Background: Patients with Parkinson¡¯s disease (PD) have great difficulty in performing two tasks simultaneously, but the neural contribution to the problem has not been identified. In the current study, we investigated the pathophysiology of dual task performance in PD.
Methods: We studied 15 PD patients and 14 healthy controls. Functional MRIs were applied before and after practicing dual tasks with different complexity.
Results: After practice, 12 normal subjects performed all dual tasks correctly. 12 patients performed the simpler dual tasks correctly. However, only 3 patients could perform the more complex dual task correctly. Dual tasks activated similar brain regions in both groups. The bilateral precuneus was additionally activated during performance of dual tasks compared to the component tasks in both groups. Patients had greater activity in the cerebellum, premotor area, parietal cortex, precuneus, and prefrontal cortex compared to normal subjects.
Conclusions: Difficulty in performing two tasks simultaneously in PD patients is likely due to limited attentional resources, defective central executive function, and less automaticity in performing the tasks. Practice can diminish dual task interference and improve performance in PD patients.
- Parkinson's disease
- brain activity
- dual task