Is Motor Impairment in Autism Spectrum Disorder Distinct From Developmental Coordination Disorder? A Report From the SPARK Study

Abstract

Background: Motor impairments are pervasive in Autism Spectrum Disorder (ASD); however, children with ASD rarely receive a dual diagnosis of Developmental Coordination Disorder (DCD). The Simons Foundation SPARK study engaged families affected by ASD through an online study.

Objectives: The DCD parent questionnaire (DCDQ) was used to assess the prevalence of a risk for motor impairment or DCD in children with ASD between 5 and 15 years of age.

Design: This study utilizes parent reports from a large database of children with ASD.

Methods: A total of 16,705 parents of children with ASD completed the DCDQ. We obtained our final SPARK dataset (n = 11,814) after filtering out invalid data, using stronger cut-offs to confirm ASD traits, and excluding children with general neuromotor impairments/intellectual delays. We compared DCDQ total and subscale scores from the SPARK dataset with published norms for each age between 5 and 15 years.

Results: The proportion of children with ASD at risk for a motor impairment was very high at 86.9%. Children with ASD did not outgrow their motor impairments and continued to present with a risk for DCD even into adolescence. Yet, only 31.6% of children were receiving physical therapy services.

Limitations: Our analysis of a large database of parent-reported outcomes using the DCDQ did not involve follow-up clinical assessments.

Conclusions: Using a large sample of children with ASD, this study shows that a risk for motor impairment or DCD was present in most children with ASD and persists into adolescence; however, only a small proportion of children with ASD were receiving physical therapist interventions. A diagnosis of ASD must trigger motor screening, evaluations, and appropriate interventions by physical and occupational therapists to address the functional impairments of children with ASD while also positively impacting their social communication, cognition, and behavior. Using valid motor measures, future research must determine if motor impairment is a fundamental feature of ASD.

Keywords: Autism; Children; DCD; Diagnosis; Motor; Treatment.

Figure 1

Proportion of children with or without risk for Developmental Coordination Disorder (DCD) in the SPARK dataset. Bars indicate number of samples, whereas the pie chart inset shows the sample proportions of children with or without a risk for DCD.

Figure 2

Proportion of children with or without a risk for Developmental Coordination Disorder (DCD) as a function of age at evaluation in years.

Figure 3

Developmental Coordination Disorder Questionnaire (DCDQ) total scores for girls who are Typically Developing (TD) and girls with Autism Spectrum Disorder (ASD) (top panel) and boys who are TD and boys with ASD (bottom panel) as a function of age at evaluation in years. Data corresponding to TD are adapted from Nakai et al. Solid and dashed bars correspond to TD (Nakai et al) and ASD (SPARK data), respectively. Overlaid shaded boxes represent the score ranges corresponding to indication of Developmental Coordination Disorder (DCD), that is, at risk. All between-group P values were <.001 after Bonferroni corrections.

Figure 4

Developmental Coordination Disorder Questionnaire (DCDQ) subscale scores (control during movement, blue; fine motor, red; general coordination, green) for girls who are Typically Developing (TD) and girls with Autism Spectrum Disorder (ASD) (top panel) and boys who are TD and boys with ASD (bottom panel) as a function of age at evaluation in years. Data corresponding to TD are adapted from Nakai et al . Data corresponding to ASD are based on the SPARK dataset. Solid and dashed bars correspond to TD and ASD, respectively. All between-group P values were <.001 after Bonferroni corrections.