Impact of obsessive-compulsive symptoms in Tourette's syndrome on neuropsychological performance

Although inconsistencies in neuropsychological impairments in Tourette's syndrome (TS) have been discussed with respect to comorbid disorders, such as obsessive-compulsive disorder, few studies have focused on the specific dimensions of obsessive-compulsive symptoms (OCS) related to TS, such as aggression and symmetry. The aim of this study was to explore the impact of specific TS-related OCS on neuropsychological performance.

A series of neuropsychological tasks examining attention and executive functioning were performed in groups of 33 TS participants and 18 healthy controls. The neuropsychological performance of TS with Aggression OCS (n = 11) were compared to TS without Aggression OCS (n = 22) and controls by using MANCOVA controlling for age. In the same way as Aggression, we compared the performance of three groups by Symmetry: TS with Symmetry OCS (n = 14), TS without Symmetry OCS (n = 19) and controls.

TS participants with Aggression OCS tended to make more perseverative errors than those without. Global OCS severity and tic severity did not correlate with any neuropsychological performances. No significant differences were detected between TS participants with and without Symmetry OCS.

Neuropsychological deficits in TS might be affected not by global OCS severity but by specific TS-related OCS.