Sensorimotor performance in school-age children with autism, developmental language disorder, or low IQ

The purpose of the study was to determine the prevalence of 'soft' motor deficits in school-aged children with either developmental language disorder (DLD), autism (with high IQ [HiAD] or low IQ [LoAD]), or low IQ without autism (LoIQ), and to evaluate the utility of a refined neurological examination to discriminate between these groups. A total of 242 children (74% male), aged 7 or 9 years, were evaluated as part of a longitudinal, multi-institutional study, with a standardized neurological examination that included Denckla's Physical and Neurological Examination for Soft Signs. Most of the scores separated children into two groups defined by nonverbal IQ, with the DLD and HiAD groups performing better than the LoAD and LoIQ groups. Exceptions included motor impersistence and stereotypies, which were more likely in the autistic groups. The neurologists' summary clinical impressions indicated better sensory/motor skills, oromotor skills, and praxis in the HiAD than in the DLD children. Inability/unwillingness to perform tasks was much more frequent in LoAD than LoIQ children.