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Third-party-funded project

Criteria to Predict Driving Ability in Parkinson's Disease

Project management at the University of Würzburg:

Participating scientists:


Currently, motor impairment is the main diagnostic criterion in evaluating driving fitness in PD. Recently, the discussion about "sleep attacks" and daytime sleepiness added a new criterion. Our study aimed to prove whether and to which amount these factors determine driving performance and to compare the results of driving tests in a simulator with results from psychometric tests.

24 PD patients were compared to 24 healthy controls. PD patients were allocated to 3x2 subgroups, according to disease severity (Hoehn&Yahr stages 1-3) and daytime sleepiness (yes/no). Driving performance was measured during two trips in a driving simulator (see picture). Trip 1 provided a series of traffic situations from low to high difficulty. Trip 2 realized a monotonous night-time trip. Furthermore, we captured compensatory behavior by two different instructions in the first trip (with and without having to hurry) and the option of taking breaks in the monotonous trip. Test performance was measured at the "Act-React-Testsystem" (ART-2020).

Preliminary analyses show that PD patients committed more driving errors than controls in trip 1 (m=15.7, SD=10.4 vs. m=9.6, SD=8.2, p=.020), mainly due to acting too slowly and bad lane keeping. Only in easy driving tasks the impairments in lane keeping were significantly associated with the Hoehn&Yahr stages. Under monotony an extreme decrease of performance was evident for PD patients in the Hoehn&Yahr stage 3 and for PD patients with daytime sleepiness. However, PD patients showed significantly more compensatory behavior than controls. At the ART-2020 we identified a general slowdown of PD patients, but rather no significant cognitive impairments.

Thus, both disease severity and daytime sleepiness had significant impacts on driving performance, but were insufficient in predicting driving performance. However, the most important factor seems to be the ability to compensate disease related impairments. Critically, this is not captured by classical psychometric tests.

Key words:
    Parkinson's disease
    driving ability
    driving fitness
    daytime sleepiness
    sudden onset of sleep
    sleep attacks

Projekt period: from 10.2001 to 06.2003

Funding institution:
Sonstige private Mittel ( Deutsche Parkinson Vereinigung, Moselstraße 31, 41464 Neuss )

Preceding project:


Chair of Psychology III (Methods and Traffic Psychology)
Center for Traffic Sciences
Deutsche Parkinson Vereinigung
Neurologische Klinik Augsburg