Longitudinal patterns of repetitive behavior in toddlers with autism

Abstract

Background Recent evidence suggests that restricted and repetitive behaviors may differentiate children who develop autism spectrum disorder (ASD) by late infancy. How these core symptoms manifest early in life, particularly among infants at high-risk for the disorder, is not well characterized. Methods Prospective, longitudinal parent-report data (Repetitive Behavior Scales-Revised) were collected for 190 high-risk toddlers and 60 low-risk controls from 12 to 24 months age. Forty-one high-risk children were classified with ASD at age 2. Profiles of repetitive behavior were compared between groups using generalized estimating equations. Results Longitudinal profiles for children diagnosed with ASD differed significantly from high- and low-risk children without the disorder on all measures of repetitive behavior. High-risk toddlers without ASD were intermediate to low-risk and ASD positive counterparts. Toddlers with ASD showed significantly higher rates of repetitive behavior across subtypes at the 12 month time point. Repetitive behaviors were significantly correlated with adaptive behavior and socialization scores among children with ASD at 24 months-age but were largely unrelated to measures of general cognitive ability. Conclusions These findings suggest that as early as 12 months age, a broad range of repetitive behaviors are highly elevated in children who go on to develop ASD. While some degree of repetitive behavior is elemental to typical early development, the extent of these behaviors among children who develop ASD appears highly atypical.

Repetitive Behavior in 12-Month-Olds Later Classified With Autism Spectrum Disorder

“…The current findings suggest that clinical characterization of atypical motor stereotypies may augment early identification of ASD in 12-month-olds, a finding that supplements recent evidence that parent report of restricted and repetitive behavior at 12 months differentiates infants who will later develop ASD 36 . The body cluster score is derived from 1) the rate of stereotyped motor mannerisms and 2) the inventory or variety of stereotyped motor mannerisms observed within the given sampling period.…”

“…When considered in conjunction with findings from parent report 36 and in the context of the broader literature delineating observable social communication deficits at 12 months of age, the current data suggest that restricted and repetitive behaviors are observed as early as social communication deficits in infants who later meet diagnostic criteria for ASD. Future investigations into the underlying neural circuitry (e.g., sensory-motor pathways) associated with these atypical behaviors during the first year of life promises to elucidate mechanisms of pathogenesis of ASD.…”

Differences in object sharing between infants at risk for autism and typically developing infants from 9 to 15 months of age

“…In contrast, the reduced object sharing in AR infants at walking ages could have been the result of heightened object perception or perseveration in AR compared to TD infants. AR infants and children with ASD have a substantial bias toward non-social versus social cues and engage in high levels of perseveration and non-functional play with objects compared to TD peers (Bhat et al, 2010; Maestro et al, 2002; Ozonoff et al, 2008; Wolff et al, 2014). For example, during a novel social-object learning task that required infants to spontaneously interact with objects and caregivers, AR infants spent greater time looking at objects than toward caregivers compared to TD infants (Bhat et al, 2010).…”

Development of restricted and repetitive behaviors from 15 to 77 months: Stability of two distinct subtypes?

“…RSM behaviors remained high across these four age points, decreasing 13 by age 9 only in children who had higher non-verbal IQ at age 2. In contrast, IS behaviors 14 started at a low level at age 2 and moderately increased in severity; these behaviors were not 15 predicted by non-verbal IQ and the developmental relation between RSM behaviors and IS 16 behaviors was not explored. Although the children in this study had a wide range of ability 17 levels and general developmental delay, they all had diagnoses of ASD.…”