Neuropsychological characteristics of children with Tourette syndrome: evidence for a nonverbal learning disability?

In this study the neuropsychological characteristics of thirty-one 6 to 16-year-old children with Tourette Syndrome (TS) were compared to 20 normal siblings and 10 children with arithmetic disabilities (AD) who were comparable in age and socioeconomic status. Unlike the sibling group, neuropsychological profiles of the TS and AD groups were expected to reflect nonverbal learning disabilities (NLD). The three groups performed generally within the average range on academic and cognitive measures. Like the AD children, the TS group demonstrated poorer performance on written arithmetic tasks with comparatively better word reading and written word spelling. Unlike the AD group, who demonstrated generalized nonverbal deficiencies, children with TS demonstrated reduced performance on visual-motor and expressive language measures as well as measures of complex cognition. These results are suggestive of an "output" subtype of learning disability and support theories that implicate the mesocortical dopaminergic system in the pathophysiology of TS.