Trying to pinpoint cause of elderly’s mobility woes

The first time Mom loses her house keys or momentarily forgets her favorite grandchild’s middle name, family members often panic. Dementia has become such a dreaded focus of old age.

But when Dad needs a walker or Mom trips on the rug, it typically is dismissed as just another reality of growing old.

Although frequently overlooked, mobility problems in older people are as common as cognitive impairments and can be equally debilitating. Some experts estimate that half of all people over 85 have some type of mobility problem including shaky balance and stiffness or frequent falling.

Some of these problems are caused by diseases such as Parkinson’s or arthritis. But for most people, it is impossible to pinpoint a specific cause.

“It’s frustrating,” says Dr. Leslie Wolfson, chairman of the neurology department at the University of Connecticut Health Center. “Most of these people do not fit into a convenient spot.”

Although truly effective strategies for preventing and treating memory loss remain elusive, researchers such as Wolfson think they are closing in on why so many people struggle with muscle control and balance as they age.

And if their hypothesis holds up, Wolfson says doctors soon may be able to predict which patients are at risk of mobility problems and offer early treatment to prevent them.

Many people who suffer from unexplained mobility problems have suffered a series of seemingly harmless and unnoticeable strokes, Wolfson says. Each stroke kills a spot in the brain no bigger than a pinhead. The strokes go virtually unnoticed by the patient but are visible on highly enhanced MRI scans.

The small strokes, researchers think, disconnect the brain’s motor processing ability from its sensory processing ability. When the brain is working properly, the sensory functions such as the eyes and ears help the body to regain balance when one foot trips on a crack in the sidewalk. But when some of the internal computer’s circuits are shut down by small strokes, the person who trips on a sidewalk crack may fall down.

Research has already uncovered evidence of the tiny strokes in people with mobility problems.

Now with a $3-million grant from the National Institutes of Health, Wolfson and his colleagues are trying to map the brains of older volunteers to determine if there is a relationship between mobility problems and tiny strokes in particular regions of the brain.

They then will try to link certain known cardiovascular risk factors, including diabetes, low blood pressure, high blood pressure, old age and genetics, to an increase in the incidence of these potentially debilitating strokes.

“We’re looking at vascular disease risk factors to find out what causes the little strokes,” Wolfson says. “Then we can figure out how to treat [them].”

For example, if it turns out that people with uncontrolled diabetes have more tiny strokes in key areas that affect mobility, researchers will begin to study whether controlling diabetes can prevent the strokes and thus mobility problems. The idea is the same if evidence points to blood pressure problems or other diseases as causes of the strokes.

Wolfson estimates that 20% to 30% of mobility problems are linked to the tiny, silent strokes. Finding a culprit for the strokes could be a first step in keeping a significant number of people on their feet, he says.

But Mary Tinetti, one of the nation’s leading authorities on mobility in older people, is skeptical. The director of the Claude D. Pepper Older Americans Independence Center at Yale University, Tinetti says that as people grow old a combination of factors can interfere with their ability to move.

A person whose vision is clouded by cataracts, has minor memory problems and takes medications that cause drowsiness, for example, can be expected to have trouble balancing, she says.

“I think it is possible to find the multi-factors that lead to people’s walking problems, but my guess is [the cause] is not in one area of the central nervous system,” Tinetti says.

But she says she expects Wolfson’s research will add to a scarce body of knowledge about mobility in older people. The study of mobility issues, she says, is in its infancy, lagging behind the study of memory and cognitive losses in the elderly.

“If you go back 20 or 30 years, someone said cognitive problems are not a normal part of aging,” Tinetti says. “The same thing hasn’t yet happened with mobility.”