Prevalence and onset of regression within autism spectrum disorders: a meta-analytic review

Bidirectional association between autism spectrum disorder and epilepsy in child and adolescent patients: a population-based cohort study

This study aimed to assess whether there is a bidirectional association between autism spectrum disorder (ASD) and epilepsy in child and adolescent patients. The National Health Insurance Research Database of Taiwan was used to conduct two cohort studies of patients who were under 18 years of age during the period 1997-2008. Cohort 1 comprised patients with newly diagnosed ASD but excluded those diagnosed with epilepsy prior to ASD. A non-ASD comparison group was matched to each case in terms of age and sex. Cohort 2 comprised patients with newly diagnosed epilepsy but excluded those diagnosed with ASD prior to epilepsy. A non-epilepsy comparison group was matched to each case in terms of age and sex. We calculated the incidence of epilepsy in patients with ASD and hazard ratio (HR) to estimate the risk of epilepsy in association with ASD in cohort 1, and the reverse in cohort 2. In cohort 1, the incidence of epilepsy was 13.7 in the ASD group and 1.3 in the non-ASD group (per 1000 person-years). The adjusted HR for epilepsy was 8.4 (95 % CI 5.5-12.7) in the ASD group when compared with the non-ASD group. In cohort 2, the incidence of ASD was 3.4 in the epilepsy group and 0.3 in the non-epilepsy group (per 1000 person-years). The adjusted HR for ASD was 8.4 (95 % CI 6.2-11.4) in the epilepsy group when compared with the non-epilepsy group. A bidirectional association was, therefore, found to exist between ASD and epilepsy. These findings implicate that ASD and epilepsy probably share common risk factors. However, further studies are required to reveal more detail on the mechanism of this bidirectional association.

Parent-reported patterns of loss and gain in communication in 1- to 2-year-old children are not unique to autism spectrum disorder

We compared loss and gain in communication from 1 to 2 years in children later diagnosed with autism spectrum disorder (n = 41), language impairment (n = 110) and in children with typical language development at 7 years (n = 831). Participants were selected from a prospective population cohort study of child language (the Early Language in Victoria Study). Parent-completed communication tools were used. As a group, children with autism spectrum disorder demonstrated slower median skill gain, with an increasing gap between trajectories compared to children with typical development and language impairment. A proportion from all groups lost skills in at least one domain (autism spectrum disorder (41%), language impairment (30%), typical development (26%)), with more children with autism spectrum disorder losing skills in more than one domain (autism spectrum disorder (47%), language impairment (15%, p = 0.0003), typical development (16%, p < 0.001)). Loss was most common for all groups in the domain of 'emotion and eye gaze' but with a higher proportion for children with autism spectrum disorder (27%; language impairment (12%, p = 0.03), typical development (14%, p = 0.03)). A higher proportion of children with autism spectrum disorder also lost skills in gesture (p = 0.01), sounds (p = 0.009) and understanding (p = 0.004) compared to children with typical development but not with language impairment. These findings add to our understanding of early communication development and highlight that loss is not unique to autism spectrum disorder.

Reported History of Developmental Regression and Restricted, Repetitive Behaviors in Children with Autism Spectrum Disorders

OBJECTIVE

Previous research on developmental regression in youth with autism spectrum disorders (ASD) has often been limited by the definition, assessment, and methodology used to evaluate and describe regression. This study sought to overcome these limitations by examining the prevalence, timing, and correlates of documented cases of developmental regression in a large, epidemiological sample of youth with ASD.

METHOD

Utilizing a population-based surveillance methodology, this study includes 862 youth with ASD identified through abstraction and clinician record review.

RESULTS

Approximately 21% of the sample had developmental regression documented in their medical or educational records with the mean age of regression being 24.2 ± 14.3 months. Youth with ASD and a history of regression were more likely to have comorbid intellectual disability, a prior community diagnosis of ASD, and be eligible for educational services as a student with autism. Youth with a documented history of regression also had higher rates of restricted, repetitive behaviors, such as stereotyped speech, nonfunctional routines/rituals, and sensory interests.

CONCLUSION

Results suggest that youth with a history of regression are not only more likely to have comorbid intellectual disability but are also are more likely to have been previously diagnosed with ASD in the community, suggesting that development regression may play an important role in identifying children who are at the risk for ASD and need evaluation. Higher rates of restricted, repetitive behaviors in youth with a documented history of regression may also provide important insights into the relationship between ASD and developmental regression.

Preschoolers with Autism Spectrum Disorder Followed for 2 Years: Those Who Gained and Those Who Lost the Most in Terms of Adaptive Functioning Outcome

Clinical predictors of 2-year outcome in preschoolers with ASD were studied in a population-based group of very young children with ASD (n = 208). Children who gained the most (n = 30) and lost the most (n = 23), i.e., increased or decreased their adaptive functioning outcome according to the Vineland Composite Score between study entry (T1) and follow-up (T2), 2 years later were compared. Individual factors that differed significantly between the two outcome groups were cognitive level, age at referral, not passing expected milestones at 18 months, autistic type behavior problems and regression. However, logistic regression analysis showed that only cognitive level at T1 (dichotomized into IQ < 70 and IQ ≥ 70) made a unique statistically significant contribution to outcome prediction (p = <.001) with an odds ratio of 18.01. The findings have significant clinical implications in terms of information at diagnosis regarding clinical prognosis in ASD.

Temporal lobe connects regression and macrocephaly to autism spectrum disorders

Interictal electroencephalogram (EEG) abnormalities are frequently associated with autism spectrum disorders (ASD), although their relationship with the clinical features of ASD, particularly the regressive onset, remains controversial. The aim of this study was to investigate whether the characteristics of interictal EEG abnormalities might help to distinguish and predict definite phenotypes within the heterogeneity of ASD. We reviewed the awake and sleep interictal EEGs of 220 individuals with idiopathic ASD, either with or without a history of seizures. EEG findings were analyzed with respect to a set of clinical variables to explore significant associations. A brain morphometry study was also carried out on a subgroup of patients. EEG abnormalities were seen in 154/220 individuals (70%) and were mostly focal (p < 0.01) with an anterior localization (p < 0.001). They were detected more frequently during sleep (p < 0.01), and were associated with a regressive onset of ASD (p < 0.05), particularly in individuals with focal temporal localization (p < 0.05). This association was also stronger in regressive patients with concurrent macrocephaly, together with a relative volumetric reduction of the right temporal cortex (p < 0.05). Indeed, concurrence of temporal EEG abnormalities, regression and macrocephaly might possibly define a distinct endophenotype of ASD. EEG-based endophenotypes could be useful to untangle the complexity of ASD, helping to establish anatomic or pathophysiologic subtypes of the disorder.

Emergence of autism spectrum disorder in children from simplex families: relations to parental perceptions of etiology

Current research describes a four-category scheme of Autism Spectrum Disorder (ASD) onset: early, regressive, plateau, delay + regression. To replicate prevalence of different onset types, ASD onset (per the Autism Diagnostic Interview--Revised) was examined in a large North American sample; for a subset, parents' causal beliefs were ascertained via the Revised Illness Perception Questionnaire to examine potential associations with ASD-onset types. Onset rates were similar across samples, with a slightly higher proportion of children in the subsample categorized with regression. Top-rated causes of ASD were genetics, brain structure, will of God, toxins in vaccines, and environmental pollution. Parents reporting regression more often believed that toxins in vaccines caused ASD. Influences on treatment selection and broader public-health ramifications are discussed.

What do home videos tell us about early motor and socio-communicative behaviours in children with autistic features during the second year of life--An exploratory study

BACKGROUND

Little is known about the first half year of life of individuals later diagnosed with autism spectrum disorders (ASD). There is even a complete lack of observations on the first 6 months of life of individuals with transient autistic behaviours who improved in their socio-communicative functions in the pre-school age.

AIM

To compare early development of individuals with transient autistic behaviours and those later diagnosed with ASD.

STUDY DESIGN

Exploratory study; retrospective home video analysis.

SUBJECTS

18 males, videoed between birth and the age of 6 months (ten individuals later diagnosed with ASD; eight individuals who lost their autistic behaviours after the age of 3 and achieved age-adequate communicative abilities, albeit often accompanied by tics and attention deficit).

METHOD

The detailed video analysis focused on general movements (GMs), the concurrent motor repertoire, eye contact, responsive smiling, and pre-speech vocalisations.

RESULTS

Abnormal GMs were observed more frequently in infants later diagnosed with ASD, whereas all but one infant with transient autistic behaviours had normal GMs (p<0.05). Eye contact and responsive smiling were inconspicuous for all individuals. Cooing was not observable in six individuals across both groups.

CONCLUSIONS

GMs might be one of the markers which could assist the earlier identification of ASD. We recommend implementing the GM assessment in prospective studies on ASD.

Adjudicating non-knowledge in the Omnibus Autism Proceedings

After 5600 families of children diagnosed with autism filed claims with the National Vaccine Injury Compensation Program in the United States, the court selected 'test' cases consolidated into the Omnibus Autism Proceedings, held from 2007 to 2008, to examine claims that vaccines caused the development of autism. The court found all of the causation theories presented to be untenable and did not award damages to any parents. We analyze the Omnibus Autism Proceedings as a struggle within the scientific field between the scientific orthodoxy of the respondents and the heterodox position taken by the plaintiffs, suggesting that the ruling in these cases helped to shore up hegemony on autism causation. Drawing on the literature on non-knowledge, we suggest that only the respondents had enough scientific capital to strategically direct non-knowledge toward genetic research, thereby foreclosing the possibility of environmental causation of autism. The plaintiffs, who promote a non-standard ontology of autism, suggest that the science on autism remains undone and should not be circumscribed. In analyzing the Omnibus Autism Proceedings with field theory, we highlight the way in which scientific consensus-building and the setting of research agendas are the result of struggle, and we show that the strategic deployment of non-knowledge becomes a major stake in battles for scientific legitimacy and the settling of scientific controversies.

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".

Social visual engagement in infants and toddlers with autism: early developmental transitions and a model of pathogenesis

Efforts to determine and understand the causes of autism are currently hampered by a large disconnect between recent molecular genetics findings that are associated with the condition and the core behavioral symptoms that define the condition. In this perspective piece, we propose a systems biology framework to bridge that gap between genes and symptoms. The framework focuses on basic mechanisms of socialization that are highly-conserved in evolution and are early-emerging in development. By conceiving of these basic mechanisms of socialization as quantitative endophenotypes, we hope to connect genes and behavior in autism through integrative studies of neurodevelopmental, behavioral, and epigenetic changes. These changes both lead to and are led by the accomplishment of specific social adaptive tasks in a typical infant's life. However, based on recent research that indicates that infants later diagnosed with autism fail to accomplish at least some of these tasks, we suggest that a narrow developmental period, spanning critical transitions from reflexive, subcortically-controlled visual behavior to interactional, cortically-controlled and social visual behavior be prioritized for future study. Mapping epigenetic, neural, and behavioral changes that both drive and are driven by these early transitions may shed a bright light on the pathogenesis of autism.

Regression in autism spectrum disorders

Since the Journal of Paediatrics and Child Health was first published, there has been substantial change in the field of autism spectrum disorders (ASDs) with an exponential increase in the amount of funded and published research. In this paper, we focus on regression in children with ASD, a phenomenon that remains poorly understood. We discuss the implications of what we know about regression in ASD for the way we think about ASD more broadly and for paediatric practice.

Plasma levels of alarmin IL-33 are unchanged in autism spectrum disorder: a preliminary study

The pathogenesis of autism spectrum disorder (ASD) is unknown, and the immune system has been appointed to play an important role. The interleukin 33 (IL-33), a member of the IL-1, may act as an alarmin. This study aimed to evaluate plasma levels of IL-33, sST2, and IL-1β in 30 patients with ASD in comparison with 18 controls matched by gender, age and maternal age at childbirth. Patients did not differ from controls in IL-33, sST2, and IL-1β plasma levels. Alarmin levels were not correlated with age, and neither was influenced by clinical parameters. Our results undermine the role of IL-33/ST2 in ASD.

Brief report: regression timing and associated features in MECP2 duplication syndrome

The aim of this study was to determine the frequency, timing, and associated features of developmental regression in MECP2 duplication syndrome. We also examined whether duplication size was associated with regression. Comprehensive psychological evaluations were used to assess 17 boys with MECP2 duplication syndrome. Information about regression was gathered via parent report. Eight of 17 boys exhibited regression in language skills, while seven of 17 exhibited regression in other skill areas. Regression in "other skill" areas coincided with seizure onset and with a prior autism diagnosis in six of seven participants. Regression was not associated with duplication size. Questions remain as to why some boys regress, and future work is necessary to understand the underlying mechanism(s) that causes regression.

Disruptive CHD8 mutations define a subtype of autism early in development

Autism spectrum disorder (ASD) is a heterogeneous disease in which efforts to define subtypes behaviorally have met with limited success. Hypothesizing that genetically based subtype identification may prove more productive, we resequenced the ASD-associated gene CHD8 in 3,730 children with developmental delay or ASD. We identified a total of 15 independent mutations; no truncating events were identified in 8,792 controls, including 2,289 unaffected siblings. In addition to a high likelihood of an ASD diagnosis among patients bearing CHD8 mutations, characteristics enriched in this group included macrocephaly, distinct faces, and gastrointestinal complaints. chd8 disruption in zebrafish recapitulates features of the human phenotype, including increased head size as a result of expansion of the forebrain/midbrain and impairment of gastrointestinal motility due to a reduction in postmitotic enteric neurons. Our findings indicate that CHD8 disruptions define a distinct ASD subtype and reveal unexpected comorbidities between brain development and enteric innervation.

Corticosteroid therapy in regressive autism: a retrospective study of effects on the Frequency Modulated Auditory Evoked Response (FMAER), language, and behavior

Background

Up to a third of children with Autism Spectrum Disorder (ASD) manifest regressive autism (R-ASD).They show normal early development followed by loss of language and social skills. Absent evidence-based therapies, anecdotal evidence suggests improvement following use of corticosteroids. This study examined the effects of corticosteroids for R-ASD children upon the 4 Hz frequency modulated evoked response (FMAER) arising from language cortex of the superior temporal gyrus (STG) and upon EEG background activity, language, and behavior. An untreated clinical convenience sample of ASD children served as control sample.

Methods

Twenty steroid-treated R-ASD (STAR) and 24 not-treated ASD patients (NSA), aged 3 - 5 years, were retrospectively identified from a large database. All study participants had two sequential FMAER and EEG studies;Landau-Kleffner syndrome diagnosis was excluded. All subjects’ records contained clinical receptive and expressive language ratings based upon a priori developed metrics. The STAR group additionally was scored behaviorally regarding symptom severity as based on the Diagnostic and Statistical Manual IV (DSM-IV) ASD criteria list. EEGs were visually scored for abnormalities. FMAER responses were assessed quantitatively by spectral analysis. Treated and untreated group means and standard deviations for the FMAER, EEG, language, and behavior, were compared by paired t-test and Fisher’s exact tests.

Results

The STAR group showed a significant increase in the 4 Hz FMAER spectral response and a significant reduction in response distortion compared to the NSA group. Star group subjects’ language ratings were significantly improved and more STAR than NSA group subjects showed significant language improvement. Most STAR group children showed significant behavioral improvement after treatment. STAR group language and behavior improvement was retained one year after treatment. Groups did not differ in terms of minor EEG abnormalities. Steroid treatment produced no lasting morbidity.

Conclusions

Steroid treatment was associated with a significantly increased FMAER response magnitude, reduction of FMAER response distortion, and improvement in language and behavior scores. This was not observed in the non-treated group. These pilot findings warrant a prospective randomized validation trial of steroid treatment for R-ASD utilizing FMAER, EEG, and standardized ASD, language and behavior measures, and a longer follow-up period.

Please see related article http://www.biomedcentral.com/1741-7015/12/79

Corticosteroid therapy in regressive autism: Preliminary findings from a retrospective study

Some children with autism spectrum disorders (ASD; 15% to 30% of patients) show a significant and persistent regression in speech and social function during early childhood. There are no established treatments for the regressive symptoms. However, there are some known causes of this type of regression, such as Rett syndrome and Landau-Kleffner syndrome (LKS). In LKS, steroids have been used as a treatment. Some evidence suggests an autoimmune contribution to the pathophysiology of autism (Chez MG, Guido-Estrada N: Immune therapy in autism: historical experience and future directions with immunomodulatory therapy. Neurotherapeutics 2010, 7:293-301, Wasilewska J, Kaczmarski M, Stasiak-Barmuta A, Tobolczyk J, Kowalewska E: Low serum IgA and increased expression of CD23 on B lymphocytes in peripheral blood in children with regressive autism aged 3-6 years old. Arch Med Sci 2012, 8:324-331, Stefanatos G: Changing perspectives on Landau-Kleffner syndrome. Clin Neuropsychol 2011, 25:963-988), raising the possibility that steroids might be a useful therapy for regression in ASD. A retrospective study published in BMC Neurology by Duffy et al. (Duffy, et al: Corticosteroid therapy in regressive autism: A retrospective study of effects on the Frequency Modulated Auditory Evoked Response (FMAER), language, and behavior. BMC Neurol 2014, 14:70) reviewed 20 steroid treated R-ASD (STAR) patients and 24 ASD control patients not treated with steroids (NSA). Improvements in clinical function and in a neurophysiological biomarker were seen in the steroid-treated children pre- to post-prednisolone treatment. This research provides a rationale for a randomized trial with steroid therapy to determine the longer term benefits and complications of steroids in this population.

The melatonin receptor agonist ramelteon effectively treats insomnia and behavioral symptoms in autistic disorder

Children with autism spectrum disorders (ASD), including autistic disorder, frequently suffer from comorbid sleep problems. An altered melatonin rhythm is considered to underlie the impairment in sleep onset and maintenance in ASD. We report three cases with autistic disorder in whom nocturnal symptoms improved with ramelteon, a selective melatonin receptor agonist. Insomnia and behavior, assessed using the Clinical Global Impression-Improvement Scale, improved in two cases with 2 mg ramelteon and in the third case with 8 mg ramelteon. Our findings demonstrate that ramelteon is effective not only for insomnia, but for behavioral problems as well, in patients with autistic disorder.

Autism

Autism is a set of heterogeneous neurodevelopmental conditions, characterised by early-onset difficulties in social communication and unusually restricted, repetitive behaviour and interests. The worldwide population prevalence is about 1%. Autism affects more male than female individuals, and comorbidity is common (>70% have concurrent conditions). Individuals with autism have atypical cognitive profiles, such as impaired social cognition and social perception, executive dysfunction, and atypical perceptual and information processing. These profiles are underpinned by atypical neural development at the systems level. Genetics has a key role in the aetiology of autism, in conjunction with developmentally early environmental factors. Large-effect rare mutations and small-effect common variants contribute to risk. Assessment needs to be multidisciplinary and developmental, and early detection is essential for early intervention. Early comprehensive and targeted behavioural interventions can improve social communication and reduce anxiety and aggression. Drugs can reduce comorbid symptoms, but do not directly improve social communication. Creation of a supportive environment that accepts and respects that the individual is different is crucial.

Patterns of skill attainment and loss in young children with autism

The purpose of this study was to extend the literature on the ontogeny of autism spectrum disorder (ASD) by examining early attainment and loss of specific sociocommunicative skills in children with autism (AUT; n = 125), pervasive developmental disorder not otherwise specified (PDD-NOS; n = 42), nonspectrum developmental delays (n = 46), and typical development (n = 31). The ages of skill attainment and loss were obtained from a caregiver interview. The findings indicated that children with AUT, PDD-NOS, and developmental delays diverged from typically developing children in attainment of sociocommunicative skills early in the first year of life. Loss of at least one skill was reported in a majority of children with AUT and PDD-NOS. Significant delays in attainment of skills were also reported in children who lost skills. The wide variation in skill attainment and loss reported across children indicates that symptom onset and regression may be best represented continuously, with at least some early delay and loss present for a great majority of children with ASD.

Autism in community pre-schoolers: developmental profiles

Autism is often a complex developmental disorder. The aim of the present study was to describe the developmental characteristics of 129 1-4-year-old children (102 boys, 27 girls) referred for clinical assessment (mean age 2.9 years) due to suspicion of autism spectrum disorder (ASD) after community screening at Child Health Care centers. All children were clinically assessed at the Child Neuropsychiatry Clinic (CNC) in Gothenburg by a research team (neurodevelopmental examination, structured interviews and general cognitive and language examinations). Of the 129 children, 100 met diagnostic criteria for ASD (69 with autistic disorder, and 31 with atypical autism/pervasive developmental disorder-not otherwise specified). The remaining 29 children had a variety of developmental disorders, most often attention-deficit/hyperactivity disorder (ADHD), language disorder, borderline intellectual functioning, and intellectual developmental disorder (IDD) with (n=25) or without (n=4) autistic traits (AT). IDD was found in 36% of the 100 children with ASD, and in 4% of the 25 children with AT. Of the children with ASD, 56% had language disorder with no or just a few words at the initial assessment at the CNC, many of whom in combination with IDD. Hyperactivity was found in 37% of those with ASD and in 40% of those with AT. Epilepsy was found in 6% of the total group and in 7% of those with a diagnosis of ASD. Of the latter group 11% had a history of regression, while none of the AT cases had a similar background. When results were compared with a non-screened preschool ASD group of 208 children, referred for ASD intervention at a mean age of 3.4 years, very similar developmental profiles were seen. In conclusion, early community ASD screening appears to systematically identify those children who are in need of intervention and follow-up.

DSM-5 and autism spectrum disorders (ASDs): an opportunity for identifying ASD subtypes

The heterogeneous clinical presentations of individuals with autism spectrum disorders (ASDs) poses a significant challenge for sample characterization and limits the interpretability and replicability of research studies. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) diagnostic criteria for ASD, with its dimensional approach, may be a useful framework to increase the homogeneity of research samples. In this review, we summarize the revisions to the diagnostic criteria for ASD, briefly highlight the literature supporting these changes, and illustrate how DSM-5 can improve sample characterization and provide opportunities for researchers to identify possible subtypes within ASD.