Deficient motor control in children with tic disorder: evidence from transcranial magnetic stimulation.

Decreased motor inhibition was reported in adult patients with tic disorder (TD) using the technique of transcranial magnetic stimulation. Since tics usually begin during childhood, motor threshold, cortical silent period (CSP) and intracortical inhibition/facilitation were measured in 21 TD children and 25 healthy children aged 10-16 years. In TD children motor threshold was normal. The CSP was significantly shortened compared to healthy controls but did not depend on tic localization. Intracortical inhibition and facilitation did not differ between the two groups. This study confirms that the finding of decreased motor control in adult patients also holds true for children wherever the tics in the latter group were located.