Epilepsy in autism

CDC-supported epilepsy surveillance and epidemiologic studies: A review of progress since 1994

To report progress, to identify gaps, and to plan epilepsy surveillance and research activities more effectively, the Centers for Disease Control and Prevention (CDC) Epilepsy Program has summarized findings from selected CDC-supported surveillance and epidemiologic studies about epilepsy from 1994 through 2019. We identified publications supported by CDC funding and publications conducted by the CDC Epilepsy Program alone or with partners. We included only epilepsy surveillance and epidemiologic studies focusing on epilepsy burden, epilepsy-related outcomes, and healthcare utilization. We describe the findings of these studies in the following order: 1)prevalence; 2)incidence; 3)epilepsy-related outcomes by selected demographic characteristics; 4)cysticercosis or neurocysticercosis (NCC); 5)traumatic brain injury (TBI); 6)comorbidity; 7)mortality; 8)access to care; 9)quality of care; and 10) cost. We have characterized these findings in relation to the scope of the first three domains of the 2012 Institute of Medicine report on epilepsy and its relevant first four recommendations. From 1994 through 2019, 76 publications on epilepsy-related epidemiologic and surveillance studies were identified. Over the past 25 years, CDC has expanded community, state, and national surveillance on epilepsy and supported epidemiologic studies by using multiple assessment methods and validated case-ascertainment criteria to identify epilepsy burden, epilepsy-related outcomes, and healthcare utilization in the general population or in population subgroups. Among identified research opportunities, studies on epilepsy incidence and risk factors, mortality, and cost are considered as important surveillance gaps. Other remaining gaps and suggested surveillance strategies are also proposed. Findings from this review may help epilepsy researchers and other stakeholders reference and prioritize future activities for epidemiologic and surveillance studies in epilepsy.

Using phecode analysis to characterize co-occurring medical conditions in autism spectrum disorder

LAY ABSTRACT

People with autism spectrum disorder often have a number of other medical conditions in addition to autism. These can range from constipation to epilepsy. This study uses medical record data to understand how frequently and how long people with autism have to be seen by a medical professional for these other medical conditions. This study confirmed that people with autism often have a number of other medical conditions and that they have to go see a medical professional about those conditions often. We also looked to see if children diagnosed with autism after age 5 years might have different medical conditions compared to children diagnosed earlier. Children diagnosed later had more conditions like asthma, hearing loss, and mood disorders. This work describes how much medical care people with autism get for different medical conditions and the burden of seeking additional medical care for people with autism and their families.

Auxiliary α2δ1 and α2δ3 Subunits of Calcium Channels Drive Excitatory and Inhibitory Neuronal Network Development

VGCCs are multisubunit complexes that play a crucial role in neuronal signaling. Auxiliary α2δ subunits of VGCCs modulate trafficking and biophysical properties of the pore-forming α1 subunit and trigger excitatory synaptogenesis. Alterations in the expression level of α2δ subunits were implicated in several syndromes and diseases, including chronic neuropathic pain, autism, and epilepsy. However, the contribution of distinct α2δ subunits to excitatory/inhibitory imbalance and aberrant network connectivity characteristic for these pathologic conditions remains unclear. Here, we show that α2δ1 overexpression enhances spontaneous neuronal network activity in developing and mature cultures of hippocampal neurons. In contrast, overexpression, but not downregulation, of α2δ3 enhances neuronal firing in immature cultures, whereas later in development it suppresses neuronal activity. We found that α2δ1 overexpression increases excitatory synaptic density and selectively enhances presynaptic glutamate release, which is impaired on α2δ1 knockdown. Overexpression of α2δ3 increases the excitatory synaptic density as well but also facilitates spontaneous GABA release and triggers an increase in the density of inhibitory synapses, which is accompanied by enhanced axonaloutgrowth in immature interneurons. Together, our findings demonstrate that α2δ1 and α2δ3 subunits play distinct but complementary roles in driving formation of structural and functional network connectivity during early development. An alteration in α2δ surface expression during critical developmental windows can therefore play a causal role and have a profound impact on the excitatory-to-inhibitory balance and network connectivity.SIGNIFICANCE STATEMENT The computational capacity of neuronal networks is determined by their connectivity. Chemical synapses are the main interface for transfer of information between individual neurons. The initial formation of network connectivity requires spontaneous electrical activity and the calcium channel-mediated signaling. We found that, in early development, auxiliary α2δ3 subunits of calcium channels foster presynaptic release of GABA, trigger formation of inhibitory synapses, and promote axonal outgrowth in inhibitory interneurons. In contrast, later in development, α2δ1 subunits promote the glutamatergic neurotransmission and synaptogenesis, as well as strongly enhance neuronal network activity. We propose that formation of connectivity in neuronal networks is associated with a concerted interplay of α2δ1 and α2δ3 subunits of calcium channels.

A metabolomics approach to investigate urine levels of neurotransmitters and related metabolites in autistic children

Since recently metabolic abnormalities in autistic children have been associated with ASD disturbs, the aim of this study is to determine the neurotransmitter levels in urine samples of autistic children and to analyse the altered metabolic pathway involved in their production. Thus, ASD-specific urinary metabolomic patterns were explored in 40 ASD children and 40 matched controls using untargeted metabolomics through UHPLC-mass spectrometry (Q-exactive analyser), and by using XCMS Metlin software for data interpretation. Through this new advanced technique, a more considerable number of urinary altered metabolites were recorded in autistic children, than in the previous investigations, which allowed us to collect metabolites involved in neurotransmitter production. In these subjects, a high amount of dopamine was revealed and an increased amount of homovanillic acid, to the detriment of noradrenaline and adrenaline production, as well as MHPG and vanillylmandelic acid, which were found lower. This indicates that the accumulation of dopamine is not due to its greater production, but its lesser biotransformation into noradrenaline, due to the blockage of the dopamine β-hydroxylase enzyme by 4-cresol and vitamin C, both found in high quantities in autistic subjects. Finally, a decreased amount of the active form of vitamin B6, pyridoxal phosphate (P5P), implicated in biotransformation of glutamate into γ-aminobutyric acid (GABA), was also detected, justifying the lower levels of latter. All of these alterations are correlated with a peculiar intestinal microbiome in autistic subjects, supporting the idea of a microbiota-gut-brain axis, then altered levels of neurotransmitters and altered neuronal transmission exist.

Autism: considerations for transitions of care into adulthood

PURPOSE OF REVIEW

The steady rise in number of youth diagnosed with autism spectrum disorder (ASD) has led to the need to examine transition of care considerations specific to ASD. Improved understanding and guidance addressing these needs will allow pediatric and adult providers to work together to optimize social, medical, and occupational outcomes for these patients.

RECENT FINDINGS

Health-care transition is a delicate time when children with ASD outgrow the services of pediatric programs and enter a fragmented healthcare system that is unfamiliar, insufficiently knowledgeable, and underfunded for their needs.

SUMMARY

Increasing autism prevalence and an aging population with autism lend urgency to improve outcomes in children transitioning to adult-care. Research reveals poor consequences in social support, education, vocational training and employment, housing, and healthcare. Specific considerations to address these issues and ensure successful transition from pediatric to adult care are needed.

Next-Generation Sequencing in Korean Children With Autism Spectrum Disorder and Comorbid Epilepsy

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social communication and restricted and repetitive behaviors and interests. Identifying the genetic background may be one of the key features for the future diagnosis and treatment of ASD. With the tremendous development in genetic diagnosis techniques, next-generation sequencing (NGS) can be used to analyze multiple genes simultaneously with a single test in laboratory and clinical settings and is well suited for investigating autism genetics. According to previous studies, there are two types of genetic variants in ASD, rare variants and common variants, and both are important in explaining pathogenesis. In this study, NGS data from 137 participants with ASD were reviewed retrospectively with consideration for comorbid epilepsy. Diagnostic yield was 17.51% (24/137), and pathogenic/likely pathogenic variants were seen more frequently in female participants. Fourteen participants were diagnosed with comorbid epilepsy, six of them had pathogenic/likely pathogenic variants (43%). Genes with variants of unknown significance (VOUS) which have one or more evidence of pathogenicity following the American College of Medical Genetics (ACMG) criteria were also reviewed in both ASD and ASD with comorbid epilepsy groups. We found that most frequently found VOUS genes have previously been reported as genes related to ASD or other developmental disorders. These results suggest that when interpreting the NGS results in the clinical setting, careful observation of VOUS with some pathological evidence might contribute to the discovery of genetic pathogenesis of neurodevelopmental disorders such as ASD and epilepsy.

Autism Spectrum Disorder as a Brain-Gut-Microbiome Axis Disorder

While there are numerous medical comorbidities associated with ASD, gastrointestinal (GI) issues have a significant impact on quality of life for these individuals. Recent findings continue to support the relationship between the gut microbiome and both GI symptoms and behavior, but the heterogeneity within the autism spectrum requires in-depth clinical characterization of these clinical cohorts. Large, diverse, well-controlled studies in this area of research are still needed. Although there is still much to discover about the brain-gut-microbiome axis in ASD, microbially mediated therapies, specifically probiotics and fecal microbiota transplantation have shown promise in the treatment of GI symptoms in ASD, with potential benefit to the core behavioral symptoms of ASD as well. Future research and clinical trials must increasingly consider complex phenotypes in ASD in stratification of large datasets as well as in design of inclusion criteria for individual therapeutic interventions.

Pathogenic POGZ mutation causes impaired cortical development and reversible autism-like phenotypes

Pogo transposable element derived with ZNF domain (POGZ) has been identified as one of the most recurrently de novo mutated genes in patients with neurodevelopmental disorders (NDDs), including autism spectrum disorder (ASD), intellectual disability and White-Sutton syndrome; however, the neurobiological basis behind these disorders remains unknown. Here, we show that POGZ regulates neuronal development and that ASD-related de novo mutations impair neuronal development in the developing mouse brain and induced pluripotent cell lines from an ASD patient. We also develop the first mouse model heterozygous for a de novo POGZ mutation identified in a patient with ASD, and we identify ASD-like abnormalities in the mice. Importantly, social deficits can be treated by compensatory inhibition of elevated cell excitability in the mice. Our results provide insight into how de novo mutations on high-confidence ASD genes lead to impaired mature cortical network function, which underlies the cellular pathogenesis of NDDs, including ASD.

De novo mutations significantly contribute to autism spectrum disorders (ASD). Here, the authors demonstrate that ASD-associated de novo mutations in the POGZ gene, one of a high-confidence ASD gene, lead to ASD-related impaired neuronal development and disrupted mature cortical network function.

Transcriptomics of Gabra4 knockout mice reveals common NMDAR pathways underlying autism, memory, and epilepsy

Autism spectrum disorder (ASD) is a neuronal developmental disorder with impaired social interaction and communication, often with abnormal intelligence and comorbidity with epilepsy. Disturbances in synaptic transmission, including the GABAergic, glutamatergic, and serotonergic systems, are known to be involved in the pathogenesis of this disorder, yet we do not know if there is a common molecular mechanism. As mutations in the GABAergic receptor subunit gene GABRA4 are reported in patients with ASD, we eliminated the Gabra4 gene in mice and found that the Gabra4 knockout mice showed autistic-like behavior, enhanced spatial memory, and attenuated susceptibility to pentylenetetrazol-induced seizures, a constellation of symptoms resembling human high-functioning autism. To search for potential molecular pathways involved in these phenotypes, we performed a hippocampal transcriptome profiling, constructed a hippocampal interactome network, and revealed an upregulation of the NMDAR system at the center of the converged pathways underlying high-functioning autism-like and anti-epilepsy phenotypes.

Autism spectrum disorder: definition, epidemiology, causes, and clinical evaluation

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication and the presence of restricted interests and repetitive behaviors. There have been recent concerns about increased prevalence, and this article seeks to elaborate on factors that may influence prevalence rates, including recent changes to the diagnostic criteria. The authors review evidence that ASD is a neurobiological disorder influenced by both genetic and environmental factors affecting the developing brain, and enumerate factors that correlate with ASD risk. Finally, the article describes how clinical evaluation begins with developmental screening, followed by referral for a definitive diagnosis, and provides guidance on screening for comorbid conditions.

Multidisciplinary treatment plan for challenging behaviors in neurodevelopmental disorders

Among symptoms that patients with neurodevelopmental disorders can exhibit, challenging behaviors (CBs) are some of the more complex to face, both for caregivers and the patients themselves. They are more frequent in individuals with severe autism spectrum disorders and intellectual disability, and during the transition period from late childhood to young adulthood. Here, we offer an overview of the therapeutic approaches proven worthy in managing CB. Topics include nonpharmacologic treatments (such as behavioral and family interventions), drug prescriptions, and specific intensive care for life-threatening situations, including inpatient stay in specialized neurobehavioral units. Then, we focus on rare, complex, and resistant clinical presentations, mainly based on the authors' clinical experience. We propose a multimodal intervention framework for these complex presentations, embracing developmental and dimensional approaches. A case presentation illustrates the proposed framework, with the aim of serving readers and health practitioners that are facing such cases.

Preserved low-level visual gain control in autistic adults

Background: No sensory stimulus is an island entire of itself, the processing of visual inputs is highly influenced by surrounding spatial context. Some accounts of Autism Spectrum Disorder have suggested that the sensory difficulties reported in the condition could arise from differences in contextual modulation of sensory stimuli, specifically problems with gain control mechanisms that regulate incoming sensory information as a function of sensory context. Methods: Here we examined the spatial modulation of visual processing in autistic and neurotypical adults by assessing surround suppression for two low-level visual features: orientation and luminance. We used an established psychophysical task with known neurocomputational correlates and interrogated group differences in suppression magnitude.   Results: We found that the magnitude of surround suppression for both visual features was equivalent in autistic adults and matched neurotypical controls. Additionally, there was no relationship between suppression magnitude and autism symptom severity. Conclusion: These results suggest that for low level visual features, the spatial gain control mechanisms regulating sensory input are preserved. These findings have important theoretical implications for establishing the types of gain control mechanisms that are compromised in autism, and the extent to which there are differences in contextual processing.

Genetic backgrounds have unique seizure response profiles and behavioral outcomes following convulsant administration

Three highly utilized strains of mice, common for preclinical genetic studies, were evaluated for seizure susceptibility and behavioral outcomes common to the clinical phenotypes of numerous psychiatric disorders following repeated low-dose treatment with either a gamma-aminobutyric acid (GABA) receptor antagonist (pentylenetetrazole (PTZ)) or a glutamate agonist (kainic acid (KA)). Effects of strain and treatment were evaluated with classic seizure scoring and a tailored behavior battery focused on behavioral domains common in neuropsychiatric research: learning and memory, social behavior, and motor abilities, as well as seizure susceptibility and/or resistance. Seizure response was induced by a single daily treatment of either PTZ (30 mg/kg, intraperitoneally (i.p.)) or KA (5 mg/kg, i.p.) for 10 days. Pentylenetetrazole-treated FVB/NJ and C57BL/6NJ strains of mice showed strong, clear seizure responses. This also resulted in cognitive and social deficits, and increased susceptibility to a high dose of PTZ. Kainic acid-treated FVB/NJ and C57BL/6NJ strains of mice had a robust seizure response, which resulted in hyperactivity. Pentylenetetrazole-treated C57BL/6J mice demonstrated mild hyperactivity, while KA-treated C57BL/6J displayed cognitive deficits and resistance to a high dose of KA but no social deficits. Overall, a uniquely different seizure response profile was detected in the C57BL/6J strain with few observable instances of seizure response despite repeated convulsant administration by two mechanisms. This work illustrated that differing background genetic strains have unique seizure susceptibility profiles and distinct social and cognitive behavior following PTZ and/or KA treatment and that it is, therefore, necessary to consider strain differences before attributing behavioral phenotypes to gene(s) of interest during preclinical evaluations of genetic mouse models, especially when outcome measures are focused on cognitive and/or social behaviors common to the clinical features of numerous neurological disorders.

Trauma and Autism Spectrum Disorder: Review, Proposed Treatment Adaptations and Future Directions

Empirical investigations of trauma and post-traumatic stress disorder (PTSD) in individuals with autism spectrum disorder (ASD) are lacking despite indications of increased risk for exposure to potentially traumatic events in this population. Research on the treatment of traumatic stress psychopathology in ASD is even more limited and suggests a critical need for guidance in the area of ASD-specific treatment adaptations. The current paper provides preliminary recommendations for adapting current evidenced-based, trauma-specific interventions, specifically trauma-focused cognitive behavioral therapy (TF-CBT), for individuals with ASD based on well-established and evidence-based practices for working with this population. These adaptations highlight the need to incorporate treatment goals related to ASD core symptoms and associated characteristics during treatment targeting traumatic stress symptoms. Future directions are discussed, including the development of instruments measuring trauma reactions in ASD, empirical investigations of modified trauma interventions for children with ASD to evaluate effectiveness, and collaboration between professionals specializing in ASD and trauma/PTSD to advance research and facilitate effective care for this community.

Biomarkers Obtained by Transcranial Magnetic Stimulation of the Motor Cortex in Epilepsy

Epilepsy is associated with numerous neurodevelopmental disorders. Transcranial magnetic stimulation (TMS) of the motor cortex coupled with electromyography (EMG) enables biomarkers that provide measures of cortical excitation and inhibition that are particularly relevant to epilepsy and related disorders. The motor threshold (MT), cortical silent period (CSP), short interval intracortical inhibition (SICI), intracortical facilitation (ICF), and long interval intracortical inhibition (LICI) are among TMS-derived metrics that are modulated by antiepileptic drugs. TMS may have a practical role in optimization of antiepileptic medication regimens, as studies demonstrate dose-dependent relationships between TMS metrics and acute medication administration. A close association between seizure freedom and normalization of cortical excitability with long-term antiepileptic drug use highlights a plausible utility of TMS in measures of anti-epileptic drug efficacy. Finally, TMS-derived biomarkers distinguish patients with various epilepsies from healthy controls and thus may enable development of disorder-specific biomarkers and therapies both within and outside of the epilepsy realm.

Dissecting the genetic basis of comorbid epilepsy phenotypes in neurodevelopmental disorders

Background

Neurodevelopmental disorders (NDDs) such as autism spectrum disorder, intellectual disability, developmental disability, and epilepsy are characterized by abnormal brain development that may affect cognition, learning, behavior, and motor skills. High co-occurrence (comorbidity) of NDDs indicates a shared, underlying biological mechanism. The genetic heterogeneity and overlap observed in NDDs make it difficult to identify the genetic causes of specific clinical symptoms, such as seizures.

Methods

We present a computational method, MAGI-S, to discover modules or groups of highly connected genes that together potentially perform a similar biological function. MAGI-S integrates protein-protein interaction and co-expression networks to form modules centered around the selection of a single “seed” gene, yielding modules consisting of genes that are highly co-expressed with the seed gene. We aim to dissect the epilepsy phenotype from a general NDD phenotype by providing MAGI-S with high confidence NDD seed genes with varying degrees of association with epilepsy, and we assess the enrichment of de novo mutation, NDD-associated genes, and relevant biological function of constructed modules.

Results

The newly identified modules account for the increased rate of de novo non-synonymous mutations in autism, intellectual disability, developmental disability, and epilepsy, and enrichment of copy number variations (CNVs) in developmental disability. We also observed that modules seeded with genes strongly associated with epilepsy tend to have a higher association with epilepsy phenotypes than modules seeded at other neurodevelopmental disorder genes. Modules seeded with genes strongly associated with epilepsy (e.g., SCN1A, GABRA1, and KCNB1) are significantly associated with synaptic transmission, long-term potentiation, and calcium signaling pathways. On the other hand, modules found with seed genes that are not associated or weakly associated with epilepsy are mostly involved with RNA regulation and chromatin remodeling.

Conclusions

In summary, our method identifies modules enriched with de novo non-synonymous mutations and can capture specific networks that underlie the epilepsy phenotype and display distinct enrichment in relevant biological processes. MAGI-S is available at https://github.com/jchow32/magi-s.

Prevalence of Epilepsy and Inter-Ictal Epileptiform Discharges in Children with Autism and Attention-Deficit Hyperactivity Disorder

OBJECTIVE

To study the prevalence of epilepsy and Inter-ictal epileptiform discharges (IED) in children with Autism spectrum disorder (ASD) and Attention-deficit hyperactivity disorder (ADHD), and the factors associated with occurrence of epilepsy in these children.

METHODS

Children between 6 and 12 y attending the Child Development Centre of a tertiary-care institute in India were evaluated for ASD and ADHD as per Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). Childhood Autism Rating Scale was used to assess ASD severity, and Conner's Rating Scales were used to sub-classify children with ADHD. Intelligence quotient was assessed if not assessed in the previous 1 y. History of seizures was taken, and electroencephalography was done in all children. Epilepsy was diagnosed and classified according to International League Against Epilepsy.

RESULTS

Of the 130 children enrolled (90 ASD, 40 ADHD), 56 (43%) had epilepsy and 55 (42.3%) had IED. The proportion of both epilepsy and IED was higher among ASD (both 45.5%) as compared to ADHD (37.5% and 35%), although not statistically significant. Among children with ASD, epilepsy was common in those with severe ASD (P < 0.001), and IED were more common in those with IQ <80 (P = 0.047). There were no significant differences between occurrence of epilepsy/IED and subtypes of ADHD.

CONCLUSIONS

The high prevalence of epilepsy and IED among children with ASD and ADHD emphasizes the need for guidelines for identifying and diagnosing epilepsy in this group. This will ensure appropriate management and improve patient outcomes.

The effect of cannabidiol (CBD) on low-frequency activity and functional connectivity in the brain of adults with and without autism spectrum disorder (ASD)

BACKGROUND

The potential benefits of cannabis and its major non-intoxicating component cannabidiol (CBD) are attracting attention, including as a potential treatment in neurodevelopmental disorders such as autism spectrum disorder (ASD). However, the neural action of CBD, and its relevance to ASD, remains unclear. We and others have previously shown that response to drug challenge can be measured using functional magnetic resonance imaging (fMRI), but that pharmacological responsivity is atypical in ASD.

AIMS

We hypothesized that there would be a (different) fMRI response to CBD in ASD.

METHODS

To test this, task-free fMRI was acquired in 34 healthy men (half with ASD) following oral administration of 600 mg CBD or matched placebo (random order; double-blind administration). The 'fractional amplitude of low-frequency fluctuations' (fALFF) was measured across the whole brain, and, where CBD significantly altered fALFF, we tested if functional connectivity (FC) of those regions was also affected by CBD.

RESULTS

CBD significantly increased fALFF in the cerebellar vermis and the right fusiform gyrus. However, post-hoc within-group analyses revealed that this effect was primarily driven by the ASD group, with no significant change in controls. Within the ASD group only, CBD also significantly altered vermal FC with several of its subcortical (striatal) and cortical targets, but did not affect fusiform FC with other regions in either group.

CONCLUSION

Our results suggest that, especially in ASD, CBD alters regional fALFF and FC in/between regions consistently implicated in ASD. Future studies should examine if this affects the complex behaviours these regions modulate.

Rett Syndrome and Other Neurodevelopmental Disorders Share Common Changes in Gut Microbial Community: A Descriptive Review

In this narrative review, we summarize recent pieces of evidence of the role of microbiota alterations in Rett syndrome (RTT). Neurological problems are prominent features of the syndrome, but the pathogenic mechanisms modulating its severity are still poorly understood. Gut microbiota was recently demonstrated to be altered both in animal models and humans with different neurodevelopmental disorders and/or epilepsy. By investigating gut microbiota in RTT cohorts, a less rich microbial community was identified which was associated with alterations of fecal microbial short-chain fatty acids. These changes were positively correlated with severe clinical outcomes. Indeed, microbial metabolites can play a crucial role both locally and systemically, having dynamic effects on host metabolism and gene expression in many organs. Similar alterations were found in patients with autism and down syndrome as well, suggesting a potential common pathway of gut microbiota involvement in neurodevelopmental disorders.

Stem cell models of human synapse development and degeneration

Many brain disorders exhibit altered synapse formation in development or synapse loss with age. To understand the complexities of human synapse development and degeneration, scientists now engineer neurons and brain organoids from human-induced pluripotent stem cells (hIPSC). These hIPSC-derived brain models develop both excitatory and inhibitory synapses and functional synaptic activity. In this review, we address the ability of hIPSC-derived brain models to recapitulate synapse development and insights gained into the molecular mechanisms underlying synaptic alterations in neuronal disorders. We also discuss the potential for more accurate human brain models to advance our understanding of synapse development, degeneration, and therapeutic responses.

EEG Abnormalities as a Neurophysiological Biomarker of Severity in Autism Spectrum Disorder: A Pilot Cohort Study

To date, the phenotypic significance of EEG abnormalities in patients with ASD is unclear. In a population affected by ASD we aimed to evaluate: the phenotypic characteristics; the prevalence of EEG abnormalities; the potential correlations between EEG abnormalities and behavioral and cognitive variables. Sixty-nine patients with ASD underwent cognitive or developmental testing, language assessment, and adaptive behavior skills evaluation as well as sleep/wake EEG recording. EEG abnormalities were found in 39.13% of patients. EEG abnormalities correlated with autism severity, hyperactivity, anger outbursts, aggression, negative or destructive behavior, motor stereotypies, intellectual disability, language impairment and self-harm. Our findings confirmed that EEG abnormalities are present in the ASD population and correlate with several associated phenotypic features.

Approaches and Limitations in the Investigation of Synaptic Transmission and Plasticity

The numbers and strengths of synapses in the brain change throughout development, and even into adulthood, as synaptic inputs are added, eliminated, and refined in response to ongoing neural activity. A number of experimental techniques can assess these changes, including single-cell electrophysiological recording which offers measurements of synaptic inputs with high temporal resolution. Coupled with electrical stimulation, photoactivatable opsins, and caged compounds, to facilitate fine spatiotemporal control over release of neurotransmitters, electrophysiological recordings allow for precise dissection of presynaptic and postsynaptic mechanisms of action. Here, we discuss the strengths and pitfalls of various techniques commonly used to analyze synapses, including miniature excitatory/inhibitory (E/I) postsynaptic currents, evoked release, and optogenetic stimulation. Together, these techniques can provide multiple lines of convergent evidence to generate meaningful insight into the emergence of circuit connectivity and maturation. A full understanding of potential caveats and alternative explanations for findings is essential to avoid data misinterpretation.

Effects of cannabidiol on brain excitation and inhibition systems; a randomised placebo-controlled single dose trial during magnetic resonance spectroscopy in adults with and without autism spectrum disorder

There is increasing interest in the use of cannabis and its major non-intoxicating component cannabidiol (CBD) as a treatment for mental health and neurodevelopmental disorders, such as autism spectrum disorder (ASD). However, before launching large-scale clinical trials, a better understanding of the effects of CBD on brain would be desirable. Preclinical evidence suggests that one aspect of the polypharmacy of CBD is that it modulates brain excitatory glutamate and inhibitory γ-aminobutyric acid (GABA) levels, including in brain regions linked to ASD, such as the basal ganglia (BG) and the dorsomedial prefrontal cortex (DMPFC). However, differences in glutamate and GABA pathways in ASD mean that the response to CBD in people with and without ASD may be not be the same. To test whether CBD 'shifts' glutamate and GABA levels; and to examine potential differences in this response in ASD, we used magnetic resonance spectroscopy (MRS) to measure glutamate (Glx = glutamate + glutamine) and GABA+ (GABA + macromolecules) levels in 34 healthy men (17 neurotypicals, 17 ASD). Data acquisition commenced 2 h (peak plasma levels) after a single oral dose of 600 mg CBD or placebo. Test sessions were at least 13 days apart. Across groups, CBD increased subcortical, but decreased cortical, Glx. Across regions, CBD increased GABA+ in controls, but decreased GABA+ in ASD; the group difference in change in GABA + in the DMPFC was significant. Thus, CBD modulates glutamate-GABA systems, but prefrontal-GABA systems respond differently in ASD. Our results do not speak to the efficacy of CBD. Future studies should examine the effects of chronic administration on brain and behaviour, and whether acute brain changes predict longer-term response.

Epilepsy and Autism Severity: A Study of 6,975 Children

Epilepsy is known to occur in a higher-than-expected proportion of individuals with autism spectrum disorders (ASDs). Prior studies of this heterogeneous disorder have suggested that intelligence quotient (IQ) may drive this relationship. Because intellectual disability (ID) is, independently of ASD, a risk factor for epilepsy, current literature calls into question the long-understood unique relationship between ASD and epilepsy. Second, data have been unclear about whether developmental regression in ASD is associated with epilepsy. Using two cohorts from an online research registry, totaling 6,975 children with ASD, we examined the independent role of four ASD severity measures in driving the relationship with epilepsy: ID, language impairment, core ASD symptom severity, and motor dysfunction, controlling for two known relevant factors: age and sex. We also examined whether developmental regression and epilepsy have an independent statistical link. All four ASD severity factors showed independent statistical associations with epilepsy in one cohort, and three in the other. ID showed the largest relative risk (RR) in both cohorts. Effect sizes were modest. Regression similarly showed an independent statistical association with epilepsy, but with small effect size. Similar to previous work, ID showed the greatest contribution to RR for epilepsy among children with ASD. However, other ASD severity markers showed statistical associations, demonstrating that the ASD-epilepsy association is not reducible to the effect of ID. Inconsistencies in the literature may be due to underpowered studies, yet moving forward with larger-n studies, clinical significance and scientific relevance may be dictated by effect size and not merely statistical significance. Autism Res 2019, 12: 1251-1259. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Epilepsy is known to occur more often in individuals with autism spectrum disorders (ASDs) than is the case in the general population. The association between ASD and epilepsy is of interest because studying the two disorders in combination may help advance our understanding of genetic, molecular, and cellular mechanisms-as well as therapies-for both. Recent studies have suggested that intelligence quotient (IQ) alone in individuals with ASD may account for the increased prevalence of epilepsy. However, our approach was to look at a range of severity factors relevant to ASD and to look for correlations between each severity factor and epilepsy, within two large samples of children with ASD. In summary, we found that each severity factor-presence of intellectual disability, presence of language atypicalities, ASD-specific symptoms severity, and presence of motor issues-independently predicted a small increased risk for epilepsy, countering the argument that IQ alone is a risk factor. We also examined whether epilepsy is associated with developmental regression. Although severe epilepsy syndromes such as Landau-Kleffner syndrome are known to cause autistic-like symptoms following developmental regression, there is controversy about whether other forms of epilepsy are associated with the more common developmental regression seen in many young children with epilepsy. Indeed, we found a small association between epilepsy and developmental regression.

Human-Derived Brain Models: Windows into Neuropsychiatric Disorders and Drug Therapies

Human-derived neurons and brain organoids have revolutionized our ability to model brain development in a dish. In this review, we discuss the potential for human brain models to advance drug discovery for complex neuropsychiatric disorders. First, we address the advantages of human brain models to screen for new drugs capable of altering CNS activity. Next, we propose an experimental pipeline for using human-derived neurons and brain organoids to rapidly assess drug impact on key events in brain development, including neurite extension, synapse formation, and neural activity. The experimental pipeline begins with automated high content imaging for analysis of neurites, synapses, and neuronal viability. Following morphological examination, multi-well microelectrode array technology examines neural activity in response to drug treatment. These techniques can be combined with high throughput sequencing and mass spectrometry to assess associated transcriptional and proteomic changes. These combined technologies provide a foundation for neuropsychiatric drug discovery and future clinical assessment of patient-specific drug responses.

Autistic spectrum disorder and epilepsy: diagnostic challenges

Introduction: Epilepsy is more frequent in individuals with Autism Spectrum Disorder (ASD) than in the general population; however, its diagnosis is frequently challenging. Areas Covered: We report the current diagnostic criteria for both ASD and epilepsy. We describe the incidence, prevalence, and risk factors for epilepsy in patients with ASD. We then focus on the electro-clinical approach, including the clinical evaluation of cognitive regression. Expert Opinion: A diagnosis of epilepsy should be made based on the International League Against Epilepsy (ILAE) definition. A diagnosis of epilepsy should be established based on a single seizure with electroencephalography (EEG) abnormalities. Considering the high prevalence of EEG abnormalities in children with ASD without epilepsy, EEG should only be performed at epilepsy onset, and more precisely when a clinical interview has confirmed that repetitive paroxysmal events could be seizures. There are still many gaps in our understanding of epilepsy in patients with ASD. It would be of interest to further understand the links, if any, between EEG abnormalities and ASD phenotype. The identification of epilepsy syndromes in ASD would help analyze the possible underlying etiologies, for the administration of more appropriate antiepileptic drugs (AED), and to explain the prognosis to caregivers.

Neurological Diseases With Autism Spectrum Disorder: Role of ASD Risk Genes

Autism spectrum disorder (ASD) is frequently comorbid with other neurological disorders such as intellectual disability (ID) or global development delay (GDD) and epilepsy. The pathogenesis of ASD is complex. So far, studies have identified more than 1000 ASD risk genes. Most of them were also reported to relate with other neurological diseases, and only several of them have been confirmed as pathogenic genes for autism. Little is known about the roles of these risk genes in neurological diseases with ASD. In the present study, we recruited a cohort of 158 neurological disorder probands with 163 variants of 48 ASD risk genes. Of these, 50 individuals (31.6%) were diagnosed with ASD. In the ASD patient subset, we identified several rarely reported candidate genes including DOLK, USH2A, and HUWE1. In a comparison of patients with neurological disorders with and without ASD, we found that ID/GDD was frequently comorbid with ASD whereas epilepsy was more common in the non-ASD group. Statistical analyses of all possible risk factors implicated that variants in synaptic genes, especially non-voltage-gated ion channel genes and in transcriptional and chromosome genes were related to ASD, but none of the investigated environmental factors was. Our results are useful for the future diagnosis and prognosis of patients with neurological disorders and emphasize the utility of genetic screening.

Epilepsy and interictal epileptiform activity in patients with autism spectrum disorders

PURPOSE

The purpose of this study was to determine the prevalence of epilepsy and subclinical epileptiform abnormalities in children with autism spectrum disorder (ASD), and to investigate its effects on core autistic symptoms and adaptive behavior skills.

METHODS

Patients with diagnosis of ASD who met full criteria on Autism Diagnostic Interview-Revised (ADI-R) were included in the study. Adaptive behavior skills were assessed by Vineland Adaptive Behavior Scale-II (VABS-II). Clinical assessment for epilepsy and video electroencephalography (EEG) (v-EEG) examinations during wakefulness and/or sleep were prospectively performed in all patients.

RESULTS

A total of 112 patients with diagnosis of ASD of mean age 6.58 ± 3.72 were included in the study. Based on clinical and v-EEG assessments, three groups of patients were defined: 1) patients with epilepsy (n = 17; 15.2%); 2) patients with epileptiform discharges in absence of clinical seizures (n = 14; 12.5%); 3) patients without epilepsy and without epileptiform discharges (n = 81; 72.3%). There were no significant differences between three groups of patients on ADI-R subscores. Speech development was also not significantly related to epilepsy. There was a slight tendency of the VABS-II motor skills score to be higher in the group of patients with autism without clinical diagnosis of epilepsy and without subclinical epileptiform discharges (p < 0.05) in comparison with the two other groups. According to this tendency, we might claim that patients with higher scores on motor skills could have 0.88 times lower odds for having epileptiform EEG activity.

CONCLUSIONS

According to our results, we were not able to detect differences in the ADI-R between the three populations with ASD, all with unknown etiology. Epilepsy, as well as subclinical epileptic discharges, showed small effects on Motor Skills in patients with autism, and had no effect on adaptive behavior Communication/Socialization/Daily Living Skills.

Neurodevelopmental heterogeneity and computational approaches for understanding autism

In recent years, the emerging field of computational psychiatry has impelled the use of machine learning models as a means to further understand the pathogenesis of multiple clinical disorders. In this paper, we discuss how autism spectrum disorder (ASD) was and continues to be diagnosed in the context of its complex neurodevelopmental heterogeneity. We review machine learning approaches to streamline ASD's diagnostic methods, to discern similarities and differences from comorbid diagnoses, and to follow developmentally variable outcomes. Both supervised machine learning models for classification outcome and unsupervised approaches to identify new dimensions and subgroups are discussed. We provide an illustrative example of how computational analytic methods and a longitudinal design can improve our inferential ability to detect early dysfunctional behaviors that may or may not reach threshold levels for formal diagnoses. Specifically, an unsupervised machine learning approach of anomaly detection is used to illustrate how community samples may be utilized to investigate early autism risk, multidimensional features, and outcome variables. Because ASD symptoms and challenges are not static within individuals across development, computational approaches present a promising method to elucidate subgroups of etiological contributions to phenotype, alternative developmental courses, interactions with biomedical comorbidities, and to predict potential responses to therapeutic interventions.

Epilepsy in Children with Autistic Spectrum Disorder

The comorbidity of autistic spectrum disorder (ASD) and epilepsy has been widely discussed but many questions still remain unanswered. The aim of this study was to establish the occurrence of epilepsy among children with ASD to define the type of epileptic seizures and syndromes, the age of onset of epilepsy, EEG abnormalities, the used antiepileptic drugs and the therapeutic responses for seizures and autistic behavior, as well as to find some correlations between epilepsy and gender, etiology and intellectual disability (ID). A retrospective study of medical files of 59 patients (aged 1–18 years) with ASD during a 5-year period was performed. ASD diagnosis was based on the DSM-5 diagnostic criteria. The patients were examined with a detailed medical history, physical and neurological examination, as well as some additional functional, imaging, laboratory and genetic investigations ASD etiology was syndromic in 9, probable syndromic in 9, and idiopathic in 41 children. ID was established in 90% of ASD children, and epilepsy in 44.4%. The onset of epilepsy prevailed before 7 years of age. The most common seizure types were focal with or without secondary generalization (53.4%). Focal epileptiform EEG abnormalities prevailed. Therapeutic response to seizures was good: 58% were seizure-free, while 27% had >50% seizure reduction but no improvement in autistic behavior. There was no correlation between epilepsy and either occurrence or degree of ID. There was a correlation between the frequency of epileptic seizures and the degree of ID. There was no significant difference among epilepsy rates in different etiologic, gender, and ID groups, probably because of the high percentage of ID and because this was a hospital-based study. Our study showed a significant percentage of epilepsy in ASD population and more than 1/4 were of symptomatic etiology. Those could be managed with specific treatments based on the pathophysiology of the gene defect.

Transient Cognitive Impairment in Epilepsy

Impairments of the dialog between excitation and inhibition (E/I) is commonly associated to neuropsychiatric disorders like autism, bipolar disorders and epilepsy. Moderate levels of hyperexcitability can lead to mild alterations of the EEG and are often associated with cognitive deficits even in the absence of overt seizures. Indeed, various testing paradigms have shown degraded performances in presence of acute or chronic non-ictal epileptiform activity. Evidences from both animal models and the clinics suggest that anomalous activity can cause cognitive deficits by transiently disrupting cortical processing, independently from the underlying etiology of the disease. Here, we will review our understanding of the influence of an abnormal EEG activity on brain computation in the context of the available clinical data and in genetic or pharmacological animal models.

Functional Gastrointestinal Disease in Autism Spectrum Disorder: A Retrospective Descriptive Study in a Clinical Sample

Introduction: Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders with complex multifactorial etiologies. Medical comorbidities are common in ASD and include functional gastrointestinal disorders (fGID), which are reported in 30-70% of patients. In this research study, we aimed to systematically assess the prevalence of gastrointestinal problems in ASD and describe their clinical correlates. Methods: In this retrospective study, we reviewed the medical records of all patients admitted to the Comprehensive Medical Program for ASD (AMITEA) at Gregorio Marañón University General Hospital from January 2012 to December 2015. All patients fulfilled the clinical criteria for ASD (DSM-IV-TR). In addition to fGID, epidemiological and clinical variables were collected at intake. Clinical and demographic features were compared among subjects with and without comorbid gastrointestinal problems. Results: The analyses included all patients with documented information about presence/absence of fGID (n = 845; 95% of patients). Ages ranged from 1 to 53 years (mean = 10.52; SD = 8.92; 80.4% males). At least one fGID was present in 30.5% of patients, constipation being the most prevalent (47.4% of fGID patients); fGID were significantly associated with intellectual disability (ID) (p = 0.017), sleep disorders (p = 0.012), and prescription of psychopharmacological treatment (p = 0.019). Conclusions: Almost one-third of ASD patients in our sample had at least one fGID. The presence of fGID was associated with ID, sleep problems and with behavioral problems (as measured by the prescription of psychotropic drugs). This subsample of ASD patients with fGID deserves particular attention in future research projects, focusing on specific phenotypic characteristics and overlapping biological markers that may underlie both pathologies.

Comorbidity Burden in Adults With Autism Spectrum Disorders and Intellectual Disabilities-A Report From the EFAAR (Frailty Assessment in Ageing Adults With Autism Spectrum and Intellectual Disabilities) Study

Background: Autism spectrum disorder (ASD) is an early-onset and lifelong neurodevelopmental condition frequently associated with intellectual disability (ID). Although emerging studies suggest that ASD is associated with premature ageing and various medical comorbidities, as described for ID, data are scarce. Objectives: To determine the comorbidity burden and its association with distinct clinical presentation in terms of ASD severity, adaptive skills, level of autonomy, and drug exposure in a well-phenotyped sample of individuals with ASD-ID-the EFAAR (Frailty Assessment in Ageing Adults with Autism Spectrum and Intellectual Disabilities) cohort. Methods: A total of 63 adults with ASD-ID, with a mean age of 42.9 ± 15.1 years, were recruited from 2015 to 2017 from nine specialized institutions. They underwent detailed clinical examinations, including screening for comorbidities, ASD severity [Childhood Autism Rating Scale (CARS)], adaptive functioning [Vineland Adaptive Behavior Scale II (VABS-II)], autonomy [activities of daily living (ADLs)], and drug use [polypharmacy and the Drug Burden Index (DBI)]. The comorbidity burden was evaluated using the Cumulative Illness Rating Scale (CIRS-G) and its sub-scores [the severity index (CIRS-SI) and severe comorbidity (CIRS-SC)]. Results: We found a large range of comorbidities, including gastrointestinal disorders and mental and neurological diseases. Overall, 25% of our ASD-ID sample had chronic kidney disease with the associated increased cardiovascular risk factors. The comorbidity burden was high (mean CIRS-G total score of 10.6 ± 4.8), comparable with that observed among patients older than those in our population hospitalized in geriatric departments. Furthermore, the comorbidity burden positively correlated with age, decreased autonomy, and polypharmacy. Conclusion: The severity of the comorbidity burden associated with premature ageing in adults with ASD and ID highlight their crucial need of personalized medical care.

Comprehensive cross-disorder analyses of CNTNAP2 suggest it is unlikely to be a primary risk gene for psychiatric disorders

The contactin-associated protein-like 2 (CNTNAP2) gene is a member of the neurexin superfamily. CNTNAP2 was first implicated in the cortical dysplasia-focal epilepsy (CDFE) syndrome, a recessive disease characterized by intellectual disability, epilepsy, language impairments and autistic features. Associated SNPs and heterozygous deletions in CNTNAP2 were subsequently reported in autism, schizophrenia and other psychiatric or neurological disorders. We aimed to comprehensively examine evidence for the role of CNTNAP2 in susceptibility to psychiatric disorders, by the analysis of multiple classes of genetic variation in large genomic datasets. In this study we used: i) summary statistics from the Psychiatric Genomics Consortium (PGC) GWAS for seven psychiatric disorders; ii) examined all reported CNTNAP2 structural variants in patients and controls; iii) performed cross-disorder analysis of functional or previously associated SNPs; and iv) conducted burden tests for pathogenic rare variants using sequencing data (4,483 ASD and 6,135 schizophrenia cases, and 13,042 controls). The distribution of CNVs across CNTNAP2 in psychiatric cases from previous reports was no different from controls of the database of genomic variants. Gene-based association testing did not implicate common variants in autism, schizophrenia or other psychiatric phenotypes. The association of proposed functional SNPs rs7794745 and rs2710102, reported to influence brain connectivity, was not replicated; nor did predicted functional SNPs yield significant results in meta-analysis across psychiatric disorders at either SNP-level or gene-level. Disrupting CNTNAP2 rare variant burden was not higher in autism or schizophrenia compared to controls. Finally, in a CNV mircroarray study of an extended bipolar disorder family with 5 affected relatives we previously identified a 131kb deletion in CNTNAP2 intron 1, removing a FOXP2 transcription factor binding site. Quantitative-PCR validation and segregation analysis of this CNV revealed imperfect segregation with BD.

This large comprehensive study indicates that CNTNAP2 may not be a robust risk gene for psychiatric phenotypes.

Genetic mutations that disrupt both copies of the CNTNAP2 gene lead to severe disease, characterized by profound intellectual disability, epilepsy, language difficulties and autistic traits, leading to the hypothesis that this gene may also be involved in autism given some overlapping clinical features with this disease. Indeed, several large DNA deletions affecting one of the two copies of CNTNAP2 were found in some patients with autism, and later also in patients with schizophrenia, bipolar disorder, ADHD and epilepsy, suggesting that this gene was implicated in several psychiatric or neurologic diseases. Other studies considered genetic sequence variations that are common in the general population, and suggested that two such sequence variations in CNTNAP2 predispose to psychiatric diseases by influencing the functionality and connectivity of the brain. To better understand the involvement of CNTNAP2 in risk of mental illness, we performed several genetic analyses using a series of large publicly available or in-house datasets, comprising many thousands of patients and controls. Furthermore, we report the deletion of one copy of CNTNAP2 in two patients with bipolar disorder and one unaffected relative from an extended family where five relatives were affected with this condition. Despite the previous consideration of CNTNAP2 as a strong candidate gene for autism or schizophrenia, we show little evidence across multiple classes of DNA variation, that CNTNAP2 is likely to play a major role in risk of psychiatric diseases.

Individual differences in sensory sensitivity: A synthesizing framework and evidence from normal variation and developmental conditions

For some people, simple sensory stimuli (e.g., noises, patterns) may reliably evoke intense and aversive reactions. This is common in certain clinical groups (e.g., autism) and varies greatly in the neurotypical population. This paper critically evaluates the concept of individual differences in sensory sensitivity, explores its possible underlying neurobiological basis, and presents a roadmap for future research in this area. A distinction is made between subjective sensory sensitivity (self-reported symptoms); neural sensory sensitivity (the degree of neural activity induced by sensory stimuli); and behavioral sensory sensitivity (detection and discrimination of sensory stimuli). Whereas increased subjective and neural sensory sensitivity are assumed to increase together, the status of behavioral sensory sensitivity depends on the extent to which the increased neural activity is linked to signal or noise. A signal detection framework is presented that offers a unifying framework for exploring sensory sensitivity across different conditions. The framework is discussed, in more concrete terms, by linking it to four existing theoretical accounts of atypical sensory sensitivity (not necessarily mutually exclusive): increased excitation-to-inhibition ratio; predictive coding; increased neural noise; and atypical brain connectivity.

The role of reduced expression of fragile X mental retardation protein in neurons and increased expression in astrocytes in idiopathic and syndromic autism (duplications 15q11.2-q13)

Fragile X syndrome (FXS), caused by lack of fragile X mental retardation protein (FMRP), is associated with a high prevalence of autism. The deficit of FMRP reported in idiopathic autism suggests a mechanistic overlap between FXS and autism. The overall goal of this study is to detect neuropathological commonalities of FMRP deficits in the brains of people with idiopathic autism and with syndromic autism caused by dup15q11.2-q13 (dup15). This study tests the hypothesis based on our preliminary data that both idiopathic and syndromic autism are associated with brain region-specific deficits of neuronal FMRP and structural changes of the affected neurons. This immunocytochemical study revealed neuronal FMRP deficits and shrinkage of deficient neurons in the cerebral cortex, subcortical structures, and cerebellum in subjects with idiopathic and dup(15)/autism. Neuronal FMRP deficit coexists with surprising infiltration of the brains of autistic children and adults with FMRP-positive astrocytes known to be typical only for the fetal and short postnatal periods. In the examined autistic subjects, these astrocytes selectively infiltrate the border between white and gray matter in the cerebral and cerebellar cortex, the molecular layer of the cortex, part of the amygdala and thalamus, central cerebellar white matter, and dentate nucleus. Astrocyte pathology results in an additional local loss of FMRP in neurons and their shrinkage. Neuronal deficit of FMRP and shrinkage of affected neurons in structures free of FMRP-positive astrocytes and regions infiltrated with FMRP-expressing astrocytes appear to reflect mechanistic, neuropathological, and functional commonalities of FMRP abnormalities in FXS and autism spectrum disorder. Autism Res 2018, 11: 1316-1331. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Immunocytochemistry reveals a deficit of fragile X mental retardation protein (FMRP) in neurons of cortical and subcortical brain structures but increased FMRP expression in astrocytes infiltrating gray and white matter. The detected shrinkage of FMRP-deficient neurons may provide a mechanistic explanation of reported neuronal structural and functional changes in autism. This study contributes to growing evidence of mechanistic commonalities between fragile X syndrome and autism spectrum disorder.

Effects of SYN1Q555X mutation on cortical gray matter microstructure

A new Q555X mutation on the SYN1 gene was recently found in several members of a family segregating dyslexia, epilepsy, and autism spectrum disorder. To describe the effects of this mutation on cortical gray matter microstructure, we performed a surface-based group study using novel diffusion and quantitative multiparametric imaging on 13 SYN1Q555X mutation carriers and 13 age- and sex-matched controls. Specifically, diffusion kurtosis imaging (DKI) and neurite orientation and dispersion and density imaging (NODDI) were used to analyze multi-shell diffusion data and obtain parametric maps sensitive to tissue structure, while quantitative metrics sensitive to tissue composition (T1, T2* and relative proton density [PD]) were obtained from a multi-echo variable flip angle FLASH acquisition. Results showed significant microstructural alterations in several regions usually involved in oral and written language as well as dyslexia. The most significant changes in these regions were lowered mean diffusivity and increased fractional anisotropy. This study is, to our knowledge, the first to successfully use diffusion imaging and multiparametric mapping to detect cortical anomalies in a group of subjects with a well-defined genotype linked to language impairments, epilepsy and autism spectrum disorder (ASD).

Therapeutic use of carbohydrate-restricted diets in an autistic child; a case report of clinical and 18FDG PET findings

The ketogenic diet (KD) is a high-fat, adequate-protein, and low-carbohydrate diet that has been used successfully in the treatment of refractory epilepsies for almost 100 years. There has been accumulating evidence to show that the KD may provide a therapeutic benefit in autism spectrum disorders, albeit by a yet-unknown mechanism. We report a case of a 6-year-old patient with high-functioning autism and subclinical epileptic discharges who responded poorly to several behavioural and psychopharmacological treatments. The patient was subsequently placed on the KD due to significant glucose hypometabolism in the brain as revealed by an 18FDG PET. As soon as one month after starting the KD, the patient's behavior and intellect improved (in regard to hyperactivity, attention span, abnormal reactions to visual and auditory stimuli, usage of objects, adaptability to changes, communication skills, fear, anxiety, and emotional reactions); these improvements continued until the end of the observation period at 16 months on the KD. The 18FDG PET, measured at 12 months on the KD, revealed that 18F-FDG uptake decreased markedly and diffusely in the whole cerebral cortex with a relatively low reduction in basal ganglia in comparison to the pre-KD assessment. It warrants further investigation if the 18FDG PET imaging could serve as a biomarker in identifying individuals with autism who might benefit from the KD due to underlying abnormalities related to glucose hypometabolism.

Heterogeneity of Cell Surface Glutamate and GABA Receptor Expression in Shank and CNTN4 Autism Mouse Models

Autism spectrum disorder (ASD) refers to a large set of neurodevelopmental disorders, which have in common both repetitive behavior and abnormalities in social interactions and communication. Interestingly, most forms of ASD have a strong genetic contribution. However, the molecular underpinnings of this disorder remain elusive. The SHANK3 gene (and to a lesser degree SHANK2) which encode for the postsynaptic density (PSD) proteins SHANK3/SHANK2 and the CONTACTIN 4 gene which encodes for the neuronal glycoprotein CONTACTIN4 (CNTN4) exhibit mutated variants which are associated with ASD. Like many of the other genes associated with ASD, both SHANKs and CNTN4 affect synapse formation and function and are therefore related to the proper development and signaling capability of excitatory and inhibitory neuronal networks in the adult mammal brain. In this study, we used mutant/knock-out mice of Shank2 (Shank2^−/−), Shank3 (Shank3αβ^−/−), and Cntn4 (Cntn4^−/−) as ASD-models to explore whether these mice share a molecular signature in glutamatergic and GABAergic synaptic transmission in ASD-related brain regions. Using a biotinylation assay and subsequent western blotting we focused our analysis on cell surface expression of several ionotropic glutamate and GABA receptor subunits: GluA1, GluA2, and GluN1 were analyzed for excitatory synaptic transmission, and the α1 subunit of the GABA_A receptor was analyzed for inhibitory synaptic transmission. We found that both Shank2^−/− and Shank3αβ^−/− mice exhibit reduced levels of several cell surface glutamate receptors in the analyzed brain regions—especially in the striatum and thalamus—when compared to wildtype controls. Interestingly, even though Cntn4^−/− mice also show reduced levels of some cell surface glutamate receptors in the cortex and hippocampus, increased levels of cell surface glutamate receptors were found in the striatum. Moreover, Cntn4^−/− mice do not only show brain region-specific alterations in cell surface glutamate receptors but also a downregulation of cell surface GABA receptors in several of the analyzed brain regions. The results of this study suggest that even though mutations in defined genes can be associated with ASD this does not necessarily result in a common molecular phenotype in surface expression of glutamatergic and GABAergic receptor subunits in defined brain regions.

Autistic traits in epilepsy models: Why, when and how?

Autism spectrum disorder (ASD) is a common comorbidity of epilepsy and seizures and/or epileptiform activity are observed in a significant proportion of ASD patients. Current research also implies that autistic traits can be observed to a various degree in mice and rats with seizures. This suggests that there are shared mechanisms in both ASD and epilepsy syndromes. Here, we first review the standard, validated methods used to assess autistic traits in animal models as well as their limitations with regards to epilepsy models. We then discuss two of the potential pathological processes that could be shared between ASD and epilepsy. We first focus on functional implications of neuroinflammation including changes to excitable networks mediated by inflammatory regulators. Finally we examine mechanisms at the cellular and network level involved in neuronal excitability, timing and network coordination that may directly lead to behavioral disturbances present in both epilepsy and ASD. This mini-review summarizes the work first presented at an Investigators Workshop at the 2016 American Epilepsy Society meeting.

Two-Year Follow-up of Isolated Epileptiform Discharges in Autism: An Endophenotypic Biomarker?

CONTEXT

A significant subset of autistic children exhibit abnormal isolated epileptiform discharges (IEDs) in the absence of clinical epilepsy. The etiological significance of such IEDs is under much debate.

AIMS

The aim is to study the relationship between IEDs with risk factors, clinical severity, behavioral problems, and social-quotient and follow-up for the occurrence of new seizures.

SETTINGS AND DESIGN

This study was a prospective double-blind comparative study of autistic children with and without IEDs.

SUBJECTS AND METHODS

All autistic children attending Child Psychiatry Department of tertiary care postgraduate teaching hospital in April 2013 were included in the study. Electroencephalography, risk factors, and clinical severity were assessed. The same cohort of 72 children was followed for 2 years and reassessed.

STATISTICAL ANALYSIS USED

Independent sample t-test, Chi-square test, Pearson correlation, and linear by linear association were the statistical methods used.

RESULTS

Twenty-four (42%) of the followed up sample exhibited IEDs. 10.52% had converted to clinical seizures within the follow-up period. While there was no difference between risk factors and age at diagnosis between the IED and non-IED groups, there was a significant difference between disease severity, behavioral problems and social quotient between the groups.

CONCLUSIONS

IED in a subgroup of autistic children point to more severe illness, severe behavioral problems, and severe social impairment over a 2-year follow-up period. Can IED be considered a neurobehavioral endophenotype in autism?

An investigation of the association between seizures, autism symptomology, and developmental functioning in young children

OBJECTIVE

The aim of the present study was to explore whether a history of seizures was associated with autism symptom severity and developmental functioning in young children.

METHODS

Autism symptom severity and developmental functioning were compared between children with and without a history or seizures who either had atypical development or met criteria for autism spectrum disorder (ASD) based on review of records by a licensed clinical psychologist.

RESULTS

Parents of children who met criteria for ASD reported lower levels of autism symptomology when the child had a history of seizures, while the opposite trend was found for children with atypical development. Participants without ASD or seizures had greater developmental functioning than the other groups.

CONCLUSION

The present study emphasizes the need for early identification and diagnosis of both ASD and seizure disorders, as timely intervention for these two conditions may be related to improved outcomes for young children.

A cross-syndrome cohort comparison of sleep disturbance in children with Smith-Magenis syndrome, Angelman syndrome, autism spectrum disorder and tuberous sclerosis complex

Background

Sleep disturbance is common in children with neurodevelopmental disorders, with high rates identified in children with Smith-Magenis syndrome (SMS), Angelman syndrome (AS), autism spectrum disorder (ASD) and tuberous sclerosis complex (TSC). Phenotypic sleep profiles for these groups may implicate different pathways to sleep disturbance. At present, cross-group comparisons that might elucidate putative phenotypic sleep characteristics are limited by measurement differences between studies. In this study, a standardised questionnaire was administered across groups affording comparison of the prevalence and profile of sleep disturbance between groups and contrast to chronologically age-matched typically developing (TD) peers.

Methods

The modified version of Simonds and Parraga’s sleep questionnaire, adapted for use in children with intellectual disabilities, was employed to assess sleep disturbance profiles in children aged 2–15 years with SMS (n = 26), AS (n = 70), ASD (n = 30), TSC (n = 20) and a TD contrast group (n = 47). Associations between sleep disturbance and age, obesity, health conditions and overactivity/impulsivity were explored for each neurodevelopmental disorder group.

Results

Children with SMS displayed severe night waking (81%) and early morning waking (73%). In contrast, children with ASD experienced difficulties with sleep onset (30%) and sleep maintenance (43%). Fewer children with ASD (43%) and AS (46%) experienced severe night waking compared to children with SMS (both p < .01). Higher sleep-disordered breathing scores were identified for children with SMS (p < .001) and AS (p < .001) compared to the TD group. Sleep disturbance in children with AS and TSC was associated with poorer health. Children experiencing symptoms indicative of gastro-oesophageal reflux had significantly higher sleep-disordered breathing scores in the AS, SMS and ASD groups (all p < .01). A number of associations between overactivity, impulsivity, gastro-oesophageal reflux, age and sleep disturbance were found for certain groups.

Conclusions

These data reveal syndrome-specific profiles of sleep disturbance. The divergent associations between sleep parameters and person characteristics, specifically symptoms of gastro-oesophageal reflux, overactivity and impulsivity and age, implicate aetiology-specific mechanisms underpinning sleep disturbance. The differences in prevalence, severity and mechanisms implicated in sleep disturbance between groups support a syndrome-sensitive approach to assessment and treatment of sleep disturbance in children with neurodevelopmental disorders.

Electronic supplementary material

The online version of this article (10.1186/s11689-018-9226-0) contains supplementary material, which is available to authorized users.

Association of rare missense variants in the second intracellular loop of NaV1.7 sodium channels with familial autism

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder often accompanied by intellectual disability, language impairment and medical co-morbidities. The heritability of autism is high and multiple genes have been implicated as causal. However, most of these genes have been identified in de novo cases. To further the understanding of familial autism, we performed whole-exome sequencing on five families in which second- and third-degree relatives were affected. By focusing on novel and protein-altering variants, we identified a small set of candidate genes. Among these, a novel private missense C1143F variant in the second intracellular loop of the voltage-gated sodium channel Na_V1.7, encoded by the SCN9A gene, was identified in one family. Through electrophysiological analysis, we show that Na_V1.7^C1143F exhibits partial loss-of-function effects, resulting in slower recovery from inactivation and decreased excitability in cultured cortical neurons. Furthermore, for the same intracellular loop of Na_V1.7, we found an excess of rare variants in a case-control variant-burden study. Functional analysis of one of these variants, M932L/V991L, also demonstrated reduced firing in cortical neurons. However, although this variant is rare in Caucasians, it is frequent in Latino population, suggesting that genetic background can alter its effects on phenotype. Although the involvement of the SCN1A and SCN2A genes encoding Na_V1.1 and Na_V1.2 channels in de novo ASD has previously been demonstrated, our study indicates the involvement of inherited SCN9A variants and partial loss-of-function of Na_V1.7 channels in the etiology of rare familial ASD.

l-Carnosine As an Adjunctive Therapy to Risperidone in Children with Autistic Disorder: A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVES

This study aimed at investigating the efficacy and tolerability of l-carnosine as an add-on to risperidone in the management of children with autism.

METHODS

This was a 10-week, randomized, double-blind, placebo-controlled study. Seventy drug-free children aged 4-12 years old with a diagnosis of autism spectrum disorder (ASD), according to the Diagnostic and Statistical Manual of Mental Disorders, fifth edition. (DSM-5) who had an Aberrant Behavior Checklist-Community (ABC-C) scale irritability subscale score of ≥12, entered the study. The patients were randomly assigned to l-carnosine (800 mg/day in 2 divided doses) or placebo in addition to risperidone titrated up to 2 mg/day (based on body weight) for 10 weeks. The children were assessed by using ABC-C at baseline and weeks 5 and 10 post-baseline. The primary outcome measure was the mean change in the ABC-C irritability subscale score, and other subscale scores were defined as secondary outcomes.

RESULTS

Using the general linear model repeated measures, no significant effect was observed for time × treatment interaction on the irritability subscale scores. However, significant effect was detected on the hyperactivity/noncompliance subscale [F (1.62, 64.96) = 3.53, p-value = 0.044]. No significant improvements were obtained on the lethargy/social withdrawal, stereotypic behavior, and inappropriate speech subscale scores. Significantly greater score reduction in the hyperactivity/noncompliance subscale occurred in the l-carnosine group compared with the placebo group at the end of the trial. Extrapyramidal Symptom Rating Scale Scores and its changes did not differ between the two groups. The frequency of other side effects was not significantly different between the two groups.

CONCLUSIONS

Although no significant difference was detected on the irritability subscale scores, l-carnosine add-on can improve hyperactivity/noncompliance subscales of the ABC-C rating scale in patients with ASD.

Gamma oscillatory activity in vitro: a model system to assess pathophysiological mechanisms of comorbidity between autism and epilepsy

Autism spectrum disorder (ASD) and temporal lobe epilepsy exhibit remarkable comorbidity, but for reasons not clearly understood. To reveal a common pathophysiological mechanism, we here describe and characterize an in vitro epileptiform activity in the rat hippocampus that exhibits common features with in vivo activity in rodent ASD models. We discovered the development of this activity in the CA1 region of horizontal slices after prolonged interictal-like epileptiform activity in the CA3 region that was provoked by incubation in high potassium artificial cerebrospinal fluid. The CA1 epileptiform bursts were insensitive to blockers of glutamatergic transmission, and were carried by synaptic as well as extrasynaptic, tonically activated gamma-aminobutyric acid type A (GABA(A)) receptors. The bursts bear resemblance to in vivo gamma-oscillatory activity found in rat ASD models with respect to their gamma frequency spectrum, their origin (in the CA1), and their sensitivity to blockers of cation-chloride pumps (NKCC1 and KCC2), as well as to oxytocin. Considering this bursting activity as an in vitro model for studying comorbidity between epilepsy and ASD may help to disentangle the intricate interactions that underlie the comorbidity between both diseases and suggests that extrasynaptic tonic GABAergic transmission could represent a potential target for ASD.

Asperger syndrome from childhood into adulthood

Asperger syndrome, a form of autism with normal ability and normal syntactical speech, is associated with a variety of comorbid psychiatric disorders. The disorder is well known to child psychiatry, and we are beginning to recognise the extent of its impact in adulthood. The article reviews the diagnosis and assessment of Asperger syndrome and its links with a wide range of psychiatric issues, including mental disorder, offending and mental capacity. It also describes the broader, non-psychiatric management of Asperger syndrome itself, which includes social and occupational support and education, before touching on the implications the disorder has for our services.