Oculomotor abnormalities in boys with Tourette syndrome with and without ADHD

Objective: To assess saccadic eye movements in boys with Tourette syndrome (TS) with and without attention-deficit hyperactivity disorder (ADHD), comp aring performance with that of an age-matched group of male controls. Metho d: Three different saccade tasks (prosaccades, antisaccades, and memory-gui ded saccades) were used to examine functions necessary for the planning and execution of eye movements, including motor response preparation, response inhibition, and working memory. The study included 14 boys with TS without ADHD (TS-only), 11 boys with TS and ADHD (TS+ADHD), and 10 male controls. Results: Latency of prosaccades was prolonged in boys with TS (both with an d without ADHD) compared with controls. Variability in prosaccade latency w as greater in the groups of boys with TS+ADHD compared with both the TS-onl y and control groups. Response inhibition errors on both the antisaccade ta sk (directional errors) and memory-guided saccade task (anticipatory errors ) were increased in boys with TS+ADHD compared with those with TS-only. The re were no significant differences among the three groups in accuracy of me mory-guided saccades. Conclusions: Oculomotor findings suggest that TS is a ssociated with delay in initiation of motor response as evidenced by excess ive latency on prosaccades. Signs of impaired response inhibition and varia bility in motor response appear to be associated with the presence of ADHD.