Virtual reality store tests treatment for balance disorder
March 18, 2009 4:00 AM
Paula Calabrese, right, tells Sue Whitney about the sensations she experiences as strolls the virtual grocery store.
Paula Calabrese scans the shelves to identify products called to her as she strolls a virtual reality grocery store at UPMC Eye and Ear Hospital as part of a study on why some people have balance problems in certain environments, such as the aisles of stores. The subject walks on a treadmill and guides the cart thorough imagery adapted from a video game.
By Pohla Smith Pittsburgh Post-Gazette
Walking down locker-lined school corridors or cruising grocery store aisles and looking side to side for the products she needs can make Paula Calabrese dizzy and "burpy." So do quick movements like jumping out of bed when the alarm sounds.
But the Oakmont woman never really connected the symptoms -- in fact, she didn't even think of them as symptoms -- until she mentioned the incidents to her primary care physician during her most recent annual physical.
"She suggested I come to [the University of Pittsburgh's] Eye and Ear [Institute] and visit the [Center for Balance Disorders]," said Dr. Calabrese, 67, an educational consultant now working with a leadership initiative at the Woodland Hills School District.
At the balance center she was examined by center director Dr. Joseph Furman, who gave her various tests and then, after reviewing the results, told her something was wrong.
"I said maybe it had something to do with aging," Dr. Calabrese said, laughing. "He said it had nothing to do with aging."
Rather, Dr. Furman told her, there appeared to be two problems.
One had to do with the otoconia, crystals on the tiny hairs in the inner ears that help respond to gravity. Those otoconia can get displaced, causing a sensation of spinning.
The other problem appeared to be visual in nature. Movement in Dr. Calabrese's peripheral field of view may have contributed to imbalance.
Dr. Furman first suggested medication, but Dr. Calabrese didn't like that option.
As a second option, he suggested physical therapy for balance disorders. She decided to enter an ongoing National Institutes of Health-funded trial within the medical school and UPMC's Department of Otolaryngology. Called the Virtual Reality Treatment for Balance Disorders Study, it has a control group of patients taking conventional physical therapy for imbalance and another group of patients undergoing treatment in a sort of life-size video game.
All the participants go through a series of balance and mobility tests and fill out surveys on dizziness-producing activities before and after their participation.
Dr. Calabrese landed in the virtual reality part of the study, which was designed by a group of researchers led by Dr. Sue Whitney, principal investigator on the grant. The group also includes Dr. Pat Sparto, director of the Medical Virtual Reality Center and a physical therapist with a Ph.D. in biomedical engineering; Dr. Furman; and Dr. Mark Redfern, associate dean for research in Pitt's School of Engineering.
The game, constructed from the software of Unreal Tournament with artwork by students from the Art Institute of Pittsburgh, projects three-dimensional, moving images of a grocery store onto three screens that surround a typical grocery cart fastened to a treadmill. The goal is to find a new way to treat dizziness and imbalance.
The patient "shopper," hooked to a safety harness, can push the cart at whatever speed he or she wants up to about 3 mph while traveling up and down 16 aisles of increasing difficulty. Easier aisles are stocked with larger products like big boxes of cereals, while the harder ones are home to smaller products like soup and vegetable cans.
While moving through the aisles, the patient is directed by Dr. Whitney, who holds a Ph.D. in education, a physical therapist and a researcher at the Medical Virtual Reality Center. The patient must point out various products located on shelves to either the left or right and anywhere from the top shelf to the bottom.
"What we have noticed here is optic flow [movement of the visual field]; that it's all this stuff that moves past you that's very disorienting," Dr. Whitney said, with Dr. Calabrese nodding in agreement. "We think that's what is [causing the balance problems], and that's part of what we're trying to learn. We ask Paula and others what bothers them in this store, and we're trying to get some sense of what it is so we can ... better simulate it here and gradually get them used to handling it."
The game, in which each participant has six sessions, has had mixed success.
Asked if she had noticed any improvement in her dizzy episodes after she had completed her six sessions, Dr. Calabrese hedged.
"I think it's made a difference," she said. "While I'm not cured, I know things that I should not do. Quick movements are upsetting: bending down and getting up real fast, jumping out of bed real fast. Those sudden movements."
Still, what Dr. Whitney observed resulted in two helpful suggestions for Dr. Calabrese. Dr. Furman prescribed, for a couple months' duration, an anti-anxiety drug called clonazepam to be put under her tongue twice a day and, Dr. Calabrese said, "that seems to have made it subside." Also, while doing her shopping, Dr. Calabrese wears soft bracelets called sea bands, which put pressure on an acupressure point on each wrist by means of a plastic stud.
"It sounds weird, but it makes a difference," she said. Sea bands are often used for seasickness.
Other study participants have noticed much greater improvement from the virtual reality part of the study.
"We have a woman whose results I thought were pretty wild," Dr. Whitney said. "She couldn't go into grocery stores before; it made her pretty sick; and now she can do that without any problems. So that was pretty dramatic to me.
"We've had that happen with two people [out of the first 12 test subjects]. What we don't know is who it can help a lot; who it can help a little bit; and who it doesn't help at all."
Dr. Whitney hopes that by the time the two-year study is completed about a year from now and the results of the game participants have been compared to those of the control group, she'll know.
If a person is experiencing imbalance or dizziness, the experts recommend seeing a primary care physician, because many cases are due to something other than inner ear problems and might require examination by a different kind of specialist.p>
Pohla Smith can be reached at firstname.lastname@example.org or 412-263-1228.