Longitudinal Two-Year Follow-Up of Updating and Flexibility Functions in Drivers with Parkinson’s Disease: Preliminary Results

This paper outlines the preliminary results of a longitudinal follow up at two years interval (t0 versus t2) in 10 drivers with mild to moderate Parkinson’s disease (PD) and 10 matched controls. Changes of (1) driving habits assessed by a questionnaire, (2) neuropsychological performances measured by a set of cognitive tests and (3) cognitive abilities while driving using a simulator, were analyzed. Two types of changes were observed: the decline over time in PD group at two years interval and the appearance of some deficits in PD patients (compared to controls) at the second assessment (t2). These deficits were not observed at the first one (t0). The results showed that PD patients had changed their driving habits over time (reduction of mileage, more avoidance, underestimation of their own driving competency). The cognitive status of PD patients remained relatively stable over time, except for the Trail Making Test performances (part A and part B) which declined. A deficit for the TMT-part A in PD patients, compared to controls, appeared at t2. The data from driving simulator showed no significant decline in PD patients for both updating and flexibility performances. However, a deficit in flexibility appeared at t2 in PD patients, as demonstrated by their poorer performances on the flexibility cost. The authors' data suggest that flexibility may be significantly affected in PD patients with more advanced disease. The small size on their sample does not allow them any conclusion on updating function in both PD patients and controls.