Most people can see how physical factors can affect driving performance.
While physical problems in MS have long been recognized, doctors now realize that about half to two-thirds of patients also have difficulty with mental functions such as thought processing. In other conditions affecting memory and thinking, including Alzheimer's disease and head injury, driving can be risky. If there are concerns about driving competence, these should be addressed by appropriate individual assessment. Response time to conditions resembling those in typical traffic was slightly slower in the MS patients with mental impairment. More than one-third were at moderate to high risk for driving accidents, even though they did not have significant physical limitations.