International Meeting for Autism Research: Profile and Specificity of Motor Deficits in Children with Autism Spectrum Disorder

Profile and Specificity of Motor Deficits in Children with Autism Spectrum Disorder

Friday, May 21, 2010
Franklin Hall B Level 4 (Philadelphia Marriott Downtown)
9:00 AM
L. J. Koenig , Laboratory for Neurocognitive and Imaging Research, Kennedy Krieger Institute, Baltimore, MD
L. R. Dowell , Laboratory for Neurocognitive and Imaging Research, Kennedy Krieger Institute, Baltimore, MD
S. H. Mostofsky , Laboratory for Neurocognitive and Imaging Research (KKI), Departments of Neurology and Psychiatry (JHU), Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, MD
Background: An increasing number of research studies have pointed to motor control as an area of difficulty in children with autism spectrum disorder (ASD) (e.g., Jansiewicz et al., 2006; Fuentes, Mostofsky, & Bastian, 2009). However, critical questions remain regarding the profile and specificity of motor deficits in ASD.
Objectives: To better characterize the profile of motor difficulties associated with autism using the Movement Assessment Battery for Children, 2nd Edition (Movement ABC-2, Henderson & Sugden, 2007), which assesses three different sub-categories of motor functioning: balance, manual dexterity, and aiming/catching; and, to examine the specificity of motor findings in autism by comparing performance of children with ASD with that of typically developing (TD) children as well as that of another control group with developmental motor difficulties – children with Attention Deficit/Hyperactivity Disorder (ADHD).
Methods: Participants included 52 children, ages 8-12 years: 16 with ASD (4 female), 18 with ADHD (4 female), and 19 TD children (5 female). Groups were matched on age, gender, IQ, and race.  ANOVAs were used to examine an effect of diagnosis on total and subtest scores on the Movement ABC-2.  The manual dexterity component requires tasks to be timed by the examiner to determine how rapidly the movements can be performed. As the ASD group presented with significantly lower Processing Speed Index (PSI) scores on the Wechsler Intelligence Scale for Children-4th ed. (WISC-IV, Wechsler, 2003) than ADHD and control subjects, analyses for this component were co-varied for PSI.
Results: Three-group ANOVA revealed a significant effect of diagnosis for the components of balance (F = 3.886, p = .027) and manual dexterity (F = 5.888, p = .005), but not for aiming/catching. Follow-up two group analyses revealed the ASD group showed poorer balance compared to TD children (F = 5.982, p = .02) and a trend towards poorer balance compared to ADHD children (F = 3.919, p = .057), with no significant differences between the ADHD and TD groups.  For manual dexterity, the ASD group showed substantially significant poorer performance compared to TD children (F = 16.059, p < .001), but not those with ADHD; and, there was a trend towards ADHD children showing significantly poorer performance compared to TD children (F = 3.725, p = .063). 
Conclusions: Children with ASD have significant difficulty with both manual dexterity and balance compared to TD children. Comparisons to children with ADHD suggest that impairments in balance, while not as substantial as those in manual dexterity, appear to be more specific to ASD.