Relationships between cognitive functions and driving behavior in Parkinson's disease.

Alterations in cognitive functions in Parkinson's disease (PD) have been reported even in mild stages of the disease. These functions may play a role in complex daily activities, such as driving. This article provides an overview on the relationships between cognitive functions and driving behavior in PD in driving simulator and on-road studies. The role of attention, executive functions, visual memory, visuospatial construction and information processing speed is discussed. In driving simulator studies, driving performances were correlated with several neuropsychological measures, especially those of Trail Making Test (TMT), Brixton and Symbol Digit Modalities Test. In on-road studies, TMT, Useful Field Of View and Block Design tests appear as good predictors of driving performances. Most of these tests are also relevant to driving in Alzheimer's disease and traumatic brain injury.