Detecting Alzheimer's in the way you walk

You can learn so much about a person's mind by watching his or her feet.

“People who are focused on cognition largely never watch people move,” Dr. Stephanie Studenski, an expert on walking who was not involved in the dementia studies, told The New York Times. “The tests are all done sitting down. But damage to the [nervous system] is an important shared problem of difficulty with thinking and difficulty with moving.”

Previously, scientists would study walking after a heart attack, stroke or the onset of diseases like Parkinson's. They also thought that slower walking with age was just a fact of life, but the new research shows that some gait changes are due to problems beyond aging.

The studies

The studies differed from previous research in being larger, more detailed and more sophisticated in their measurement of gait. For instance, they used an electronic walkway that used sensors to measure minute changes in walking speed, step frequency, the stride width and its variability. They screened out subjects who had arthritis or other physical problems.

Basel, Switzerland

In one study of 1,100 of the elderly in Basel, Switzerland, participants walked down the walkway once and then walked down it a second time while simultaneously engaged in mental activity: either naming animals or counting every other number backward from 50.

While one 72-year-old woman was able to traverse the walkway easily in the first test, in the second test, she wobbled on her feet and even almost tipped to the side. The researchers then tested her cognitive abilities and found minor impairment.

When people try to perform thinking and movement tasks simultaneously, the researchers were able to see “deficits that you can’t see with the naked eye,” Dr. Stephanie Bridenbaugh, head of the Basel Mobility Center, told The Times. “A lot of times normal walking looked normal, even in people with moderate Alzheimer’s, but if you look at dual tasking, I can detect these problems."

The Times reports:

Her research consistently showed that people who walked more slowly or inconsistently did worse on cognitive tests; the worst walkers had the most severe Alzheimer’s.

Mayo Clinic

A Mayo Clinic study of more than 1,300 subjects without dementia evaluated their gait and cognitive abilities twice, 15 months apart. It found that people who walked a meter slower per second on the second test scored a half point lower on the cognitive tests.

Rotterdam

At Erasmus MC University Medical Center in Rotterdam, the researchers asked more than 1,200 people who had no signs of dementia to do three things: "to walk normally, to walk and turn around halfway through, and to “tandem walk,” in which the heel of one foot is placed directly in front of the toe of the previous foot," reports The Times. They also then underwent cognitive testing to see which types of walking problems were associated with which types of cognitive decline.

People who had trouble with the tandem walking showed problems with fine motor skills. People who made fewer steps per minute had problems with tests of thinking speed. And  people who had variable gaits and walked slowly had poor executive function. None of the walking symptoms correlated with memory problems.

Next steps

The studies raise the question that physical activity could forestall dementia. They also indicate that walking can be used in screening and should become part of routine checkups, just the way doctors listen to a patient's heart.

Related on SmartPlanet:

• Wearing heels alters one's barefoot gait, study says
• Exercise shown to stave off Alzheimer's in high-risk subjects
• First large-scale trial of Alzheimer's prevention drug announced
• $300 million to find out how the human brain perceives
• Study shows sitting too much cuts years off your life
• The missing link between exercise and health
• Study pinpoints how exercise improves brain performance

via: The New York Times

photo: pedrosimoes7/Flickr

This post was originally published on Smartplanet.com