Hannes Devos, PhD, PT, assistant director, Driving Stimulation Laboratory, assistant professor, departments of physical therapy, neurology, ophthalmology and School of Graduate Studies, Georgia Regents University, Augusta.
Here’s a difficult conversation: You’re an adult having to tell your mother or father that he/she shouldn’t drive anymore…or a spouse having to give your wife or hubby the same message. This is often the case after someone has had a stroke…which doesn’t make the conversation (or the decision about whether continued driving is safe) any easier. A few years ago, Daily Health News reported on an interesting study that potentially offered practical help in easing you through that tough conversation—a series of three relatively simple tests that can identify who would and who wouldn’t be likely to pass a typical driving road test. All three tests take only 15 minutes total, and the results are a good (but not perfect) indication of who would be a safe driver after a stroke. Besides sparing you from a wrenching argument with a hurt, defensive and very possibly angry parent or spouse, this might also spare the stroke survivor from having to try to prepare for and get through an official road test—as he or she may be required to do after a stroke—and ultimately fail it. When we last reported on these tests, they were not yet available in the US. Now they are.
Before we get to the tests, the first thing to know is that for many people, driving is still safe after a stroke—depending, of course, on the amount and type of damage done and the success of rehabilitation therapy.
According to the lead author of the study, Hannes Devos, PhD, PT, in the department of physical therapy at Georgia Regents University in Augusta, much depends on the area of the brain that’s affected. If the stroke took place in the temporal lobes, which are key to the ability to perceive and understand information, a stroke survivor might see a street sign and be able to read the words…yet not know what they mean. If it’s the occipital lobes, which receive and organize input from the eyes, that are affected, then vision might be impaired. And if the stroke occurred in the frontal lobes, where higher organizational function is maintained, then judgment, problem-solving ability and motor skills—all obviously vital to safe driving—might be lacking.
Making things even more difficult is the fact that some stroke patients are not aware, or not fully aware, of their deficits, Dr. Devos said. “For example, they may think that nothing serious is wrong with the way their body works even when muscles on one side of the body are barely working at all, so they don’t comprehend what’s dangerous or what must be avoided,” he said. Unfortunately, strokes can be cruel that way. But how can all of this—the physical and the psychological—be sorted out in just 15 minutes to determine who should and who shouldn’t be driving?
Out of the 1,728 people studied, 54% passed their road tests, with the best determinants of success being the following three tests…
• The road-sign recognition test. In this segment, the person being tested is asked to match 12 road signs, where their meaning must be recognized and matched to cards showing particular driving situations—for example, the person might have to match a road sign indicating construction ahead with a card depicting men repairing a road.
• The compass test. This is a test of perception, attention and mental speed that involves placing cards with “vehicles” on them so that the vehicles are lined up properly according to the directions indicated on a second card—a compass with an arrow showing various directions. This tests the ability to understand directions consistently and under pressure.
• The trail-making test part B (TMT B). In this segment, participants are asked to quickly connect circles containing numbers or combinations of the numbers one to 12 and the letters A to L, as in 1-A, 2-B, 3-C. What’s measured here are visual motor abilities and the ability to shift one’s attention.
The tests aren’t perfect, but the authors of the study say that they can correctly identify 80% to 85% of those tested who would make unsafe drivers. Importantly, the tests failed to identify 15% to 20% of unsafe drivers—and researchers point out that they may also fail to identify some safe drivers, as well. But post-stroke road tests could make up these gaps.
For families who are sure or fairly sure that driving should no longer be an activity for a loved one, these tests can be a big help in terms of satisfying everyone involved that getting behind the wheel is just no longer a good idea. The US version of the tests, called Stroke Drivers’ Screening Assessment, is available from the University of Nottingham site. You or your doctor can obtain a copy, but the tests must be administered by a physician, neuropsychologist or occupational therapist.