Ketogenic diet restores aberrant cortical motor maps and excitation-to-inhibition imbalance in the BTBR mouse model of autism spectrum disorder

Reversal of Autism Symptoms among Dizygotic Twins through a Personalized Lifestyle and Environmental Modification Approach: A Case Report and Review of the Literature

The prevalence of autism has been increasing at an alarming rate. Even accounting for the expansion of autism spectrum disorder diagnostic (ASD) criteria throughout the 1990's, there has been an over 300% increase in ASD prevalence since the year 2000. The often debilitating personal, familial, and societal sequelae of autism are generally believed to be lifelong. However, there have been several encouraging case reports demonstrating the reversal of autism diagnoses, with a therapeutic focus on addressing the environmental and modifiable lifestyle factors believed to be largely underlying the condition. This case report describes the reversal of autism symptoms among dizygotic, female twin toddlers and provides a review of related literature describing associations between modifiable lifestyle factors, environmental exposures, and various clinical approaches to treating autism. The twins were diagnosed with Level 3 severity ASD "requiring very substantial support" at approximately 20 months of age following concerns of limited verbal and non-verbal communication, repetitive behaviors, rigidity around transitions, and extensive gastrointestinal symptoms, among other common symptoms. A parent-driven, multidisciplinary, therapeutic intervention involving a variety of licensed clinicians focusing primarily on addressing environmental and modifiable lifestyle factors was personalized to each of the twin's symptoms, labs, and other outcome measures. Dramatic improvements were noted within several months in most domains of the twins' symptoms, which manifested in reductions of Autism Treatment Evaluation Checklist (ATEC) scores from 76 to 32 in one of the twins and from 43 to 4 in the other twin. The improvement in symptoms and ATEC scores has remained relatively stable for six months at last assessment. While prospective studies are required, this case offers further encouraging evidence of ASD reversal through a personalized, multidisciplinary approach focusing predominantly on addressing modifiable environmental and lifestyle risk factors.

Diet in treatment of autism spectrum disorders

Altering the diet to treat disease dates to c. 400 BC when starvation was used to reduce seizures in persons with epilepsy. The current diversity of symptomology and mechanisms underlying autism spectrum disorders (ASDs) and a corresponding lack of disorder-specific effective treatments prompts an evaluation of diet as a therapeutic approach to improve symptoms of ASDs. In this review article, we summarize the main findings of nutritional studies in ASDs, with an emphasis on the most common monogenic cause of autism, Fragile X Syndrome (FXS), and the most studied dietary intervention, the ketogenic diet as well as other dietary interventions. We also discuss the gut microbiota in relation to pre- and probiotic therapies and provide insight into future directions that could aid in understanding the mechanism(s) underlying dietary efficacy.

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

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

Seizure susceptibility to various convulsant stimuli in the BTBR mouse model of autism spectrum disorders

Background: Autism spectrum disorders (ASDs) are one of the most severe chronic childhood disorders in terms of prevalence, morbidity, and impact on society. Interestingly, several systematic reviews and meta-analyses documented a bidirectional link between epilepsy and ASD, supporting the hypothesis that both disorders may have common neurobiological pathways. According to this hypothesis, an imbalance of the excitatory/inhibitory (E/I) ratio in several brain regions may represent a causal mechanism underpinning the co-occurrence of these neurological diseases. Methods: To investigate this bidirectional link, we first tested the seizure susceptibility to chemoconvulsants acting on GABAergic and glutamatergic systems in the BTBR mice, in which an imbalance between E/I has been previously demonstrated. Subsequently, we performed the PTZ kindling protocol to study the impact of seizures on autistic-like behavior and other neurological deficits in BTBR mice. Results: We found that BTBR mice have an increased susceptibility to seizures induced by chemoconvulsants impairing GABA_A neurotransmission in comparison to C57BL/6J control mice, whereas no significant difference in seizure susceptibility was observed after administration of AMPA, NMDA, and Kainate. This data suggests that deficits in GABAergic neurotransmission can increase seizure susceptibility in this strain of mice. Interestingly, BTBR mice showed a longer latency in the development of kindling compared to control mice. Furthermore, PTZ-kindling did not influence autistic-like behavior in BTBR mice, whereas it was able to significantly increase anxiety and worsen cognitive performance in this strain of mice. Interestingly, C57BL/6J displayed reduced sociability after PTZ injections, supporting the hypothesis that a tight connection exists between ASD and epilepsy. Conclusion: BTBR mice can be considered a good model to study epilepsy and ASD contemporarily. However, future studies should shed light on the mechanisms underpinning the co-occurrence of these neurological disorders in the BTBR model.

Circadian Responses to Light in the BTBR Mouse

Animals with altered freerunning periods are valuable in understanding properties of the circadian clock. Understanding the relationship between endogenous clock properties, entrainment, and influence of light in terms of parametric and non-parametric models can help us better understand how different populations adapt to external light cycles. Many clinical populations often show significant changes in circadian properties that in turn cause sleep and circadian problems, possibly exacerbating their underlying clinical condition. BTBR T⁺Itpr3^tf/J (BTBR) mice are a model commonly used for the study of autism spectrum disorders (ASD). Adults and adolescents with ASD frequently exhibit profound sleep and circadian disruptions, including increased latency to sleep, insomnia, advanced and delayed sleep phase disorders, and sleep fragmentation. Here, we investigated the circadian phenotype of BTBR mice in freerunning and light-entrained conditions and found that this strain of mice showed noticeably short freerunning periods (~22.75 h). In addition, when compared to C57BL/6J controls, BTBR mice also showed higher levels of activity even though this activity was compressed into a shorter active phase. Phase delays and phase advances to light were significantly larger in BTBR mice. Despite the short freerunning period, BTBR mice exhibited normal entrainment in light-dark cycles and accelerated entrainment to both advanced and delayed light cycles. Their ability to entrain to skeleton photoperiods of 1 min suggests that this entrainment cannot be attributed to masking. Period differences were also correlated with differences in the number of vasoactive intestinal polypeptide–expressing cells in the suprachiasmatic nucleus (SCN). Overall, the BTBR model, with their unique freerunning and entrainment properties, makes an interesting model to understand the underlying circadian clock.

Rescue of histone hypoacetylation and social deficits by ketogenic diet in a Shank3 mouse model of autism

Human genetic sequencing has implicated epigenetic and synaptic aberrations as the most prominent risk factors for autism. Here we show that autistic patients exhibit the significantly lower histone acetylation and elevated HDAC2 expression in prefrontal cortex (PFC). The diminished histone acetylation is also recaptured in an autism mouse model with the deficiency of the Shank3 gene encoding a synaptic scaffolding protein. Treating young (5-week-old) Shank3-deficient mice with a 4-week ketogenic diet, which can act as an endogenous inhibitor of class I HDACs via the major product β-hydroxybutyrate, elevates the level of histone acetylation in PFC neurons. Behavioral assays indicate that ketogenic diet treatment leads to the prolonged rescue of social preference deficits in Shank3-deficient mice. The HDAC downstream target genes encoding NMDA receptor subunits, GRIN2A and GRIN2B, are significantly reduced in PFC of autistic humans. Ketogenic diet treatment of Shank3-deficient mice elevates the transcription and histone acetylation of Grin2a and Grin2b, and restores the diminished NMDAR synaptic function in PFC neurons. These results suggest that the ketogenic diet provides a promising therapeutic strategy for social deficits in autism via the restoration of histone acetylation and gene expression in the brain.

Efficacy and Safety of Diet Therapies in Children With Autism Spectrum Disorder: A Systematic Literature Review and Meta-Analysis

Objective

Autism Spectrum Disorder is a neurodevelopmental disorder, with a rapid increase in recognition over the past decade. Interest in alternative therapies is growing annually, such as dietary therapies including gluten-free and/or casein-free diet, and the ketogenic diet. However, there is no consensus on the efficacy and safety of dietary therapy in children with ASD up to now. This study aimed to assess the efficacy and safety of these diet interventions for children with ASD based on a meta-analysis of global data.

Methods

Seven databases (Cochrane Library, PubMed, EMBASE, Web of Science, VIP, CNKI, and Wanfang) were searched according to the established inclusion criteria, from the inception of the databases to August 18, 2021. The Cochrane Bias risk assessment tool was intended to assess the quality of the included studies. Review Manager 5.4 software was used as an efficacy analysis tool of the included studies, taking the core autistic symptoms and scales of ASD as therapeutic efficacy evaluations.

Results

In total, 7 RCTs with 338 participants were finally obtained. All studies assessed the association between core autistic symptoms and therapeutic diet, showing a statistically significant effect (standard mean difference (SMD) of −0.51, 95% confidence interval (Cl): −0.81 to −0.21), in which two studies which followed the GFD diet reported significant reductions in social behaviors (SMD of−0.41, 95% Cl: −0.75 to −0.06), showing no correlation with the length of the interventions (P < 0.05). Two studies were performed in KD diet suggested a significant effect in core symptoms (SMD of −0.67, 95% Cl: −1.04 to −0.31). No statistically significant changes were observed in the GFCF diet, GFD diet, cognition, communication, and stereotypical behaviors subgroups (all P > 0.05).

Conclusion

The results of a meta-analysis suggest that diet therapies can significantly ameliorate core symptoms of ASD, and GFD diets are conducive to improving social behaviors. Although the results suggest the effectiveness of dietary therapy for ASD, limited by the small sample size of RCTs, more well-designed, and high-quality clinical trials are needed to validate the above conclusions.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021277565.

A ketogenic diet affects brain volume and metabolome in juvenile mice

Ketogenic diet (KD) is a high-fat and low-carbohydrate therapy for medically intractable epilepsy, and its applications in other neurological conditions, including those occurring in children, have been increasingly tested. However, how KD affects childhood neurodevelopment, a highly sensitive and plastic process, is not clear. In this study, we explored structural, metabolic, and functional consequences of a brief treatment of a strict KD (weight ratio of fat to carbohydrate plus protein is approximately 6.3:1) in naive juvenile mice of different inbred strains, using a multidisciplinary approach. Systemic measurements using magnetic resonance imaging revealed that unexpectedly, the volumes of most brain structures in KD-fed mice were about 90% of those in mice of the same strain but fed a standard diet. The reductions in volumes were nonselective, including different regions throughout the brain, the ventricles, and the white matter. The relative volumes of different brain structures were unaltered. Additionally, as KD is a metabolism-based treatment, we performed untargeted metabolomic profiling to explore potential means by which KD affected brain growth and to identify metabolic changes in the brain. We found that brain metabolomic profile was significantly impacted by KD, through both distinct and common pathways in different mouse strains. To explore whether the volumetric and metabolic changes induced by this KD treatment were associated with functional consequences, we recorded spontaneous EEG to measure brain network activity. Results demonstrated limited alterations in EEG patterns in KD-fed animals. In addition, we observed that cortical levels of brain-derived neurotrophic factor (BDNF), a critical molecule in neurodevelopment, did not change in KD-fed animals. Together, these findings indicate that a strict KD could affect volumetric development and metabolic profile of the brain in inbred juvenile mice, while global network activities and BDNF signaling in the brain were mostly preserved. Whether the volumetric and metabolic changes are related to any core functional consequences during neurodevelopment and whether they are also observed in humans need to be further investigated. In addition, our results indicate that certain outcomes of KD are specific to the individual mouse strains tested, suggesting that the physiological profiles of individuals may need to be examined to maximize the clinical benefit of KD.

The potential roles of excitatory-inhibitory imbalances and the repressor element-1 silencing transcription factor in aging and aging-associated diseases

Disruptions to the central excitatory-inhibitory (E/I) balance are thought to be related to aging and underlie a host of neural pathologies, including Alzheimer's disease. Aging may induce an increase in excitatory signaling, causing an E/I imbalance, which has been linked to shorter lifespans in mice, flies, and worms. In humans, extended longevity correlates to greater repression of genes involved in excitatory neurotransmission. The repressor element-1 silencing transcription factor (REST) is a master regulator in neural cells and is believed to be upregulated with senescent stimuli, whereupon it counters hyperexcitability, insulin/insulin-like signaling pathway activity, oxidative stress, and neurodegeneration. This review examines the putative mechanisms that distort the E/I balance with aging and neurodegeneration, and the putative roles of REST in maintaining neuronal homeostasis.

Emerging Role of the Ketogenic Dietary Therapies beyond Epilepsy in Child Neurology

Ketogenic dietary therapies (KDTs) have been in use for refractory paediatric epilepsy for a century now. Over time, KDTs themselves have undergone various modifications to improve tolerability and clinical feasibility, including the Modified Atkins diet (MAD), medium chain triglyceride (MCT) diet and the low glycaemic index treatment (LGIT). Animal and observational studies indicate numerous benefits of KDTs in paediatric neurological conditions apart from their evident benefits in childhood intractable epilepsy, including neurodevelopmental disorders such as autism spectrum disorder, rarer neurogenetic conditions such as Rett syndrome, Fragile X syndrome and Kabuki syndrome, neurodegenerative conditions such as Pelizaeus-Merzbacher disease, and other conditions such as stroke and migraine. A large proportion of the evidence is derived from individual case reports, case series and some small clinical trials, emphasising the vast scope for research in this avenue. The term 'neuroketotherapeutics' has been coined recently to encompass the rapid strides in this field. In the 100^th year of its use for paediatric epilepsy, this review covers the role of the KDTs in non-epilepsy neurological conditions among children.

Ketogenic diets and the nervous system: a scoping review of neurological outcomes from nutritional ketosis in animal studies

OBJECTIVES

Ketogenic diets have reported efficacy for neurological dysfunctions; however, there are limited published human clinical trials elucidating the mechanisms by which nutritional ketosis produces therapeutic effects. The purpose of this present study was to investigate animal models that report variations in nervous system function by changing from a standard animal diet to a ketogenic diet, synthesise these into broad themes, and compare these with mechanisms reported as targets in pain neuroscience to inform human chronic pain trials.

METHODS

An electronic search of seven databases was conducted in July 2020. Two independent reviewers screened studies for eligibility, and descriptive outcomes relating to nervous system function were extracted for a thematic analysis, then synthesised into broad themes.

RESULTS

In total, 170 studies from eighteen different disease models were identified and grouped into fourteen broad themes: alterations in cellular energetics and metabolism, biochemical, cortical excitability, epigenetic regulation, mitochondrial function, neuroinflammation, neuroplasticity, neuroprotection, neurotransmitter function, nociception, redox balance, signalling pathways, synaptic transmission and vascular supply.

DISCUSSION

The mechanisms presented centred around the reduction of inflammation and oxidative stress as well as a reduction in nervous system excitability. Given the multiple potential mechanisms presented, it is likely that many of these are involved synergistically and undergo adaptive processes within the human body, and controlled animal models that limit the investigation to a particular pathway in isolation may reach differing conclusions. Attention is required when translating this information to human chronic pain populations owing to the limitations outlined from the animal research.

Mitochondrial Dysfunction in Autism Spectrum Disorder: Unique Abnormalities and Targeted Treatments

Several lines of evidence implicate mitochondria in the pathophysiology of autism spectrum disorder (ASD). In this review, we outline some of the evidence supporting this notion, as well as discuss novel abnormalities in mitochondrial function that appear to be related to ASD, and treatments that both target mitochondria and have evidence of usefulness in the treatment of ASD in clinical trials. A suspicion of the mitochondrion's involvement in ASD can be traced back to 1985 when lactic acidosis was noted in a subset of children with ASD. A large population-based study in 2007 confirmed this notion and found that a subset of children with ASD (∼4%) could be diagnosed with a definite mitochondrial disease. Further studies suggested that children with ASD and mitochondrial disease may have certain characteristics such as fatigability, gastrointestinal disorders, unusual types of neurodevelopmental regression, seizures/epilepsy, and motor delay. Further research examining biomarkers of mitochondrial dysfunction and electron transport chain activity suggest that abnormalities of mitochondrial function could affect a much higher number of children with ASD, perhaps up to 80%. Recent research has identified a type of dysfunction of mitochondria in which the activity of the electron transport chain is significantly increased. This novel type of mitochondrial dysfunction may be associated with environmental exposures and neurodevelopmental regression. Several treatments that target mitochondria appear to have evidence for use in children with ASD, including cofactors such as L-Carnitine and the ketogenic diet. Although the understanding of the involvement of mitochondria in ASD is evolving, the mitochondrion is clearly a novel molecular target which can be helpful in understanding the etiology of ASD and treatments that may improve function of children with ASD.

The Effects of a Ketogenic Diet on Sensorimotor Function in a Thoracolumbar Mouse Spinal Cord Injury Model

Spinal cord injury and peripheral nerve injuries are traumatic events that greatly impact quality of life. One factor that is being explored throughout patient care is the idea of diet and the role it has on patient outcomes. But the effects of diet following neurotrauma need to be carefully explored in animal models to ensure that they have beneficial effects. The ketogenic diet provides sufficient daily caloric requirements while being potentially neuroprotective and analgesic. In this study, animals were fed a high-fat, low-carbohydrate diet that led to a high concentration of blood ketone that was sustained for as long as the animals were on the diet. Mice fed a ketogenic diet had significantly lower levels of tyrosine and tryptophan, but the levels of other monoamines within the spinal cord remained similar to those of control mice. Mice were fed a standard or ketogenic diet for 7 d before and 28 d following the injury. Our results show that mice hemisected over the T10–T11 vertebrae showed no beneficial effects of being on a ketogenic diet over a 28 d recovery period. Similarly, ligation of the common peroneal and tibial nerve showed no differences between mice fed normal or ketogenic diets. Tests included von Frey, open field, and ladder-rung crossing. We add to existing literature showing protective effects of the ketogenic diet in forelimb injuries by focusing on neurotrauma in the hindlimbs. The results suggest that ketogenic diets need to be assessed based on the type and location of neurotrauma.

Ketogenic therapy in neurodegenerative and psychiatric disorders: From mice to men

Ketogenic diet is a low carbohydrate and high fat diet that has been used for over 100 years in the management of childhood refractory epilepsy. More recently, ketogenic diet has been investigated for a number of metabolic, neurodegenerative and neurodevelopmental disorders. In this comprehensive review, we critically examine the potential therapeutic benefits of ketogenic diet and ketogenic agents on neurodegenerative and psychiatric disorders in humans and translationally valid animal models. The preclinical literature provides strong support for the efficacy of ketogenic diet in a variety of diverse animal models of neuropsychiatric disorders. However, the evidence from clinical studies, while encouraging, particularly in Alzheimer's disease, psychotic and autism spectrum disorders, is limited to case studies and small pilot trials. Firm conclusion on the efficacy of ketogenic diet in psychiatric disorders cannot be drawn due to the lack of randomised, controlled clinical trials. The potential mechanisms of action of ketogenic therapy in these disorders with diverse pathophysiology may include energy metabolism, oxidative stress and immune/inflammatory processes. In conclusion, while ketogenic diet and ketogenic substances hold promise pre-clinically in a variety of neurodegenerative and psychiatric disorders, further studies, particularly randomised controlled clinical trials, are warranted to better understand their clinical efficacy and potential side effects.

Preclinical testing of the ketogenic diet in fragile X mice

The ketogenic diet is highly effective at attenuating seizures in refractory epilepsy, and accumulating evidence in the literature suggests that it may be beneficial in autism. To our knowledge, no one has studied the ketogenic diet in any fragile X syndrome (FXS) model. FXS is the leading known genetic cause of autism. Herein, we tested the effects of chronic ketogenic diet treatment on seizures, body weight, ketone and glucose levels, diurnal activity levels, learning and memory, and anxiety behaviors in Fmr1^KO and littermate control mice as a function of age. The ketogenic diet selectively attenuates seizures in male but not female Fmr1^KO mice and differentially affects weight gain and diurnal activity levels dependent on Fmr1 genotype, sex and age.

Protocol for the Use of the Ketogenic Diet in Preclinical and Clinical Practice

Many age-related diseases are associated with metabolic abnormalities, and dietary interventions may have some benefit in alleviating symptoms or in delaying disease onset. Here, we review the commonly used best practices involved in applications of the ketogenic diet to facilitate its translation into clinical use. The findings reveal that better education of physicians is essential for applying the optimum diet and monitoring its effects in clinical practice. In addition, investigators should carefully consider potential confounding factors prior to commencing studies involving a ketogenic diet. Most importantly, current studies should improve their reporting on ketone levels as well as on the intake of both macro- and micronutrients. Finally, more detailed studies on the mechanism of action are necessary to help identify potential biomarkers for response prediction and monitoring, and to uncover new drug targets to aid the development of novel treatments.

Nutritional interventions for autism spectrum disorder

Autism spectrum disorder (ASD) is an increasingly prevalent neurodevelopmental disorder with considerable clinical heterogeneity. With no cure for the disorder, treatments commonly center around speech and behavioral therapies to improve the characteristic social, behavioral, and communicative symptoms of ASD. Gastrointestinal disturbances are commonly encountered comorbidities that are thought to be not only another symptom of ASD but to also play an active role in modulating the expression of social and behavioral symptoms. Therefore, nutritional interventions are used by a majority of those with ASD both with and without clinical supervision to alleviate gastrointestinal and behavioral symptoms. Despite a considerable interest in dietary interventions, no consensus exists regarding optimal nutritional therapy. Thus, patients and physicians are left to choose from a myriad of dietary protocols. This review, summarizes the state of the current clinical and experimental literature on nutritional interventions for ASD, including gluten-free and casein-free, ketogenic, and specific carbohydrate diets, as well as probiotics, polyunsaturated fatty acids, and dietary supplements (vitamins A, C, B6, and B12; magnesium and folate).

Intergenerational Metabolic Syndrome and Neuronal Network Hyperexcitability in Autism

We review evidence that suggests a role for excessive consumption of energy-dense foods, particularly fructose, and consequent obesity and insulin resistance (metabolic syndrome) in the recent increase in prevalence of autism spectrum disorders (ASD). Maternal insulin resistance, obesity, and diabetes may predispose offspring to ASD by mechanisms involving chronic activation of anabolic cellular pathways and a lack of metabolic switching to ketosis resulting in a deficit in GABAergic signaling and neuronal network hyperexcitability. Metabolic reprogramming by epigenetic DNA and chromatin modifications may contribute to alterations in gene expression that result in ASD. These mechanistic insights suggest that interventions that improve metabolic health such as intermittent fasting and exercise may ameliorate developmental neuronal network abnormalities and consequent behavioral manifestations in ASD.

Motor cortex excitability and inhibitory imbalance in autism spectrum disorder assessed with transcranial magnetic stimulation: a systematic review

Cortical excitation/inhibition (E/I) imbalances contribute to various clinical symptoms observed in autism spectrum disorder (ASD). However, the detailed pathophysiologic underpinning of E/I imbalance remains uncertain. Transcranial magnetic stimulation (TMS) motor-evoked potentials (MEP) are a non-invasive tool for examining cortical inhibition in ASD. Here, we conducted a systematic review on TMS neurophysiology in motor cortex (M1) such as MEPs and short-interval intracortical inhibition (SICI) between individuals with ASD and controls. Out of 538 initial records, we identified six articles. Five studies measured MEP, where four studies measured SICI. There were no differences in MEP amplitudes between the two groups, whereas SICI was likely to be reduced in individuals with ASD compared with controls. Notably, SICI largely reflects GABA(A) receptor-mediated function. Conversely, other magnetic resonance spectroscopy and postmortem methodologies assess GABA levels. The present review demonstrated that there may be neurophysiological deficits in GABA receptor-mediated function in ASD. In conclusion, reduced GABAergic function in the neural circuits could underlie the E/I imbalance in ASD, which may be related to the pathophysiology of clinical symptoms of ASD. Therefore, a novel treatment that targets the neural circuits related to GABA(A) receptor-mediated function in regions involved in the pathophysiology of ASD may be promising.

Effect of Ketogenic Diet on Motor Functions and Daily Living Activities of Children With Multidrug-Resistant Epilepsy: A Prospective Study

AIMS

To investigate the effect of ketogenic diet on motor function and daily living activities in children with epilepsy.

METHODS

A total of 62 children (median age 5.0 years) were enrolled. Motor function was assessed using the Gross Motor Function Measure (GMFM), and daily living activities and cognitive functions were assessed using the Functional Independence Measure (WeeFIM) before treatment and 3, 6, and 12 months after ketogenic diet treatment.

RESULTS

Significant improvement in total GMFM and WeeFIM scores ( P < .001) were found during the 12 months of ketogenic diet treatment. There was a positive correlation between total GMFM scores and WeeFIM scores at baseline (r= 0.792, P = .0001), and at 3 (r= 0.780, P = .0001), 6 (r= 0.744, P = .0001), and 12 months (r= 0.692, P = .0001) of treatment. Both the responder (50 patients, 80.7%) and nonresponder (12 patients, 19.3%) patient groups showed significantly higher GMFM and WeeFIM scores at 12 months of treatment compared to baseline values. A ≥50% reduction in seizure frequency was observed in 77.4%, 72.6%, and 80.7% of the patients after 3, 6, and 12 months of treatment, respectively.

CONCLUSION

Ketogenic diet treatment improves motor functions and daily living activities in children with epilepsy during the 12 months of treatment.

Traumatic Stress Produces Distinct Activations of GABAergic and Glutamatergic Neurons in Amygdala

Posttraumatic stress disorder (PTSD) is an anxiety disorder characterized by intrusive recollections of a severe traumatic event and hyperarousal following exposure to the event. Human and animal studies have shown that the change of amygdala activity after traumatic stress may contribute to occurrences of some symptoms or behaviors of the patients or animals with PTSD. However, it is still unknown how the neuronal activation of different sub-regions in amygdala changes during the development of PTSD. In the present study, we used single prolonged stress (SPS) procedure to obtain the animal model of PTSD, and found that 1 day after SPS, there were normal anxiety behavior and extinction of fear memory in rats which were accompanied by a reduced proportion of activated glutamatergic neurons and increased proportion of activated GABAergic neurons in basolateral amygdala (BLA). About 10 days after SPS, we observed enhanced anxiety and impaired extinction of fear memory with increased activated both glutamatergic and GABAergic neurons in BLA and increased activated GABAergic neurons in central amygdala (CeA). These results indicate that during early and late phase after traumatic stress, distinct patterns of activation of glutamatergic neurons and GABAergic neurons are displayed in amygdala, which may be implicated in the development of PTSD.

Are therapeutic diets an emerging additional choice in autism spectrum disorder management?

BACKGROUND

A nutritional background has been recognized in the pathophysiology of autism and a series of nutritional interventions have been considered as complementary therapeutic options. As available treatments and interventions are not effective in all individuals, new therapies could broaden management options for these patients. Our aim is to provide current literature data about the effect of therapeutic diets on autism spectrum disorder.

DATA SOURCE

A systematic review was conducted by two reviewers independently. Prospective clinical and preclinical studies were considered.

RESULT

Therapeutic diets that have been used in children with autism include ketogenic and gluten/casein-free diet. We were able to identify 8 studies conducted in animal models of autism demonstrating a beneficial effect on neurophysiological and clinical parameters. Only 1 clinical study was found showing improvement in childhood autism rating scale after implementation of ketogenic diet. With regard to gluten/casein-free diet, 4 clinical studies were totally found with 2 of them showing a favorable outcome in children with autism. Furthermore, a combination of gluten-free and modified ketogenic diet in a study had a positive effect on social affect scores. No serious adverse events have been reported.

CONCLUSION

Despite encouraging laboratory data, there is controversy about the real clinical effect of therapeutic diets in patients with autism. More research is needed to provide sounder scientific evidence.

Current nutritional approaches in managing autism spectrum disorder: A review

The link between nutrition and autism spectrum disorder (ASD), which is a complex developmental disorder manifesting itself in significant delays or deviation in interaction and communication, has provided a fresh point of view and signals that nutrition may have a role in the aetiology of ASD, as well as play an active role in treatment by alleviating symptoms.

OBJECTIVE

In this review study aimed at evaluating, with scientific and concrete proof, the current medical nutrition implementations on ASD, existing medical nutrition therapies have been addressed and their effects on ASD symptoms have been discussed in light of current research.

METHODS

We reviewed articles regarding the medical nutritional therapy of autism on current nutritional approaches selected from PubMed, Science Direct, EBSCO, and databases about autism and nutrition.

RESULTS

The research put forward that in individuals with ASD, while gluten-free/casein-free and ketogenic diets, camel milk, curcumin, probiotics, and fermentable foods can play a role in alleviating ASD symptoms, consumption of sugar, additives, pesticides, genetically modified organisms, inorganic processed foods, and hard-to-digest starches may aggravate symptoms.

DISCUSSION

Further prospective controlled trials with large sample sizes are needed before recommendations can be made regarding the ideal ASD diet. This review emphasizes the value of identifying current nutritional approaches specific to individuals with ASD and integrating their effects on symptoms to the conversation and presents suggestions for future research designed to identify medical nutrition therapies targeting this population to better understand the link between ASD and nutrition.

Changes of thyroid hormonal status in patients receiving ketogenic diet due to intractable epilepsy

BACKGROUND

Ketogenic diet (KD), which is high in fat and low in carbohydrates, mimics the metabolic state of starvation and is used therapeutically for pharmacoresistant epilepsy. It is known that generation of triiodothyronine (T3) from thyroxine (T4) decreases during fasting periods. The aim of this study was to evaluate the thyroid function of children receiving KD for at least 1 year due to drug-resistant epilepsy.

METHODS

A total of 120 patients [63 males, 52.5%; mean age 7.3±4.3 years, median interquartile range (IQR): 7.0 (4-10 years)] treated with KD for at least 1 year were enrolled. Seizure control, side effects, and compliance with the diet were recorded, and free T3, free T4, and thyroid-stimulating hormone (TSH) levels were measured at baseline and at post-treatment months 1, 3, 6, and 12. The Mann-Whitney U-test, repeated measures analysis of variance (ANOVA) with post-hoc Bonferroni correction, and logistic regression analysis were used for data analysis.

RESULTS

Hypothyroidism was diagnosed and L-thyroxine medication was initiated for eight, seven and five patients (20 patients in total, 16.7%) at 1, 3, and 6 months of KD therapy, respectively. Logistic regression analysis showed that baseline TSH elevation [odds ratio (OR): 26.91, 95% confidence interval (CI) 6.48-111.76, p<0.001] and female gender (OR: 3.69, 95% CI 1.05-12.97, p=0.042) were independent risk factors for development of hypothyroidism during KD treatment in epileptic children.

CONCLUSIONS

KD causes thyroid malfunction and L-thyroxine treatment may be required. This is the first report documenting the effect of KD treatment on thyroid function. Thyroid function should be monitored regularly in epileptic patients treated with KD.

Ketogenic diet improves behaviors in a maternal immune activation model of autism spectrum disorder

Prenatal factors influence autism spectrum disorder (ASD) incidence in children and can increase ASD symptoms in offspring of animal models. These may include maternal immune activation (MIA) due to viral or bacterial infection during the first trimesters. Unfortunately, regardless of ASD etiology, existing drugs are poorly effective against core symptoms. For nearly a century a ketogenic diet (KD) has been used to treat seizures, and recent insights into mechanisms of ASD and a growing recognition that immune/inflammatory conditions exacerbate ASD risk has increased interest in KD as a treatment for ASD. Here we studied the effects of KD on core ASD symptoms in offspring exposed to MIA. To produce MIA, pregnant C57Bl/6 mice were injected with the viral mimic polyinosinic-polycytidylic acid; after weaning offspring were fed KD or control diet for three weeks. Consistent with an ASD phenotype of a higher incidence in males, control diet-fed MIA male offspring were not social and exhibited high levels of repetitive self-directed behaviors; female offspring were unaffected. However, KD feeding partially or completely reversed all MIA-induced behavioral abnormalities in males; it had no effect on behavior in females. KD-induced metabolic changes of reduced blood glucose and elevated blood ketones were quantified in offspring of both sexes. Prior work from our laboratory and others demonstrate KDs improve relevant behaviors in several ASD models, and here we demonstrate clear benefits of KD in the MIA model of ASD. Together these studies suggest a broad utility for metabolic therapy in improving core ASD symptoms, and support further research to develop and apply ketogenic and/or metabolic strategies in patients with ASD.

The BTBR mouse model of idiopathic autism - Current view on mechanisms

Autism spectrum disorder (ASD) is the most commonly diagnosed neurodevelopmental disorder, with current estimates of more than 1% of affected children across nations. The patients form a highly heterogeneous group with only the behavioral phenotype in common. The genetic heterogeneity is reflected in a plethora of animal models representing multiple mutations found in families of affected children. Despite many years of scientific effort, for the majority of cases the genetic cause remains elusive. It is therefore crucial to include well-validated models of idiopathic autism in studies searching for potential therapeutic agents. One of these models is the BTBR T⁺Itpr3^tf/J mouse. The current review summarizes data gathered in recent research on potential molecular mechanisms responsible for the autism-like behavioral phenotype of this strain.

C57BL/6J bone marrow transplant increases sociability in BTBR T+ Itpr3tf/J mice

Associative studies across a range of neurodevelopmental disorders have revealed a relationship between immune system function and behavioral deficits. These correlations are particularly evident in individuals with autism spectrum disorders (ASD), a developmental disorder characterized by social behavior deficits and noted for its high instances of immune system dysfunction. Mouse models provide a unique opportunity to explore causal links between immune and nervous system function and reveal how changes in these systems alter behavioral profiles. The BTBR T⁺ Itpr3^tf/J (BTBR) mouse strain is characterized by both social behavior impairments and aberrant immune responses, affording the unique opportunity to investigate the causal relationship between behavior and immunity through direct manipulation of these systems. Using bone marrow from the highly social C57BL/6J (C57) mouse strain, BTBR mice were tested for changes in social approach behavior and repetitive grooming following irradiation and bone marrow transplant. BTBR recipient mice treated with allogeneic bone marrow from C57 donor mice, but not syngeneic BTBR bone marrow, displayed increased sociability as measured by the three-chamber social approach task and total time spent social sniffing. In addition, C57 recipient mice given allogeneic bone marrow from BTBR donors showed a significant increase in repetitive grooming behavior. These data provide evidence for a causal relationship between peripheral immune phenotype and social behavior in the BTBR mouse strain and further strengthen and expand on our existing understanding of the role of immune function in behavior.