Alzheimer’s patients may lose driving ability

Iowa, February 9: The loss of driving ability can be a blow to a person's independence, and Alzheimer’s may snatch this privilege from you. A research indicates that there is a drop-off in driving skills of people, who have early or mild levels of cognitive decline.

New cognitive tests may help doctors determine whether people in the early stages of Alzheimer's disease are fit to drive. Jeffrey Dawson, a biostatistician at the University of Iowa College of Public Health, and lead author of the study said "We found that tests that involved visual perception and visual memory were particularly important in preventing driving errors.”

In the study, 40 drivers with early Alzheimer's disease and 115 elderly drivers with no signs of dementia underwent a combination of off-road tests. The test was aimed to measure thinking, movement and visual skills. The participants also drove a 35-mile route in and outside the city. Driving safety errors were monitored by a driving expert, based on a video review of the drive.

The car was also equipped with hidden cameras and specialized sensors to detect changes in acceleration, steering wheel position to assess their performances. The Alzheimer's drivers made an average of 42 errors. The most common mistake was lane violations and failing to go immediately after a light turned green, compared with an average of 33 errors in the healthy group (a 20 percent difference).

Dawson hopes the findings will help create a test to determine if it’s safe for Alzheimer patients to be on the road. The ultimate goal is to combine the most effective tests into one simple exam that doctors could use during routine office check-ups.

Dawson said that "The number of people with dementia is increasing as our population ages, and we will face a growing public health problem of elderly drivers with memory loss. The goal is to prevent crashes while still maximizing patients' rights and freedom to be mobile. By measuring driver performance through off-road tests of memory, visual and motor abilities, we may be able to develop a standardized assessment of a person's fitness to drive."

According to the Alzheimer's Association, dementia, affects an estimated five million people in the U.S. The disease appears to be caused by protein plaques and tangles that accumulate in the brain, damaging cells and chipping away at the victim's cognition and motor skills.

The research is published in the February 10, 2009, print issue of Neurology®. The study was supported by the National Institute on Aging.