Low-Contrast Visibility May Be Issue for Parkinson's Drivers

Study suggests patients may be at increased risk for unsafe driving during fog or twilight

09 oct 2009-- Drivers with Parkinson's disease may be more prone to poor vehicle control and crashes while driving in low-contrast visibility conditions due to issues with perception, cognition and motor dysfunction, according to a study in the Oct. 6 issue of Neurology.

Ergun Y. Uc, M.D., of the University of Iowa in Iowa City, and colleagues analyzed data from 67 currently active drivers with mild to moderate Parkinson's disease and 51 controls. Participants drove using a driving simulator under clear conditions and then mildly foggy conditions. During the study, participants reached an intersection where another vehicle posed a crash risk under low-contrast visibility.

The researchers found that drivers with Parkinson's disease had a higher standard deviation of lateral position and lane violation counts than unaffected controls under low-contrast visibility. These measurements increased more in drivers with Parkinson's disease upon the transition from clear to foggy conditions. More drivers with Parkinson's disease crashed at the foggy intersection (76.1 versus 37.3 percent), as their time to first reaction in response to the incursion was longer.

"Our results suggest that a large proportion of drivers with Parkinson's disease may be at further risk for unsafe driving during fog or twilight because of visual, cognitive, and motor impairments," the authors conclude.

Abstract
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