Stress affects hedonic responses but not reaching-grasping in Parkinson's disease

Stress can transiently increase motor symptoms of Parkinson's disease (PD), but it is unclear whether other behavioural changes associated with PD are also affected. We found that reaching-grasping was impaired in 19 PD patients compared with 19 matched controls, but these impairments were not amplified by stress. However, patients showed a stress-induced reduction of hedonic responses. Stress may amplify those impairments in PD that are not accessible to cognitive control.