GABA_A receptors.

METHODS

Acute effects of 2-DG on the ATP-sensitive potassium currents, GABAergic tonic inhibition, firing activity, and interictal events were assessed in hippocampal slices by whole-cell patch-clamp and local field potential recordings of dentate gyrus granule cells.

RESULTS

Acute application of 2-DG activates two distinct outward conductances: a K_ATP channel-mediated current and a bicuculline-sensitive tonic current. The effect of 2-DG on such GABAergic tonic currents was fully prevented by either finasteride or PK11195, which are specific inhibitors of the neurosteroidogenesis pathway acting via different mechanisms. Moreover, the oxidized form of vitamin C, dehydroascorbic acid, known for its ability to induce neurosteroidogenesis, also activated a bicuculline-sensitive tonic current in a manner indistinguishable from that of 2-DG. Finally, we found that the enhancement of K_ATP current by 2-DG primarily regulates intrinsic firing rate of granule cells, whereas the increase of the GABAergic tonic current plays a key role in reducing the frequency of interictal events evoked by treatment of hippocampal slices with the convulsive agent 4-aminopyridine.

SIGNIFICANCE

We demonstrated, for the first time, that 2-DG potentiates the extrasynaptic tonic GABAergic current through activation of neurosteroidogenesis. Such tonic inhibition represents the main conductance responsible for the antiseizure action of this glycolytic inhibitor.

The changing face of dietary therapy for epilepsy

Ketogenic diet is an established and effective non-pharmacologic treatment for drug-resistant epilepsy. Ketogenic diet represents the treatment of choice for GLUT-1 deficiency syndrome and pyruvate dehydrogenase complex deficiency. Infantile spasms, Dravet syndrome and myoclonic-astatic epilepsy are epilepsy syndromes for which ketogenic diet should be considered early in the therapeutic pathway. Recently, clinical indications for ketogenic diet have been increasing, as there is emerging evidence regarding safety and effectiveness. Specifically, ketogenic diet response has been investigated in refractory status epilepticus and encephalopathy with status epilepticus during sleep. New targets in neuropharmacology, such as mitochondrial permeability transition, are being studied and might lead to using it effectively in other neurological diseases. But, inefficient connectivity and impaired ketogenic diet proposal limit ideal availability of this therapeutic option. Ketogenic diet in Italy is not yet considered as standard of care, not even as a therapeutic option for many child neurologists and epileptologists.

CONCLUSIONS

The aim of this review is to revisit ketogenic diet effectiveness and safety in order to highlight its importance in drug-resistant epilepsy and other neurological disorders.

WHAT IS KNOWN

• Ketogenic diet efficacy is now described in large case series, with adequate diet compliance and side effects control. • Ketogenic diet is far from being attempted as a first line therapy. Its availability varies worldwide. What is New: • New pharmacological targets such as mitochondrial permeability transition and new epileptic syndromes and etiologies responding to the diet such as refractory status epilepticus are being pointed out. • Ketogenic diet can function at its best when used as a tailor-made therapy. Fine tuning is crucial.

A ketogenic diet accelerates neurodegeneration in mice with induced mitochondrial DNA toxicity in the forebrain

Mitochondrial genome maintenance plays a central role in preserving brain health. We previously demonstrated accumulation of mitochondrial DNA damage and severe neurodegeneration in transgenic mice inducibly expressing a mutated mitochondrial DNA repair enzyme (mutUNG1) selectively in forebrain neurons. Here, we examine whether severe neurodegeneration in mutUNG1-expressing mice could be rescued by feeding the mice a ketogenic diet, which is known to have beneficial effects in several neurological disorders. The diet increased the levels of superoxide dismutase 2, and mitochondrial mass, enzymes, and regulators such as SIRT1 and FIS1, and appeared to downregulate N-methyl-D-aspartic acid (NMDA) receptor subunits NR2A/B and upregulate γ-aminobutyric acid A (GABA_A) receptor subunits α₁. However, unexpectedly, the ketogenic diet aggravated neurodegeneration and mitochondrial deterioration. Electron microscopy showed structurally impaired mitochondria accumulating in neuronal perikarya. We propose that aggravation is caused by increased mitochondrial biogenesis of generally dysfunctional mitochondria. This study thereby questions the dogma that a ketogenic diet is unambiguously beneficial in mitochondrial disorders.

Establishing an Adult Epilepsy Diet Center: Experience, efficacy and challenges

OBJECTIVES

Over 250 medical centers worldwide offer ketogenic diets to children with epilepsy; however, access to these therapies has been extremely limited for adults until recent years. We examine our 5-year experience creating and implementing a dedicated Adult Epilepsy Diet Center designed to provide adults with epilepsy access to ketogenic diets.

MATERIAL AND METHODS

Outpatients seen at the Johns Hopkins Adult Epilepsy Diet Center from August 2010 thru September 2015 age 18years and older were enrolled in a prospective open-label observational study. Patients that also enrolled in ongoing clinical diet trials were excluded from this study. Participant demographics, diet type, urine and/or serum ketones, laboratory studies, seizure frequency, diet duration, reason for discontinuing diet therapy, and side effects were recorded. A subgroup analysis of participants that met International League Against Epilepsy (ILAE) criteria for drug-resistant epilepsy (DRE) and were treated de novo with a Modified Atkins Diet (MAD) was performed to compare outcomes with the current literature regarding efficacy of other antiseizure treatments for DRE.

RESULTS

Two hundred and twenty-nine adults attended the Adult Epilepsy Diet Center, and 168 met inclusion criteria. Two-thirds (n=113, 67%) were women with an age range of 18-86years at the initial visit. Thirty-five participants (21%, n=133) were already on a therapeutic diet while 79% (n=133) were naïve to diet therapy at the time of the initial visit. Diet-naïve participants were typically prescribed MAD (n=130, 98%), unless unable to intake adequate oral nutrition, in which case they were prescribed KD (n=1) or a combination of oral MAD and ketogenic formula (n=2). Twenty-nine of 130 (22%) participants prescribed MAD elected not to start or were lost to follow-up, and 101 (78%) began MAD. A subgroup analysis was performed on one hundred and six participants naïve to diet therapy that met International League Against Epilepsy criteria for DRE, were able to tolerate oral nutrition, and were prescribed a MAD. Relative to the number of enrolled participants who had reliable follow-up results for a given duration (including those that ultimately elected not to start or were later lost to follow-up), at 3months, 36% of these participants responded (≥50% seizure reduction) to diet therapy, and 16% were seizure-free. At 1year, 30% responded, and 13% were seizure-free. At 4years, 21% responded, and 7% were seizure-free. Hyperlipidemia was the most common side effect (occurring in 39% of screened participants, including those on a therapeutic diet prior to the initial visit). Weight loss was also common (occurring in 19% of all participants treated with a ketogenic diet therapy) yet was often an intended effect.

SIGNIFICANCE

This study, the largest series of adults with epilepsy treated with ketogenic diet therapies to date, provides evidence that ketogenic diets may be feasible, effective, and safe long-term in adults, although long-term adherence was limited and further adequately controlled studies are necessary to determine the efficacy of ketogenic diets in the treatment of adults with epilepsy.

Astrocytes as new targets to improve cognitive functions

Astrocytes are now viewed as key elements of brain wiring as well as neuronal communication. Indeed, they not only bridge the gap between metabolic supplies by blood vessels and neurons, but also allow fine control of neurotransmission by providing appropriate signaling molecules and insulation through a tight enwrapping of synapses. Recognition that astroglia is essential to neuronal communication is nevertheless fairly recent and the large body of evidence dissecting such role has focused on the synaptic level by identifying neuro- and gliotransmitters uptaken and released at synaptic or extrasynaptic sites. Yet, more integrated research deciphering the impact of astroglial functions on neuronal network activity have led to the reasonable assumption that the role of astrocytes in supervising synaptic activity translates in influencing neuronal processing and cognitive functions. Several investigations using recent genetic tools now support this notion by showing that inactivating or boosting astroglial function directly affects cognitive abilities. Accordingly, brain diseases resulting in impaired cognitive functions have seen their physiopathological mechanisms revisited in light of this primary protagonist of brain processing. We here provide a review of the current knowledge on the role of astrocytes in cognition and in several brain diseases including neurodegenerative disorders, psychiatric illnesses, as well as other conditions such as epilepsy. Potential astroglial therapeutic targets are also discussed.

Effects of exogenous ketone supplementation on blood ketone, glucose, triglyceride, and lipoprotein levels in Sprague-Dawley rats

Background

Nutritional ketosis induced by the ketogenic diet (KD) has therapeutic applications for many disease states. We hypothesized that oral administration of exogenous ketone supplements could produce sustained nutritional ketosis (>0.5 mM) without carbohydrate restriction.

Methods

We tested the effects of 28-day administration of five ketone supplements on blood glucose, ketones, and lipids in male Sprague–Dawley rats. The supplements included: 1,3-butanediol (BD), a sodium/potassium β-hydroxybutyrate (βHB) mineral salt (BMS), medium chain triglyceride oil (MCT), BMS + MCT 1:1 mixture, and 1,3 butanediol acetoacetate diester (KE). Rats received a daily 5–10 g/kg dose of their respective ketone supplement via intragastric gavage during treatment. Weekly whole blood samples were taken for analysis of glucose and βHB at baseline and, 0.5, 1, 4, 8, and 12 h post-gavage, or until βHB returned to baseline. At 28 days, triglycerides, total cholesterol and high-density lipoprotein (HDL) were measured.

Results

Exogenous ketone supplementation caused a rapid and sustained elevation of βHB, reduction of glucose, and little change to lipid biomarkers compared to control animals.

Conclusions

This study demonstrates the efficacy and tolerability of oral exogenous ketone supplementation in inducing nutritional ketosis independent of dietary restriction.

Managing drug-resistant epilepsy: challenges and solutions

Despite the development of new antiepileptic drugs (AEDs), ~20%-30% of people with epilepsy remain refractory to treatment and are said to have drug-resistant epilepsy (DRE). This multifaceted condition comprises intractable seizures, neurobiochemical changes, cognitive decline, and psychosocial dysfunction. An ongoing challenge to both researchers and clinicians alike, DRE management is complicated by the heterogeneity among this patient group. The underlying mechanism of DRE is not completely understood. Many hypotheses exist, and relate to both the intrinsic characteristics of the particular epilepsy (associated syndrome/lesion, initial response to AED, and the number and type of seizures prior to diagnosis) and other pharmacological mechanisms of resistance. The four current hypotheses behind pharmacological resistance are the "transporter", "target", "network", and "intrinsic severity" hypotheses, and these are reviewed in this paper. Of equal challenge is managing patients with DRE, and this requires a multidisciplinary approach, involving physicians, surgeons, psychiatrists, neuropsychologists, pharmacists, dietitians, and specialist nurses. Attention to comorbid psychiatric and other diseases is paramount, given the higher prevalence in this cohort and associated poorer health outcomes. Treatment options need to consider the economic burden to the patient and the likelihood of AED compliance and tolerability. Most importantly, higher mortality rates, due to comorbidities, suicide, and sudden death, emphasize the importance of seizure control in reducing this risk. Overall, resective surgery offers the best rates of seizure control. It is not an option for all patients, and there is often a significant delay in referring to epilepsy surgery centers. Optimization of AEDs, identification and treatment of comorbidities, patient education to promote adherence to treatment, and avoidance of triggers should be periodically performed until further insights regarding causative pathology can guide better therapies.

Elemental changes in the hippocampal formation following two different formulas of ketogenic diet: an X-ray fluorescence microscopy study

The main purpose of the following study was the determination of elemental changes occurring within hippocampal formation as a result of high-fat and carbohydrate-restricted ketogenic diet (KD). To realize it, X-ray fluorescence microscopy was applied for topographic and quantitative analysis of P, S, K, Ca, Fe, Cu, Zn and Se in hippocampal formations taken from rats fed with two different KDs and naive controls. The detailed comparisons were done for sectors 1 and 3 of the Ammon's, the dentate gyrus and hilus of dentate gyrus. The results of elemental analysis showed that the KDs induced statistically significant changes in the accumulation of P, K, Ca, Zn and Se in particular areas of hippocampal formation and these alterations strongly depended on the composition of the diets. Much greater influence on the hippocampal areal densities of examined elements was found for the KD which was characterized by a lower content of carbohydrates, higher content of fats and increased proportion of unsaturated fatty acids. The levels of P, K and Zn decreased whilst those of Ca and Se increased as a result of the treatment with the KDs.

Epilepsy: A Spectrum Disorder

Epilepsy, a disorder of unprovoked seizures is a multifaceted disease affecting individuals of all ages with a particular predilection for the very young and old. In addition to seizures, many patients often report cognitive and psychiatric problems associated with both the seizures themselves and its therapy. Epilepsy has numerous etiologies both idiopathic and acquired with a wide range of therapeutic responses. Despite numerous treatments available to control repetitive seizures including medications, diets, immunotherapy, surgery, and neuromodulatory devices, a large percentage of patients continue to suffer the consequences of uncontrolled seizures, which include psychosocial stigma and death.

Effects of a ketogenic diet on hippocampal plasticity in freely moving juvenile rats

Ketogenic diets are low-carbohydrate, sufficient protein, high-fat diets with anticonvulsant activity used primarily as a treatment for pediatric epilepsy. The anticonvulsant mechanism is thought to involve elevating inhibition and/or otherwise limiting excitability in the brain. Such a mechanism, however, might also significantly affect normal brain activity and limit synaptic plasticity, effects that would be important to consider in the developing brain. To assess ketogenic diet effects on synaptic transmission and plasticity, electrophysiological recordings were performed at the perforant path/dentate gyrus synapse in awake, freely-behaving juvenile male rats. Electrodes were implanted 1 week prior to recording. Animals were fed regular chow or a ketogenic diet ad libitum for 3 weeks before recording. Although the ketogenic diet did not significantly alter baseline excitability (assessed by input–output curves) or short-term plasticity (using the paired-pulse ratio), it did reduce the magnitude of long-term potentiation at all poststimulation timepoints out to the last time measured (48 h). The results suggest an effect of ketogenic diet-feeding on the induction magnitude but not the maintenance of long-term potentiation. The lack of effect of the diet on baseline transmission and the paired-pulse ratio suggests a mechanism that limits excitation preferentially in conditions of strong stimulation, consonant with clinical reports in which the ketogenic diet alleviates seizures without a major impact on normal brain activity. Limiting plasticity in a seizure-susceptible network may limit seizure-induced epileptogenesis which may subserve the ongoing benefit of the ketogenic diet in epilepsy.

Efficacy of and patient compliance with a ketogenic diet in adults with intractable epilepsy: a meta-analysis

Background and Purpose

Despite the successful use of a ketogenic diet in pediatric epilepsy, its application in adults has been limited. The aim of this meta-analysis was to summarize the findings of relevant published studies in order to identify the efficacy of and compliance with a ketogenic diet and its main subtypes (i.e., classic ketogenic diet and modified Atkins diet) in adults with intractable epilepsy, and to provide useful information for clinical practice.

Methods

Electronic searches of PubMed, EMBASE, Google Scholar, and the ISI Web of Science were conducted to identify studies of the efficacy of and patient compliance with a ketogenic diet in adults with intractable epilepsy; the included studies were reviewed. Meta-analyses were performed using STATA to determine combined efficacy rates and combined rates of compliance with the ketogenic diet and its main subtypes.

Results

In total, 12 studies qualified for inclusion, and data from 270 patients were evaluated.The results of the meta-analysis revealed combined efficacy rates of all types of ketogenic diet, a classical ketogenic diet, and a modified Atkins diet were 42%, 52%, and 34%, respectively; the corresponding combined compliance rates were 45%, 38%, and 56%.

Conclusions

The results indicate that a ketogenic diet is a promising complementary therapy in adult intractable epilepsy, and that while a classical ketogenic diet may be more effective, adult patients are likely to be less compliant with it than with a modified Atkins diet.

Ketogenic dietary therapies for adults with epilepsy: feasibility and classification of response

Ketogenic dietary therapies are an effective treatment for children with drug-resistant epilepsy. There is currently no high-quality evidence regarding ketogenic dietary therapies in adults, and further research has been recommended. This audit aimed to provide further evidence for the feasibility of dietary treatment for adults and to consider factors that may aid response classification in this population. We evaluated the effectiveness and tolerability of ketogenic dietary therapies in 23 adults with epilepsy attending specialist clinics. Medical notes were used to obtain seizure frequency information and other effects associated with dietary treatment. Individuals who achieved ≥50% seizure reduction at all follow-up points were classified as responders. Response rates, in terms of seizure frequency, were similar to those commonly reported in pediatric cohorts: 9/23 (39%) adults were classified as responders. These responders remained on the diet for at least one year (follow-up: 1-10 years). Other benefits reported by patients, but not quantified, included a reduction in seizure severity and increased alertness and concentration. Such factors often favor continuation of ketogenic dietary therapies despite a <50% seizure reduction. One individual experienced psychosis while following dietary treatment; most commonly reported adverse events were gastrointestinal. Adverse events did not lead to discontinuation of treatment in any cases. Our findings suggest that adults with epilepsy are able to follow ketogenic dietary therapies long-term, and such treatment can lead to seizure reduction. Other aspects besides seizure frequency may be relevant when classifying response in adults, and appropriate ways to quantify these factors should be considered for use in future studies.