April 17, 2014
By Joe Stumpe
|Jessie Huisinga, Ph.D.|
The effects of multiple sclerosis (MS) on walking and balance are familiar to those who live with the disease, but they're not completely understood, even by doctors.
"There's really no consistent way for a neurologist to measure what those walking and balance problems are," said Jessie Huisinga, Ph.D., an assistant professor of physical therapy and rehabilitation science. "Pretty much all the neurologist can do is visually observe the patient walking and have them stand with their eyes open and closed. These tests aren't very specific."
Huisinga is leading research into the creation of a much more detailed mobility assessment for people with MS.
The goal is to provide clinical researchers with the tools to determine which experimental treatments actually improve walking and balance problems.
With MS, inflammation damages nerve cells within the brain and spinal cord, which disrupts the nervous system. Up to 85 percent of patients with MS report problems with their walking and balance; problems with vision, speech,and emotions are other common symptoms.
There is no known cure for MS, and medications often come with adverse side effects. About 2.5 million people worldwide have been diagnosed, and women are two to three times more likely to get the disease.
The research, which is being done at the Landon Center's Human Performance Laboratory is designed and overseen by Huisinga, with the help of research engineer Adam Bruetsch and graduate research assistant Sahibjit (Sunny) Ranu. Bruetsch has a master's degree in mechanical engineering. Ranu is working on a master's in bioengineering.
Since spring of 2013, the team has been bringing MS patients and healthy control subjects to the lab for a battery of tests that take about two hours to complete.
Before the tests begin, each subject's lower extremities are fitted with more than 30 sensors. Some of the sensors are monitored by high-speed infrared cameras and others feed information about the subject's body movements into the lab's computer. Motion capture software is used to create an animated model, a process identical to the way video games and animated movies are created.
In the first test, subjects are asked to stand still with their hands folded across their chests, then do the same thing with their eyes closed; while counting backward in intervals of three; and while standing on a soft foam pad.
It's known that people with MS are more likely to fall when doing more than one thing at a time.
"Patients with MS are more adversely affected by one type of external stimulus than another," Bruetsch said. "For some, the counting would be an issue, others would be more affected by closing their eyes." To measure the effects, sensors measure any swaying that occurs while the subject is standing still. A force platform in the floor captures any change in their body's center of balance.
In the second series of tests, subjects are asked to walk across the floor at moderate, fast, and slow speeds. Then an additional task of counting backward is added. As the sensors track movement, the force platform records how the subjects' feet hit the ground.
Finally, subjects are placed on a treadmill that starts suddenly, and the recording devices capture their efforts to regain their balance. The sensors placed on their legs record whether subjects' muscles are reacting as they should to the stimulus.
Healthy control subjects can complete this test with minimum difficulty. Patients with MS are accompanied by an assistant and wear a safety harness.
The researchers plan to test 80 people with MS, and the same number of healthy subjects who are an approximate age and gender match for the MS patients. The healthy subjects give researchers the "normal" or baseline data from which deviations are measured. A challenge for the project is the wide variety of symptoms and range of severity shown by MS patients.
About half the subjects had been tested by late fall, 2013. Analysis will continue for at least a year after the tests are concluded. The next step is to work with neurologists who treat MS patients with drugs or to undergo physical therapy.
"There's nothing like this currently being used for clinical trial purposes," Huisinga said. "The ultimate goal is to understand the problem to find the best treatment."
Extra: Read how Denice Bruce, Director of Public Affairs at the KU School of Medicine-Wichita, overcame her fear of spandex to participate in research at the Landon Center's Human Performance Laboratory.