The association between epilepsy and autism symptoms and maladaptive behaviors in children with autism spectrum disorder

Sleep disturbance and other co-occurring conditions in autistic children: A network approach to understanding their inter-relationships

Autistic children frequently have one or more co-occurring psychological, behavioral, or medical conditions. We examined relationships between child behaviors, sleep, adaptive behavior, autistic traits, mental health conditions, and health in autistic children using network analysis. Network analysis is hypothesis generating and can inform our understanding of relationships between multiple conditions and behaviors, directing the development of transdiagnostic treatments for co-occurring conditions. Participants were two child cohorts from the Autism Treatment Network registry: ages 2-5 years (n = 2372) and 6-17 years (n = 1553). Least absolute-shrinkage and selection operator (LASSO) regularized partial correlation network analysis was performed in the 2-5 years cohort (35 items) and the 6-17 years cohort (36 items). The Spinglass algorithm determined communities within each network. Two-step expected influence (EI2) determined the importance of network variables. The most influential network items were sleep difficulties (2 items) and aggressive behaviors for young children and aggressive behaviors, social problems, and anxious/depressed behavior for older children. Five communities were found for younger children and seven for older children. Of the top three most important bridge variables, night-waking/parasomnias and anxious/depressed behavior were in both age-groups, and somatic complaints and sleep initiation/duration were in younger and older cohorts respectively. Despite cohort differences, sleep disturbances were prominent in all networks, indicating they are a transdiagnostic feature across many clinical conditions, and thus a target for intervention and monitoring. Aggressive behavior was influential in the partial correlation networks, indicating a potential red flag for clinical monitoring. Other items of strong network importance may also be intervention targets or screening flags.

Overnight Electroencephalogram to Forecast Epilepsy Development in Children with Autism Spectrum Disorders

OBJECTIVE

To establish the utility of long-term electroencephalogram (EEG) in forecasting epilepsy onset in children with autism spectrum disorder (ASD).

STUDY DESIGN

A single-institution, retrospective analysis of children with ASD, examining long-term overnight EEG recordings collected over a period of 15 years, was conducted. Clinical EEG findings, patient demographics, medical histories, and additional Autism Diagnostic Observation Schedule data were examined. Predictors for the timing of epilepsy onset were evaluated using survival analysis and Cox regression.

RESULTS

Among 151 patients, 17.2% (n = 26) developed unprovoked seizures (Sz group), while 82.8% (n = 125) did not (non-Sz group). The Sz group displayed a higher percentage of interictal epileptiform discharges (IEDs) in their initial EEGs compared with the non-Sz group (46.2% vs 20.0%, P = .01). The Sz group also exhibited a greater frequency of slowing (42.3% vs 13.6%, P < .01). The presence of IEDs or slowing predicted an earlier seizure onset, based on survival analysis. Multivariate Cox proportional hazards regression revealed that the presence of any IEDs (HR 3.83, 95% CI 1.38-10.65, P = .01) or any slowing (HR 2.78, 95% CI 1.02-7.58, P = .046 significantly increased the risk of developing unprovoked seizures.

CONCLUSION

Long-term EEGs are valuable for predicting future epilepsy in children with ASD. These findings can guide clinicians in early education and potential interventions for epilepsy prevention.

Autism and Epilepsy

Epilepsy is one of the most common comorbidities in individuals with autism spectrum disorders (ASDs). Risk factors include the presence of developmental delay/intellectual disability, female sex, age, and an underlying genetic condition. Due to higher prevalence of epilepsy in ASD, it is important to have a high index of suspicion for seizures and refer to a neurologist if there are concerns. Genetic testing is recommended for all children with ASD but it becomes more high yield in children with epilepsy and ASD.

Prevalence of Autism Spectrum Disorder and Co-Morbidities in Children and Adolescents: A Systematic Literature Review

Objective

Individuals with autism spectrum disorder often present somatic and/or psychiatric co-morbid disorders. The DSM-5 allows for consideration of additional diagnoses besides ASD and may have impacted the prevalence of co-morbidities as well as being limited in capturing the true differences in prevalence observed between males and females. We describe the prevalence of ASD and frequently observed co-morbidities in children and adolescents (<18 years) in the United States and five European countries.

Methods

Two systematic literature reviews were conducted in PubMed and Embase for the period 2014-2019 and focusing on the prevalence of ASD and nine co-morbidities of interest based on their frequency and/or severity: Attention Deficit Hyperactivity Disorder (ADHD), anxiety, depressive disorders, epilepsy, intellectual disability (ID), sleep disorders, sight/hearing impairment/loss, and gastro-intestinal syndromes (GI).

Results

Thirteen studies on prevalence of ASD and 33 on prevalence of co-morbidities were included. Prevalence of ASD was 1.70 and 1.85% in U.S children aged 4 and 8 years respectively, while prevalence in Europe ranged between 0.38 and 1.55%. Additionally, current evidence is supportive of a global increase in ASD prevalence over the past years. Substantial heterogeneity in prevalence of co-morbidities was observed: ADHD (0.00-86.00%), anxiety (0.00-82.20%), depressive disorders (0.00-74.80%), epilepsy (2.80-77.50%), ID (0.00-91.70%), sleep disorders (2.08-72.50%), sight/hearing impairment/loss (0.00-14.90%/0.00-4.90%), and GI syndromes (0.00-67.80%). Studies were heterogeneous in terms of design and method to estimate prevalence. Gender appears to represent a risk factor for co-morbid ADHD (higher in males) and epilepsy/seizure (higher in females) while age is also associated with ADHD and anxiety (increasing until adolescence).

Conclusion

Our results provide a descriptive review of the prevalence of ASD and its co-morbidities in children and adolescents. These insights can be valuable for clinicians and parents/guardians of autistic children. Prevalence of ASD has increased over time while co-morbidities bring additional heterogeneity to the clinical presentation, which further advocates for personalized approaches to treatment and support. Having a clear understanding of the prevalence of ASD and its co-morbidities is important to raise awareness among stakeholders.Appeared originally in Front Psychiatry 2021; 12:744709.

Genetic and environmental contributions to co-occurring physical health conditions in autism spectrum condition and attention-deficit/hyperactivity disorder

BACKGROUND

Autism spectrum condition and attention-deficit/hyperactivity disorder (ADHD) are associated with a range of physical health conditions. The aim of this study was to examine the etiological components contributing to co-occurring physical health conditions in autism and ADHD.

METHODS

In this nationwide Child and Adolescent Twin Study in Sweden, we analyzed data from 10,347 twin pairs aged 9 and 12. Clinical diagnoses of autism, ADHD, and physical health conditions were identified through the Swedish National Patient Register. Subclinical phenotypes of autism and ADHD were defined by symptom thresholds on a standardized parent-interview, the Autism-Tics, ADHD, and Other Comorbidities inventory. Associations between physical health conditions and autism/ADHD phenotypes were examined using generalized estimating equations. Bivariate twin models were applied to estimate the extent to which genetic and environmental risk factors accounted for physical health comorbidities.

RESULTS

Similar patterns of association with physical health conditions were found in clinical and subclinical autism/ADHD, with odds ratios ranging from 1.31 for asthma in subclinical ADHD to 8.03 for epilepsy in clinical autism. The estimated genetic correlation (r_a) with epilepsy was 0.50 for clinical autism and 0.35 for subclinical autism. In addition, a modest genetic correlation was estimated between clinical autism and constipation (r_a = 0.31), functional diarrhea (r_a = 0.27) as well as mixed gastrointestinal disorders (r_a = 0.30). Genetic effects contributed 0.86 for mixed gastrointestinal disorders in clinical ADHD (r_a = 0.21). Finally, subclinical ADHD shared genetic risk factors with epilepsy, constipation, and mixed gastrointestinal disorders (r_a = 0.30, 0.17, and 0.17, respectively).

LIMITATIONS

Importantly, since medical records from primary care were not included in the registry data used, we probably identified only more severe rather than the full range of physical health conditions. Furthermore, it needs to be considered that the higher prevalence of physical health conditions among autistic children and children with ADHD could be associated with the increased number of medical visits.

CONCLUSIONS

Shared genetic effects contribute significantly to autism and ADHD phenotypes with the co-occurring physical health conditions across different organ systems, including epilepsy and gastrointestinal disorders. The shared genetic liability with co-occurring physical health conditions was present across different levels of autism and ADHD symptom severity.

Evaluation of Branched-Chain Amino Acids in Children with Autism Spectrum Disorder and Epilepsy

Autism spectrum disorder (ASD) and epilepsy run hand-to-hand in their pathophysiology. Epilepsy is not an uncommon finding in patients with ASD. The aim of the present study was to identify the metabolic abnormalities of BCAAs (leucine, isoleucine, and valine) in children with ASD with and without seizures in comparison with neurotypical controls. Also, this study aimed to investigate the presence of epileptiform discharges on electroencephalography (EEG) in ASD patients and to describe the types and frequency of seizures observed. The study included 90 children aged 2-7 years, 30 of whom were diagnosed with both ASD and epilepsy. The other 30 children were diagnosed as ASD without epilepsy, and a comparable 30 normally developed children served as a control group. The groups were matched by age and gender. All patients were referred to the Autism Disorders Clinic for interviews and examinations. The Childhood Autism Rating Scale (CARS) was applied to all study participants to assess the degree of autism. The present study results show that all types of seizures may be identified in ASD children. The median serum levels of BCAAs were lower in ASD children with and without epilepsy than in neurotypical controls. This opens the door for discussion about new etiologies and better categorizations of ASD based on genotype and genetic abnormalities detected. More studies with larger samples are needed to understand ASD better and to more reliable evaluate the association between ASD, EEG changes, seizures, and BCAAs.

Epilepsy and EEG Abnormalities in Children with Autism Spectrum Disorders

OBJECTIVE

To evaluate the prevalence of epilepsy and  electroencephalographic abnormalities in children with autism spectrum disorders (ASD) and determine their risk factors.

METHODS

This cross-sectional study was conducted over one year in children with ASD aged between 3 and 14 y. Classification of epilepsy and routine electroencephalography (EEG) recordings were done for all the patients. Developmental and cognitive assessments were done using Developmental Profile 3. Children were divided into three groups: ASD with epilepsy, ASD with isolated electroencephalographic abnormalities, and ASD with neither epilepsy nor electroencephalographic abnormalities.

RESULTS

One hundred children with ASD were enrolled. Epilepsy was reported in 23% and subclinical electroencephalographic abnormalities were documented in 8%. The most common seizure types were generalized-onset tonic-clonic (48%), focal-onset with impaired awareness (17%), and focal to bilateral tonic-clonic seizures (17%). In children with subclinical epileptiform discharges, focal abnormalities were most common (75%) and were maximally seen over the temporal region (50%). Subnormal intellect (88.6%) and abnormal global developmental score (82%) were noted in the majority of children. Female gender, abnormal neurological examination, and adverse perinatal events were significantly associated with epilepsy. Of these, female gender and adverse perinatal events were independent predictors of epilepsy. Isolated EEG abnormalities were significantly associated with abnormal neurological examination in comparison with autistic children without epilepsy/EEG abnormalities.

CONCLUSION

Epilepsy is seen in up to one-fourth children with ASD. Female gender and adverse perinatal events are independent risk factors for epilepsy. Subclinical or isolated EEG abnormalities are associated with abnormal neurological examination.

Modeling dopamine dysfunction in autism spectrum disorder: From invertebrates to vertebrates

Autism Spectrum Disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by deficits in social communication and by patterns of restricted interests and/or repetitive behaviors. The Simons Foundation Autism Research Initiative's Human Gene and CNV Modules now list over 1000 genes implicated in ASD and over 2000 copy number variant loci reported in individuals with ASD. Given this ever-growing list of genetic changes associated with ASD, it has become evident that there is likely not a single genetic cause of this disorder nor a single neurobiological basis of this disorder. Instead, it is likely that many different neurobiological perturbations (which may represent subtypes of ASD) can result in the set of behavioral symptoms that we called ASD. One such of possible subtype of ASD may be associated with dopamine dysfunction. Precise regulation of synaptic dopamine (DA) is required for reward processing and behavioral learning, behaviors which are disrupted in ASD. Here we review evidence for DA dysfunction in ASD and in animal models of ASD. Further, we propose that these studies provide a scaffold for scientists and clinicians to consider subcategorizing the ASD diagnosis based on the genetic changes, neurobiological difference, and behavioral features identified in individuals with ASD.

Evaluating the DeepSqueak and Mouse Song Analyzer vocalization analysis systems in C57BL/6J, FVB.129, and FVB neonates

BACKGROUND

Communication is an essential behavior in mammals. Alterations in communication (neonatal crying) characterize numerous human neurodevelopmental conditions. Mice produce communicative vocalizations, known as ultrasonic vocalizations, (USVs) that can be recorded. The Mouse Song Analyzer is an automated USV analysis system while DeepSqueak is a semi-automated USV detection system.

METHOD

We used data from, C57BL/6J, FVB.129, and FVB neonates to compare the reliability of DeepSqueak and the Mouse Song Analyzer across various acoustic variables.

RESULTS

We found that both systems detected a similar quantity of USVs for FVB.129 and FVB mice. However, DeepSqueak detected more USVs for C57BL/6J mice. High correlations were found between systems for each strain. When assessing duration, Deepsqueak detected USVs of a longer duration then the Mouse Song Analyzer across all strains. A low correlation between systems for duration was found for FVB.129 mice, while high correlations were found for C57BL/6J and FVB mice. When assessing fundamental frequency, the Mouse Song Analyzer detected a higher frequency than DeepSqueak for FVB.129 mice, with no other differences present. High correlations between systems were found for C57BL/6J and FVB.129 mice, while a low correlation was found for FVB mice. We also assessed each system's sensitivity and found that Deepsqueak was able to detect softer USVs than the Mouse Song Analyzer.

CONCLUSIONS

These findings demonstrate that the strain of mouse used significantly affects the reliability of USV analysis systems. However, our data also indicates that DeepSqueak is more reliable and accurate than the Mouse Song Analyzer due to its increased sensitivity.

Neurodevelopmental Outcomes of High-Risk Preterm Infants: A Prospective Study in Japan

Objectives

To determine the neurodevelopmental outcomes of very-low-birth-weight infants (VLBWIs, birth weight <1,500 g) after 9 years of follow-up.

Methods

This study prospectively recruited 224 VLBWIs born from 2003 to 2009 in Kyushu University Hospital, Japan. Comorbidities of neurocognitive impairment, epilepsy, and autism spectrum disorder or attention-deficit hyperactivity disorder (ASD/ADHD) were assessed at age 3, 6, and 9 years.

Results

Neurodevelopmental profiles were obtained from 185 (83%), 150 (67%), and 119 (53%) participants at age 3, 6, and 9 years, respectively. At age 9 years, 25 (21%) VLBWIs showed intelligence quotient (IQ) <70, 11 (9%) developed epilepsy, and 14 (12%) had a diagnosis of ASD/ADHD. The prevalence of epilepsy was higher in children with an IQ <70 at age 9 years than in those with an IQ ≥70 (44% vs 0%). In contrast, ASD/ADHD appeared at similar frequencies in children with an IQ <70 (16%) and ≥70 (11%). Perinatal complications and severe brain lesions on MRI were considered common perinatal risks for developmental delay and epilepsy but not for ASD/ADHD. Male sex was identified as a unique risk factor for ASD/ADHD.

Conclusion

These data suggest that VLBWIs showed a higher prevalence of developmental delay, epilepsy, and ASD/ADHD at age 9 years than the general population. Distinct mechanisms might be involved in the pathogenic process of ASD/ADHD from those of developmental delay and epilepsy.

Autism comorbidities show elevated female-to-male odds ratios and are associated with the age of first autism diagnosis

OBJECTIVE

To investigate the association between the comorbidity rates in autism and sex, birth year and the age at which autism was first diagnosed and compare the relative impact of each.

METHOD

Using the Danish National Patient Registry, cumulative incidences up to the age of 16 for 11 comorbid conditions (psychosis, affective disorders, anxiety disorders, conduct disorder, eating disorders, obsessive-compulsive disorder, attention-deficit hyperactivity disorder, epilepsy, tic disorders, sleep disorders or intellectual disability) were calculated for individuals with autism (N = 16,126) and non-autism individuals (N = 654,977). Individuals were further stratified based on the age at the first autism diagnoses and comorbid diagnoses up to the age of 16 were compared.

RESULTS

Most comorbidities were significantly associated with birth year and sex. Female/male odds ratios for 8 of 11 comorbid conditions were up to 67% higher than the corresponding odds ratios in the non-autism population, including conditions that are generally more common in males than in females as well as conditions that are more common in females. All comorbidity rates were significantly associated with the age at the first autism diagnosis, which was a stronger predictor than sex and birth year for 8 conditions.

CONCLUSIONS

Comorbidity rates for females exceed what would be expected based on the sex ratios among non-autistic individuals, indicating that the association between autism and comorbidity is stronger in females. Comorbidity rates are also highly dependent on the age at the first autism diagnosis, which may contribute to autism heterogeneity in research and clinical practice.

Social impairment in children with epilepsy assessed by the social responsiveness scale

Children with epilepsy are at risk for impaired social cognition and autism. We aimed at evaluating the utility of the social responsiveness scale (SRS) for assessment of social impairment in these children. Prospective study; the SRS was applied to a group of children with epilepsy and a healthy control group. Intellectual disability in the epilepsy group was assessed utilizing adapted versions of the Wechsler Intelligence and adaptive behavior scales. One hundred and one children with epilepsy and 92 healthy children were included. The majority of children in both groups had normal SRS scores. Significant differences were identified in children with high total scores indicating significant deficiencies in reciprocal social behavior; high scores were found in 16% of children with epilepsy versus 7% of normal children, p < .05, particularly involving social communication, p < .05. Intellectual disability was identified in 42% of children with epilepsy, particularly processing speed index, p < .001. Intellectual disability had a significant effect on total scores, p = .016. Children with epilepsy have increased risk of social impairments. Social impairments are more likely in the presence of intellectual disability. The SRS is a quick identification tool that can be employed in the outpatient setting.

Prevalence of epilepsy in autism spectrum disorders: A systematic review and meta-analysis

LAY ABSTRACT

Autistic individuals experience higher co-occurring medical conditions than the general population, and yet the estimates of autistic individuals with epilepsy are not updated. Co-occurrence of epilepsy in autistic individuals often aggravated cognitive impairment and increased the risk of poor long-term prognosis. Thus, an updated systematic review and meta-analysis was conducted to study the relevant articles published from inception to 2020, evaluate the prevalence of epilepsy in autistic individuals, and further explore the putative factors influencing the prevalence. A total of 66 studies from 53 articles were included in this study. The results showed that epilepsy is more common in autistic individuals than in the general population. The prevalence of epilepsy in autistic individuals in the clinical sample-based studies was higher than that in the population-based based cross-sectional or cohort studies. The prevalence of epilepsy in autistic adults was higher than that in autistic children. A significantly increased prevalence of epilepsy was detected in the autistic adolescent group (11-17 years old), and a higher trend of prevalence of epilepsy was observed in the autistic pre-school group (⩽ 6 -years-old) than that of the autistic school-aged group (7-10 years-old). The prevalence of epilepsy increased with age, female rate, and low intellectual function rate of autistic individuals. However, the human development index of countries was negatively associated with the pooled prevalence, which could be attributed to the different levels of awareness, diagnostic technologies, and autism-service support worldwide. About 1/10 autistic individuals also had epilepsy, which was common in the clinical setting, adolescents, adults, females, or patients with intellectual disability and less common in the country with high human development index. Thus, these findings provided critical and innovative views on the prevalence of epilepsy in autistic individuals and contributed to the targeted clinical management and preventive measures.

The prevalence and profile of autism in Sturge-Weber syndrome

A systematic retrospective case note review was undertaken to investigate autism diagnostic factors in 124 individuals with Sturge-Weber syndrome (SWS). Social Responsiveness Scale questionnaires were then analysed to explore the severity and profile of autism characteristics in 70 participants. Thirty-two to forty percent of participants had a clinical diagnosis of autism and half of those without a diagnosis showed significant social communication difficulties. Children had a relative strength in social awareness and social motivation, which are typically much reduced in people with autism. This finding may explain why, to date, the diagnosis has often been overlooked in this population. The research therefore suggests that children with Sturge-Weber should be screened to identify social communications difficulties and provided with timely support.

Seizures and Epilepsy in Autism Spectrum Disorder

Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.

CD-1 Outbred Mice Produce Less Variable Ultrasonic Vocalizations Than FVB Inbred Mice, While Displaying a Similar Developmental Trajectory

The production of ultrasonic vocalizations (USVs) in neonatal mice is a critical means of communication that is used to elicit maternal care. Alterations in neonatal USV production is also an indicator of neurological deficits. However, USVs have been predominately assessed in inbred animals and are significantly understudied in outbred mice, even though outbred animals better represent the genetic diversity of humans and are used in several neurological disorder models. To determine the reproducibility of USVs across models, we compared male and female CD-1 (outbred) and FVB (inbred) mice on postnatal days (PD) 4, 8, 12, 16, and 20. We found that CD-1 and FVB mice displayed a similar developmental trajectory of USVs. However, CD1 mice emitted more USVs on PD 12 than FVB mice. In addition, FVB mice emitted a longer duration of calls on PD 4 and 8 and a higher overall maximum and minimum frequency of USVs than CD-1 mice. No differences in mean amplitude were found between groups. We also detected numerous significant differences between outbred and inbred mice when comparing each group's call composition. We next assessed the relative variability of mouse vocalizations between groups, finding that outbred mice were less variable than inbred mice. For the spectral and temporal characteristics of the USVs, variability was similar between groups. Altogether, we found that CD-1 outbred mice display a similar, if not lower, degree of variability than FVB inbred mice when assessing neonatal USVs.

Investigating the Role of Inattention and/or Hyperactivity/impulsivity in Language and Social Functioning Using a Dimensional Approach

The current study parsed out the distinct components of attention-deficit/hyperactivity disorder (ADHD) symptomatology to examine differential relations with language and social ability. Using a research domain criteria (RDoC) framework, we administered standardized tests and previously developed and validated questionnaires to assess levels of inattention and/or hyperactivity/impulsivity symptomatology, language, social responsivity and social competency in 98 young adults. Those with higher inattention and/or hyperactivity/impulsivity symptomatology had reduced language comprehension, social responsivity, and social competency. Inattention and hyperactivity/impulsivity both predicted language comprehension, but not language production. Interestingly, inattention uniquely contributed to social responsiveness and social competency, but hyperactivity/impulsivity did not. Findings suggest that inattention and/or hyperactivity/impulsivity symptoms, inattention in particular, may be especially important for social skills programs geared towards individuals with attention limitations.

Prevalence of Autism Spectrum Disorder and Co-morbidities in Children and Adolescents: A Systematic Literature Review

Objective: Individuals with autism spectrum disorder often present somatic and/or psychiatric co-morbid disorders. The DSM-5 allows for consideration of additional diagnoses besides ASD and may have impacted the prevalence of co-morbidities as well as being limited in capturing the true differences in prevalence observed between males and females. We describe the prevalence of ASD and frequently observed co-morbidities in children and adolescents (<18 years) in the United States and five European countries. Methods: Two systematic literature reviews were conducted in PubMed and Embase for the period 2014-2019 and focusing on the prevalence of ASD and nine co-morbidities of interest based on their frequency and/or severity: Attention Deficit Hyperactivity Disorder (ADHD), anxiety, depressive disorders, epilepsy, intellectual disability (ID), sleep disorders, sight/hearing impairment/loss, and gastro-intestinal syndromes (GI). Results: Thirteen studies on prevalence of ASD and 33 on prevalence of co-morbidities were included. Prevalence of ASD was 1.70 and 1.85% in US children aged 4 and 8 years respectively, while prevalence in Europe ranged between 0.38 and 1.55%. Additionally, current evidence is supportive of a global increase in ASD prevalence over the past years. Substantial heterogeneity in prevalence of co-morbidities was observed: ADHD (0.00-86.00%), anxiety (0.00-82.20%), depressive disorders (0.00-74.80%), epilepsy (2.80-77.50%), ID (0.00-91.70%), sleep disorders (2.08-72.50%), sight/hearing impairment/loss (0.00-14.90%/0.00-4.90%), and GI syndromes (0.00-67.80%). Studies were heterogeneous in terms of design and method to estimate prevalence. Gender appears to represent a risk factor for co-morbid ADHD (higher in males) and epilepsy/seizure (higher in females) while age is also associated with ADHD and anxiety (increasing until adolescence). Conclusion: Our results provide a descriptive review of the prevalence of ASD and its co-morbidities in children and adolescents. These insights can be valuable for clinicians and parents/guardians of autistic children. Prevalence of ASD has increased over time while co-morbidities bring additional heterogeneity to the clinical presentation, which further advocates for personalized approaches to treatment and support. Having a clear understanding of the prevalence of ASD and its co-morbidities is important to raise awareness among stakeholders.

A Unifying Theory for Autism: The Pathogenetic Triad as a Theoretical Framework

This paper presents a unifying theory for autism by applying the framework of a pathogenetic triad to the scientific literature. It proposes a deconstruction of autism into three contributing features (an autistic personality dimension, cognitive compensation, and neuropathological risk factors), and delineates how they interact to cause a maladaptive behavioral phenotype that may require a clinical diagnosis. The autistic personality represents a common core condition, which induces a set of behavioral issues when pronounced. These issues are compensated for by cognitive mechanisms, allowing the individual to remain adaptive and functional. Risk factors, both exogenous and endogenous ones, show pathophysiological convergence through their negative effects on neurodevelopment. This secondarily affects cognitive compensation, which disinhibits a maladaptive behavioral phenotype. The triad is operationalized and methods for quantification are presented. With respect to the breadth of findings in the literature that it can incorporate, it is the most comprehensive model yet for autism. Its main implications are that (1) it presents the broader autism phenotype as a non-pathological core personality domain, which is shared across the population and uncoupled from associated features such as low cognitive ability and immune dysfunction, (2) it proposes that common genetic variants underly the personality domain, and that rare variants act as risk factors through negative effects on neurodevelopment, (3) it outlines a common pathophysiological mechanism, through inhibition of neurodevelopment and cognitive dysfunction, by which a wide range of endogenous and exogenous risk factors lead to autism, and (4) it suggests that contributing risk factors, and findings of immune and autonomic dysfunction are clinically ascertained rather than part of the core autism construct.

A comparison of the Avisoft (v.5.2) and MATLAB Mouse Song Analyzer (v.1.3) vocalization analysis systems in C57BL/6, Fmr1-FVB.129, NS-Pten-FVB, and 129 mice

BACKGROUND

Communicative behaviors play a vital role in mammals and are highly relevant to human neurodevelopmental conditions. Mice produce communicative vocalizations that occur in the ultrasonic range, which are commonly analyzed within the Avisoft recording system. Fully automated programs such as the Mouse Song Analyzer in MATLAB, have been developed to analyze USVs in a shorter time period, however, no study has compared the accuracy of MATLAB to Avisoft.

NEW METHOD

In order to determine MATLAB's accuracy, we used data from four different mouse strains and assessed whether the total number of USVs detected was similar between systems.

RESULTS

We found that there was a high correlation between systems for the number of USVs emitted from C57BL/6 and NS-Pten mice however, Avisoft detected significantly more USVs than MATLAB for both strains. For Fmr1-FVB.129 and 129 mice, large correlations were observed between systems and no significant difference was present in the USVs detected. A partial correlation was run to control for the covariates: sex, age, strain, and treatment, and found that only strain substantially influences the relationship between the USVs detected in Avisoft and those detected in MATLAB.

COMPARISON WITH EXISTING METHOD

These findings demonstrate that there is a high degree of agreement between Avisoft and the Mouse Song Analyzer however, Avisoft does detect significantly more USVs depending on the strain assessed.

CONCLUSIONS

Therefore, there are relative advantages and disadvantages with both systems that vocalization researchers should be aware of when interpreting USV results, and when using either system.

Neurological disorders in autism: A systematic review and meta-analysis

LAY ABSTRACT

Neurological disorders, such as epilepsy and cerebral palsy, have been reported to occur among individuals with autism beyond chance and may have an impact on daily living across the lifespan. Although there has been research investigating neurological disorders in autism, the findings are not always conclusive. Previous summaries of existing studies have not evaluated the full range of neurological disorders. This study aimed to comprehensively explore the neurological problems appearing in autism to provide updated information that is needed for better healthcare and support in this population. We looked at already published studies focusing on risk or frequency of neurological disorders in autism. Our results suggest that individuals with autism are more likely than the general population to have a range of neurological disorders, including epilepsy, macrocephaly, hydrocephalus, cerebral palsy, migraine/headache, and inborn abnormalities of the nervous system. In order to provide individualized healthcare and support of high quality to individuals diagnosed with autism, health care professionals and other support providers need to be attentive to neurological complications. To further improve our understanding about the link between autism and neurological disorders, future research should follow the neurological health of children who are diagnosed with or are at increased likelihood of autism.

Prenatal pregabalin is associated with sex-dependent alterations in some behavioral parameters in valproic acid-induced autism in rat offspring

This study was performed to evaluate the effects of prenatal exposure to pregabalin (PGB) on behavioral changes of rat offspring in an animal model of valproic acid (VPA)-induced autism-like symptoms. Pregnant rats received VPA (600 mg/kg/i.p.) once at 12.5 gestational days for autism-like symptom induction in offspring. After the delivery single male and single female offspring from each mother were randomly selected for behavioral test (anxiety, pain response, pleasure, and motor function) at 60th day adulthood (n = 7). Offspring received prenatal PGB (15 & 30 mg/kg/i.p.) during gestational days 9.5 to 15.5 either alone or in combination with VPA (PGB15, PGB30, PGB15 + VPA, and PGB30 + VPA). Control offspring received normal saline during the same period. The result showed that prenatal VPA exposure was associated with autism-like behaviors in rat offspring. PGB treatment during the gestational period revealed significant reduction in sucrose preference test and anxiety in elevated plus maze and open field test in offspring. Also, PGB treatments exhibited a dose-dependent increase in pain threshold in prenatally VPA exposed rats in tail-flick and hot plate test. Also, there was a sex-related significant impairment in motor function in beam balance and open field test, and male rats were affected more than females. However, no significant sex differences in sucrose preference and pain sensitivity were observed in prenatal PGB-treated rat offspring. In conclusion, prenatal exposure to VPA increased the risk of autism-like behaviors in the offspring rats, and PGB treatment during the gestational period was associated with some beneficial effects, including anxiety reduction and motor impairment in autism-like symptoms in rat offspring.

Seizures and Epilepsy in Autism Spectrum Disorder

Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.

Factors Associated With Seizure Onset in Children With Autism Spectrum Disorder

BACKGROUND AND OBJECTIVES

Children with autism spectrum disorder (ASD) have a higher prevalence of epilepsy compared with general populations. In this pilot study, we prospectively identified baseline risk factors for the development of seizures in individuals with ASD and also identified characteristics sensitive to seizure onset up to 6 years after enrollment in the Autism Speaks Autism Treatment Network.

METHODS

Children with ASD and no history of seizures at baseline who either experienced onset of seizures after enrollment in the Autism Treatment Network or remained seizure free were included in the analysis.

RESULTS

Among 472 qualifying children, 22 (4.7%) experienced onset of seizures after enrollment. Individuals who developed seizures after enrollment exhibited lower scores at baseline on all domains of the Vineland Adaptive Behavior Scales, greater hyperactivity on the Aberrant Behavior Checklist (25.4 ± 11.8 vs 19.2 ± 11.1; P = .018), and lower physical quality of life scores on the Pediatric Quality of Life Inventory (60.1 ± 24.2 vs 76.0 ± 18.2; P < .001). Comparing change in scores from entry to call-back, adjusting for age, sex, length of follow-up, and baseline Vineland II composite score, individuals who developed seizures experienced declines in daily living skills (-8.38; 95% confidence interval -14.50 to -2.50; P = .005). Adjusting for baseline age, sex, and length of follow-up, baseline Vineland II composite score was predictive of seizure development (risk ratio = 0.95 per unit Vineland II composite score, 95% confidence interval 0.92 to 0.99; P = .007).

CONCLUSIONS

Individuals with ASD at risk for seizures exhibited changes in adaptive functioning and behavior.

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.

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.

Retrieval-Induced Forgetting in a Pentylenetetrazole-Induced Epilepsy Model in the Rat

The selective retrieval of some information may lead to the forgetting of related, but non-retrieved information. This memory phenomenon is termed retrieval-induced forgetting (RIF). Active inhibition is thought to function to resolve interference from competing information during retrieval, which results in forgetting. Epilepsy is associated with impaired inhibitory control that contributes to executive dysfunction. The purpose of this study is to investigate whether rats in a kindling model of epilepsy demonstrate normal levels of RIF. Rats were divided into two groups: saline and kindling. Pentylenetetrazole was injected intraperitoneally until the rats kindled. RIF was tested using a modified version of the spontaneous object recognition test, consisting of a sample phase, retrieval or interference phase, and a test phase. Exploration time for each object was analyzed. RIF was demonstrated in the saline group when rats subjected to the retrieval phase failed to discriminate between the familiar object and the novel object later in the test phase. Kindled rats, on the other hand, did not suffer forgetting even when they were subjected to the retrieval phase, as they spent significantly longer times exploring the novel rather than the familiar object in the test phase. Therefore, RIF was not observed in the kindling group. These findings indicate impaired retrieval-induced forgetting in kindled rats, which may be suggestive of a deficit in the inhibitory control of memory.

Relation of Psychiatric Symptoms with Epilepsy, Asthma, and Allergy in Youth with ASD vs. Psychiatry Referrals

The present study aimed to characterize the association of psychopathology with the clinical correlates of epilepsy, asthma, and allergy within and between neurobehavioral syndromes. Participants were consecutively evaluated youth (6-18 years, 75 % male) with autism spectrum disorder (ASD; n = 589) and non-ASD outpatient psychiatry referrals (n = 653). Informants completed a background questionnaire (parents) and a psychiatric symptom severity rating scale (parents, teachers). Youth with ASD had higher rates of epilepsy and allergy but not asthma than psychiatry referrals, even when analyses were limited to youth with IQ ≥ 70. Somatic conditions evidenced variable associations with medical services utilization, educational interventions, family income, and maternal education. Youth with ASD with versus without epilepsy had more severe ASD social deficits (parents' ratings) and less severe ASD repetitive behaviors (teachers' ratings). Epilepsy was associated with more severe depression, mania, and schizophrenia symptoms in youth with ASD. Youth with allergy (psychiatry referrals only) had more severe anxiety and depression symptoms (parents' ratings) but less severe aggression (teachers' ratings) thus providing evidence of both context- and diagnostic-specificity. Youth with ASD versus non-ASD psychiatry referrals evidence a variable pattern of relations between somatic conditions and a range of clinical correlates, which suggests that the biologic substrates and psychosocial concomitants of neurodevelopmental disorders and their co-occurring somatic conditions may interact to produce unique clinical phenotypes.

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.

Characterizing the Interplay Between Autism Spectrum Disorder and Comorbid Medical Conditions: An Integrative Review

Co-occurring medical disorders and associated physiological abnormalities in individuals with autism spectrum disorder (ASD) may provide insight into causal pathways or underlying biological mechanisms. Here, we review medical conditions that have been repeatedly highlighted as sharing the strongest associations with ASD-epilepsy, sleep, as well as gastrointestinal and immune functioning. We describe within each condition their prevalence, associations with behavior, and evidence for successful treatment. We additionally discuss research aiming to uncover potential aetiological mechanisms. We then consider the potential interaction between each group of conditions and ASD and, based on the available evidence, propose a model that integrates these medical comorbidities in relation to potential shared aetiological mechanisms. Future research should aim to systematically examine the interactions between these physiological systems, rather than considering these in isolation, using robust and sensitive biomarkers across an individual's development. A consideration of the overlap between medical conditions and ASD may aid in defining biological subtypes within ASD and in the development of specific targeted interventions.

Association of Rigid-Compulsive Behavior with Functional Constipation in Autism Spectrum Disorder

Based upon checklist data from the Autism Speaks Autism Treatment Network, we hypothesized that functional constipation (FC) would be associated with rigid-compulsive behavior in children with autism spectrum disorder (ASD). We used the Questionnaire on Pediatric Gastrointestinal Symptoms-Rome III to assess FC symptoms in 108 children with ASD. As hypothesized, FC was associated with parent ratings on the Repetitive Behavior Scales-Revised (RBS-R) Compulsive, Ritualistic, and Sameness subscales in the overall population. Of note, FC was less common in children who were not taking medications that target behavior or treat FC. In the medication-free children, rigid-compulsive behavior was not significantly associated with FC. More research is needed to understand the mechanisms underlying these associations.

SSa ameliorates the Glu uptaking capacity of astrocytes in epilepsy via AP-1/miR-155/GLAST

BACKGROUND

Neuronal glutamate (Glu) release has been reported to mediate the neuronal injury of epilepsy, while Saikosaponin a (Ssa) was shown to ameliorate the epilepsy that induced by pentylenetetrazol (PTZ). However, potential interactions between glutamate release and Ssa has not been fully identified.

METHODS

Herein, PTZ-induced rat model were established to evaluate the neuron injury, while Ssa was used to treat the model rat. Rat astrocytes were isolated and induced by PTZ to construct cell models of epilepsy, real-time PCR and western blot were used to determine genes' expression. Luciferase reporter assay were performed to validate the relationship between miR-155-5p and glutamate aspartate transporter (GLAST). The level of Glu was sampled for HPLC measurement.

RESULTS

Ssa treatment could decrease the level of Glu in hippocampus of rat. PTZ-induced astrocytes pretreated with Ssa significantly decreased the expression of AP-1 and miR-155, but increased the expression of GLAST, furthermore, PTZ stimulation enables astrocytes to uptake large amount of extracellular Glu. AP-1 could bind with the promoter of miR-155 to promote its transcription. MiR-155 tragets GLAST to govern its expression.

CONCLUSION

Ssa treatment played pivotal roles in PTZ-induced epilepsy by promoting the expression of GLAT1 and uptaking of Glu, which was mediated by the expression of AP-1 and miR-155.

Factors Associated with Self-Injurious Behaviors in Children with Autism Spectrum Disorder: Findings from Two Large National Samples

In this study, we explored potential associations among self-injurious behaviors (SIB) and a diverse group of protective and risk factors in children with autism spectrum disorder from two databases: Autism and Developmental Disabilities Monitoring (ADDM) Network and the Autism Speaks-Autism Treatment Network (AS-ATN). The presence of SIB was determined from children's records in ADDM and a parent questionnaire in AS-ATN. We used multiple imputation to account for missing data and a non-linear mixed model with site as a random effect to test for associations. Despite differences between the two databases, similar associations were found; SIB were associated with developmental, behavioral, and somatic factors. Implications of these findings are discussed in relation to possible etiology, future longitudinal studies, and clinical practice.

SLC9A9 Co-expression modules in autism-associated brain regions

SLC9A9 is a sodium hydrogen exchanger present in the recycling endosome and highly expressed in the brain. It is implicated in neuropsychiatric disorders, including autism spectrum disorders (ASDs). Little research concerning its gene expression patterns and biological pathways has been conducted. We sought to investigate its possible biological roles in autism-associated brain regions throughout development. We conducted a weighted gene co-expression network analysis on RNA-seq data downloaded from Brainspan. We compared prenatal and postnatal gene expression networks for three ASD-associated brain regions known to have high SLC9A9 gene expression. We also performed an ASD-associated single nucleotide polymorphism enrichment analysis and a cell signature enrichment analysis. The modules showed differences in gene constituents (membership), gene number, and connectivity throughout time. SLC9A9 was highly associated with immune system functions, metabolism, apoptosis, endocytosis, and signaling cascades. Gene list comparison with co-immunoprecipitation data was significant for multiple modules. We found a disproportionately high autism risk signal among genes constituting the prenatal hippocampal module. The modules were enriched with astrocyte and oligodendrocyte markers. SLC9A9 is potentially involved in the pathophysiology of ASDs. Our investigation confirmed proposed functions for SLC9A9, such as endocytosis and immune regulation, while also revealing potential roles in mTOR signaling and cell survival.. By providing a concise molecular map and interactions, evidence of cell type and implicated brain regions we hope this will guide future research on SLC9A9. Autism Res 2017, 10: 414-429. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

The effect of epilepsy on autistic symptom severity assessed by the social responsiveness scale in children with autism spectrum disorder

BACKGROUND

As the prevalence of autism spectrum disorders in people with epilepsy ranges from 15 to 47 % (Clarke et al. in Epilepsia 46:1970-1977, 2005), it is speculated that there is a special relationship between the two disorders, yet there has been a lack of systematic studies comparing the behavioral phenotype between autistic individuals and autistic individuals with epilepsy. This study aims to investigate how the co-occurrence of epilepsy and Autism Spectrum Disorder (ASD) affects autistic characteristics assessed by the Social Responsiveness Scale (SRS), which has been used as a measure of autism symptoms in previous studies. In this research we referred to all individuals with Autism or Autistic Disorder as individuals with ASD.

METHODS

We reviewed the complete medical records of 182 participants who presented to a single tertiary care referral center from January 1, 2013 to July 28, 2015, and subsequently received complete child and adolescent psychiatric assessments. Of the 182 participants, 22 were diagnosed with Autism Spectrum Disorder and epilepsy. Types of epilepsy observed in these individuals included complex partial seizure, generalized tonic-clonic seizure, or infantile spasm. Using 'Propensity Score Matching' we selected 44 children, diagnosed with only Autism Spectrum Disorder, whose age, gender, and intelligence quotient (IQ) were closely matched with the 22 children diagnosed with Autism Spectrum Disorder and epilepsy. Social functioning of participants was assessed by the social responsiveness scale, which consists of five categories: social awareness, social cognition, social communication, social motivation, and autistic mannerisms. Bivariate analyses were conducted to compare the ASD participants with epilepsy group with the ASD-only group on demographic and clinical characteristics. Chi square and t test p values were calculated when appropriate.

RESULTS

There was no significant difference in age (p = 0.172), gender (p > 0.999), IQ (FSIQ, p = 0.139; VIQ, p = 0.114; PIQ, p = 0.295) between the two groups. ASD participants with epilepsy were significantly more impaired than ASD participants on some measures of social functioning such as social awareness (p = 0.03) and social communication (p = 0.027). ASD participants with epilepsy also scored significantly higher on total SRS t-score than ASD participants (p = 0.023).

CONCLUSIONS

Understanding the relationship between ASD and epilepsy is critical for appropriate management (e.g. social skills training, seizure control) of ASD participants with co-occurring epilepsy. Results of this study suggest that mechanisms involved in producing epilepsy may play a role in producing or augmenting autistic features such as poor social functioning. Prospective study with larger sample sizes is warranted to further explore this association.

Clinical characteristics of children and young adults with co-occurring autism spectrum disorder and epilepsy

The association between autism spectrum disorder (ASD) and epilepsy has been described for decades, and yet we still lack the full understanding of this relationship both clinically and at the pathophysiologic level. This review evaluates the available data in the literature pertaining to the clinical characteristics of patients with autism spectrum disorder who develop epilepsy and, conversely, patients with epilepsy who develop autism spectrum disorder. Many studies demonstrate an increased risk of epilepsy in individuals with ASD, but rates vary widely. This variability is likely secondary to the different study methods employed, including the study population and definitions of the disorders. Established risk factors for an increased risk of epilepsy in patients with ASD include intellectual disability and female gender. There is some evidence of an increased risk of epilepsy associated with other factors such as ASD etiology (syndromic), severity of autistic features, developmental regression, and family history. No one epilepsy syndrome or seizure type has been associated, although focal or localization-related seizures are often reported. The age at seizure onset can vary from infancy to adulthood with some evidence of a bimodal age distribution. The severity and intractability of epilepsy in populations with ASD have not been well studied, and there is very little investigation of the role that epilepsy plays in the autism behavioral phenotype. There is evidence of abnormal EEGs (especially epileptiform abnormalities) in children with ASD even in the absence of clinical seizures, but very little is known about this phenomenon and what it means. The development of autism spectrum disorder in patients with epilepsy is less well studied, but there is evidence that the ASD risk is greater in those with epilepsy than in the general population. One of the risk factors is intellectual disability, and there is some evidence that the presence of a particular seizure type, infantile spasms, may increase risk, but some of the data are conflicting. We believe that one of the reasons that so little is known about this phenomenon is the lack of cross talk between researchers and clinicians alike in the two fields. We conclude that large systematic studies that employ strict ascertainment of samples using standardized definitions of both disorders, validated data collection tools, and appropriate longitudinal follow-up are needed to better shed light on certain clinical aspects of the comorbidity of ASD and epilepsy. Ideally, we could provide the optimal diagnostic and treatment services to these patients in a multidisciplinary setting with both epilepsy and neurobehavioral specialists. This article is part of a Special Issue entitled "Autism and Epilepsy".

Optimizing neuronal differentiation from induced pluripotent stem cells to model ASD

Autism spectrum disorder (ASD) is an early-onset neurodevelopmental disorder characterized by deficits in social communication, and restricted and repetitive patterns of behavior. Despite its high prevalence, discovery of pathophysiological mechanisms underlying ASD has lagged due to a lack of appropriate model systems. Recent advances in induced pluripotent stem cell (iPSC) technology and neural differentiation techniques allow for detailed functional analyses of neurons generated from living individuals with ASD. Refinement of cortical neuron differentiation methods from iPSCs will enable mechanistic studies of specific neuronal subpopulations that may be preferentially impaired in ASD. In this review, we summarize recent accomplishments in differentiation of cortical neurons from human pluripotent stems cells and efforts to establish in vitro model systems to study ASD using personalized neurons.