Frontal-subcortical defects correlate with task switching deficits in Parkinson’s disease

OBJECTIVES: To examine correlation between frontal-subcortical/ parietal-cortical functioning and task switching. METHODS: An experimental study was designed to examine objectives with 80 participants (40 patients with idiopathic Parkinson’s disease (PD) and 40 healthy controls). Patients were recruited from February until September 2016 at Recep Tayyip Erdogan Hospital Pakistan, Muzaffargarh, Pakistan and healthy controls participated from community. Participants were administered Parkinson’s disease cognitive rating scale and Word-Digit categorization task switching experiment. RESULTS: In contrast to healthy controls, (i) PD patients showed impaired cognitive performance on frontal-subcortical and posterior-cortical functions as assessed through PD cognitive rating scale (ii) PD patients showed task switching deficits. Frontal-subcortical defects correlated with task switching deficits. Lesser the scores on frontal-subcortical functions, larger switch costs will appear. Frontal-subcortical defects significantly predicted task switch costs. CONCLUSION: Frontal-subcortical not the posterior-cortical dysfunctions are significant marker of task switching deficits.