Specificity of dyspraxia in children with autism

Objective: To explore the specificity of impaired praxis and postural knowledge to autism by examiningthree samples of children, including those with autism spectrum disorder (ASD), attention-deficithyperactivity disorder (ADHD), and typically developing (TD) children. Method: Twenty-four childrenwith ASD, 24 children with ADHD, and 24 TD children, ages 8-13, completed measures assessing basicmotor control (the Physical and Neurological Exam for Subtle Signs; PANESS), praxis (performance ofskilled gestures to command, with imitation, and tool use) and the ability to recognize correct handpostures necessary to perform skilled gestures (the Postural Knowledge Test; PKT). Results: Childrenwith ASD performed significantly worse than TD children on all three assessments. In contrast, childrenwith ADHD performed significantly worse than TD controls on PANESS but not on the praxisexamination or PKT. Furthermore, children with ASD performed significantly worse than children withADHD on both the praxis examination and PKT, but not on the PANESS. Conclusions: Whereas bothchildren with ADHD and children with ASD show impairments in basic motor control, impairments inperformance and recognition of skilled motor gestures, consistent with dyspraxia, appear to be specificto autism. The findings suggest that impaired formation of perceptual-motor action models necessary todevelopment of skilled gestures and other goal directed behavior is specific to autism; whereas, impairedbasic motor control may be a more generalized finding.