Developmental dyspraxia is not limited to imitation in children with autism spectrum disorders
Impaired imitation of skilled gestures is commonly reported in autism. Questions, however, remain as to whether impaired imitation is associated with a more generalized deficit in performance of gestures consistent with a dyspraxia and whether the pattern of errors differs from that observed in typically developing children. To address these questions, praxis in 21 high-functioning children with autism spectrum disorders (ASD) was compared with 24 typically developing controls using a traditional approach in which performance was evaluated through detailed examination of error types. Children with ASD produced significantly fewer correct responses not only during Gesture to Imitation, but also during Gesture to Command and with Tool Use. The pattern of errors in ASD was similar to that of controls with spatial errors being most common in both groups; however, body-part-for-tool errors were more common in children with ASD, suggesting dyspraxia is not entirely attributable to motor deficits. The findings suggest that autism is associated with a generalized praxis deficit, rather than a deficit specific to imitation. In a developmental disorder such as autism, the findings may reflect abnormalities in frontal/parietal–subcortical circuits important for acquisition (i.e., learning) of sensory representations of movement and/or the motor sequence programs necessary to execute them. (JINS, 2006, 12, 314–326.)(Received December 30 2004)
(Revised January 4 2006)
(Accepted January 8 2006)
Key Words: Praxis; Apraxia; Motor skills; Imitation; Gesture; Asperger's.
c1 Correspondence and reprint requests to: Stewart H. Mostofsky, M.D., Department of Developmental Cognitive Neurology, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, 707 N. Broadway, Baltimore, MD 21205. E-mail: firstname.lastname@example.org