Identifying phenotypic and physiological subgroups of preschoolers with autism spectrum disorder.

BACKGROUND: To understand the emergence of symptoms in autism spectrum disorder (ASD), we need to identify the mechanisms that underpin the development of core social skills. Mounting evidence indicates that young children with later ASD attend less to other people, which could compromise learning opportunities with cascading effects. Passive looking behaviour does not tell us about engagement with visual information, but measures of physiological arousal can provide information on the depth of engagement. In the current study, we use heart rate (HR) and heart rate variability (HRV) to measure engagement with social dynamic stimuli in ASD. METHODS: Sixty-seven preschoolers with ASD and 65 typical developing preschoolers between 2 and 4 years of age participated in a study where HR was measured during viewing of social and non-social videos. Using latent profile analyses, more homogeneous subgroups of children were created based on phenotype and physiology. RESULTS: Preschool-aged children with ASD, regardless of their non-verbal, verbal and social competencies, do not differ in overall HR or HRV compared to TD children. However, the ASD group showed a larger increase in HR (more disengagement) than the TD group to later-presented social stimuli. Phenotypic and physiological profiles showed this was primarily the case for children with below average verbal and non-verbal skills, but not necessarily those with more ASD symptoms. CONCLUSION: Children with ASD, especially a subgroup showing moderate cognitive delays, show an increase in HR to social stimuli over time; this may reflect difficulties re-engaging with social information when attention is waning.

Heart rate mean and variability as a biomarker for phenotypic variation in preschoolers with autism spectrum disorder.

Interest in autonomic arousal in autism spectrum disorder (ASD) is increasing; however, reliability of these measures in ASD is unknown, and previously reported associations with social and cognitive abilities are inconsistent. This study assesses heart rate (HR) and HR variability (HRV) in preschoolers with ASD or typical development (TD) while they passively watched naturalistic videos. Measurement reliability, group differences, and the relationship with social and cognitive abilities were evaluated. Seventy one ASD and 66 TD children (2-4 years) provided cardiac data from two sessions. Test-retest intraclass correlations of HR and HRV over a 3-week period were moderate to good in both groups. Groups did not differ in mean level of HR or HRV. Intra-individual variability of HR between video segments within a session was higher in the ASD group, but intraclass correlations of this metric were low. Higher HR related to better language skills in TD children, but not after accounting for age and nonverbal ability. Higher HRV related to better expressive and receptive language in ASD children after controlling for age and nonverbal ability. HR/HRV were not related to social or executive functioning skills and did not explain any additional variance in abilities at a 12-month follow-up visit. In summary, variation in language abilities is associated with HR in the TD group and HRV in the ASD group. While preliminary, these results are promising for consideration of autonomic control as a biomarker for individual differences in ASD and may help us understand the mechanisms that contribute to communication skills. Autism Research 2019, 12: 39-52. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Cardiac activity, such as heart rate and heart rate variability, is linked to a wide range of psychological functions. This study shows that there is an association between heart rate and heart rate variability and language skills in young children with autism spectrum disorder (ASD). These results may help us understand what underlies individual differences in developmental abilities in young children with ASD.

Head circumference as an early predictor of autism symptoms in younger siblings of children with autism spectrum disorder.

Siblings of children with autism have an increased risk for autism spectrum disorders (ASD). As children with autism often exhibit an atypical trajectory of head circumference (HC) growth, HC may be an indicator of vulnerability to autism. This study investigated whether infant siblings of children with ASD (n = 77) with an atypical trajectory of HC growth were more likely than those without an atypical HC trajectory to develop autism symptoms. Results showed that infants who had larger HC at 12 months, and whose HC growth rate decelerated more rapidly between 12 and 24 months were more likely to exhibit autism symptoms than infants with more typical HC trajectories. Among infant siblings of children with autism, atypical HC growth might alert pediatricians to provide screening and/or referral for further evaluation.

Rate of head growth decelerates and symptoms worsen in the second year of life in autism.

BACKGROUND: Longitudinal studies of head circumference growth in infants later diagnosed with autism are needed to understand the accelerated head growth in this disorder. METHODS: We analyzed longitudinal head circumference data from birth to 3 years in 28 children later diagnosed with autism spectrum disorder on the basis of individual growth curve analyses using hierarchical linear models. RESULTS: Head circumference Z scores relative to norms significantly increased in the autism sample from birth to 12 months, but this pattern did not persist beyond 12 months. Rather, the rate of change in head circumference from 12 to 36 months was not different from the normative sample. CONCLUSIONS: These results suggest that a period of exceptionally rapid head growth occurs during the first year of life in autism; after 12 months of age, the rate of head circumference growth decelerates relative to the rate during the first year of life. Studies of behavioral development in infants later diagnosed with autism suggest that the period of acceleration of head growth precedes and overlaps with the onset of behavioral symptoms, and the period of deceleration coincides with a period of worsening of symptoms in the second year of life.

Early social, imitation, play, and language abilities of young non-autistic siblings of children with autism.

Studies are needed to better understand the broad autism phenotype in young siblings of children with autism. Cognitive, adaptive, social, imitation, play, and language abilities were examined in 42 non-autistic siblings and 20 toddlers with no family history of autism, ages 18-27 months. Siblings, as a group, were below average in expressive language and composite IQ, had lower mean receptive language, adaptive behavior, and social communication skills, and used fewer words, distal gestures, and responsive social smiles than comparison children. Additionally, parents reported social impairments in siblings by 13 months of age. These results suggest that the development of young non-autistic siblings is affected at an early age and, thus, should be closely monitored, with appropriate interventions implemented as needed.

Early predictors of communication development in young children with autism spectrum disorder: joint attention, imitation, and toy play.

This study investigated the unique contributions of joint attention, imitation, and toy play to language ability and rate of development of communication skills in young children with autism spectrum disorder (ASD). Sixty preschool-aged children with ASD were assessed using measures of joint attention, imitation, toy play, language, and communication ability. Two skills, initiating protodeclarative joint attention and immediate imitation, were most strongly associated with language ability at age 3-4 years, whereas toy play and deferred imitation were the best predictors of rate of communication development from age 4 to 6.5 years. The implications of these results for understanding the nature and course of language development in autism and for the development of targeted early interventions are discussed.

Family planning and family vision in mothers after diagnosis of a child with autism spectrum disorder.

The diagnosis of a child with autism has short- and long-term impacts on family functioning. With early diagnosis, the diagnostic process is likely to co-occur with family planning decisions, yet little is known about how parents navigate this process. This study explores family planning decision making process among mothers of young children with autism spectrum disorder in the United States, by understanding the transformation in family vision before and after the diagnosis. A total of 22 mothers of first born children, diagnosed with autism between 2 and 4 years of age, were interviewed about family vision prior to and after their child's diagnosis. Grounded Theory method was used for data analysis. Findings indicated that coherence of early family vision, maternal cognitive flexibility, and maternal responses to diagnosis were highly influential in future family planning decisions. The decision to have additional children reflected a high level of adaptability built upon a solid internalized family model and a flexible approach to life. Decision to stop childrearing reflected a relatively less coherent family model and more rigid cognitive style followed by ongoing hardship managing life after the diagnosis. This report may be useful for health-care providers in enhancing therapeutic alliance and guiding family planning counseling.

Early social attention impairments in autism: social orienting, joint attention, and attention to distress.

This study investigated social attention impairments in autism (social orienting, joint attention, and attention to another's distress) and their relations to language ability. Three- to four-year-old children with autism spectrum disorder (ASD; n = 72), 3- to 4-year-old developmentally delayed children (n = 34), and 12- to 46-month-old typically developing children (n = 39), matched on mental age, were compared on measures of social orienting, joint attention, and attention to another's distress. Children with autism performed significantly worse than the comparison groups in all of these domains. Combined impairments in joint attention and social orienting were found to best distinguish young children with ASD from those without ASD. Structural equation modeling indicated that joint attention was the best predictor of concurrent language ability. Social orienting and attention to distress were indirectly related to language through their relations with joint attention. These results help to clarify the nature of social attention impairments in autism, offer clues to developmental mechanisms, and suggest targets for early intervention.

Toddlers with elevated autism symptoms show slowed habituation to faces.

We explored social information processing and its relation to social and communicative symptoms in toddlers with Autism Spectrum Disorder (ASD) and their siblings. Toddlers with more severe symptoms of autism showed slower habituation to faces than comparison groups; slower face learning correlated with poorer social skills and lower verbal ability. Unaffected toddlers who were siblings of children with ASD also showed slower habituation to faces compared with toddlers without siblings with ASD. We conclude that slower rates of face learning may be an endophenotype of ASD and is associated with more severe symptoms among affected individuals.

Memory and response inhibition in young children with single-suture craniosynostosis.

Using two versions of the A-not-B task, memory and response inhibition were assessed in 17- to 24-month-old children with surgically corrected single-suture craniosynostosis (cases) and unaffected children (controls). Children's development and language were initially assessed on average at 6-7 months of age and again at this second visit. Cases and controls performed at equivalent levels on average, with cases performing slightly better than controls on several of the variables measured. However, fewer cases than controls were able to complete the more challenging of the two tasks, which may have predictive significance for later functioning. Children's age and cognitive ability were related to successful performance on the A-not-B task. Among cases, age of cranioplastic surgery was unrelated to performance. Our findings suggest that children with single-suture craniosynostosis show normal development of visual memory and response inhibition in the age range studied here.

Inpatients with eating disorders: demographic, diagnostic, and service characteristics from a nationwide pediatric sample.

OBJECTIVE: This study describes the demographic and clinical characteristics of youth hospitalized with an eating disorder, using the Pediatric Health Information System (PHIS) database. METHOD: Descriptive and inferential statistics were used to examine and compare PHIS inpatients (N = 1,713) with a primary discharge diagnosis of anorexia, bulimia, or eating disorder, not otherwise specified. RESULTS: Of pediatric inpatients with eating disorders, 92% were female and 78% were non-Hispanic white. Their mean age was 15.3 years; 71% had anorexia; 68% had one or more comorbid psychiatric disorders; 53% stayed on a psychiatric unit; the mean length of stay was 15.7 days. Private insurance paid for 55% of hospital stays. Patients without private insurance were more likely than patients with private insurance to be Black or Hispanic and to have comorbid psychiatric diagnoses. CONCLUSION: This study provides new information that can be used by hospitals to anticipate developmental and treatment needs of future inpatients with eating disorders.

Neurocognitive function and joint attention ability in young children with autism spectrum disorder versus developmental delay.

Studies have shown that young children with autism are not impaired on prefrontal tasks relative to what would be expected for their mental age, raising questions about the executive dysfunction hypothesis of autism. These studies did not include ventromedial prefrontal tasks, however. The present study examined whether young children with autism spectrum disorder (ASD) are impaired on ventromedial prefrontal tasks, and whether performance on such tasks is correlated with a core autism symptom, joint attention ability. Seventy-two 3- to 4-year-old children with ASD, 34 3- to 4-year-old developmentally delayed children, and 39 12- to 46-month-old typically developing children, matched on mental age, were administered ventromedial and dorsolateral prefrontal tasks and joint attention tasks. Children with ASD performed similarly to comparison groups on all executive function tasks, indicating that at this early age, there is no autism-specific pattern of executive dysfunction. Ventromedial, but not dorsolateral, prefrontal task performance was strongly correlated with joint attention ability, however. The ventromedial prefrontal cortex is hypothesized to play a role in the development of joint attention and possibly some aspects of the autistic syndrome.