The exact etiology of Tourette Syndrome (TS) remains unclear, making the search for impaired neuropsychological functions possibly connected to the underlying cause of TS as important as it is challenging. One neuropsychological domain of interest is fine motor skills.
This study compared fine motor skill performance on the Purdue Pegboard Task (PPT) in 18 children with TS, 24 unaffected first-degree siblings and 20 controls. A set of screening questionnaires was administered to determine comorbid psychiatric illness.
Children with TS, their siblings and controls did not differ significantly in fine motor skills as measured with the PPT. Performance on the PPT was not correlated with tic severity; however, we found an inverse correlation with severity of attention-deficit/hyperactivity disorder (ADHD) symptoms, as assessed by parent reported ADHD symptoms. Children with TS were found to have significantly higher parent reported ADHD symptoms compared to controls, yet only two out of the 18 participants had been diagnosed with ADHD.
This study suggests that fine motor skill impairment in children with TS may be more strongly correlated with comorbid ADHD than to TS and tics.