How does dementia affect driving in older patients?

Driving is a complex activity that always becomes impaired at some point in older adults with degenerative dementia. Over time, disruption of the visual processing circuits of the brain that link the occipital and prefrontal regions, particularly in the right hemisphere, leads to increasing degrees of driving impairment that ultimately preclude safe driving. Neuropsychological tests of visuospatial ability, executive function and attention that tap into the integrity of these brain regions provide the clinician with important information regarding the need for a formal determination of driving competence. Enhancement of cognitive function in these domains through anti-dementia therapy and exercise may partially mitigate risk; however, all drivers with dementia must ultimately retire from driving when dementia becomes moderately severe, and often in earlier stages of the illness. Future efforts to improve screening tests for hazardous driving and to develop interventions to help prolong the time that drivers with mild dementia can continue to drive safely are needed for our increasingly aged and mobile population.