A recent study published in the American Journal of Managed Care (AJMC) says that a new potential test, known as virtual reality (VR) Optical Flow Perturbations, could be used to predict early balance problems in patients with multiple sclerosis (MS).
Scientists in the @UNC_SOM are using virtual reality to help detect balance problems in people with multiple sclerosis. Learn about the VR-based test and how #UNC hopes to help patients reduce their risk of falling https://t.co/MCl42V9xcP
— UNC-Chapel Hill (@UNC) March 24, 2020
Multiple sclerosis, an autoimmune disease, is a disabling disease of the brain and spinal cord where the autoimmune system starts attacking the protective sheath (myelin) around the neurons making it increasingly difficult to connect with and operate rest of body. A person with MS feels poor balance or coordination, blurred vision, speech problems, bladder complications, sexual problems, and progressive muscle loss.
The condition can occur in young children or older adults but is most common in adults aged 20 to 50. According to an estimation report from the National MS Society (NMSS), almost 1 million people are living with MS in the United States which is more than double than previous reports. The society also reported that 2.3 million people have been diagnosed with MS globally.
The researchers used a virtual reality system which is a computer technology to produce a stimulating environment that submerges a person in digital 3D surroundings. It aims to generate an image and content that seem real in presence through senses.
The team collected 14 patients of MS and made a scenario for them through the VR system in which they felt like they were suddenly falling as they walked on a treadmill.
The researchers analyzed four different reactions by using four different methods.
Foot Placement Kinematics: A total force of motion that influences jumping or landing mechanics (heel-toe foot placement)
Gait Variability: A measurable feature of walking
The Margin of Stability: It can calculate four borders including anterior, posterior, lateral and medial. The team focused on the lateral boundary of the base that involved the measurement of a response of the foot touchdown.
Sensory Organization Test: This test helps to identify small differences and changes in the functioning of balance.
The results of the virtual reality test suggested higher variabilities according to the ages of the patients. The findings say that the 29.1% patients had a higher step width variability whereas 17.2% of the people with MS had the higher mediolateral center of mass variability. Furthermore, 21.4% of the patients had mediolateral seventh cervical vertebra variability. The cervical spine comprises of seven vertebrae located in the base of the skull. It works to support the skull, protecting the spinal cord and allowing the head to move back and forth.
The author of the study Jason Franz, Ph.D., assistant professor of biomedical engineering, University of North Carolina, says:
When we walk around, our brains use a variety of sensory feedback channels, including force sensors in our feet, to guide our movements and make corrections from one step to the next. But in people with MS, those force sensors can become less reliable, so people need to rely more on other channels, especially vision.
Can Optic Flow Perturbations Detect Balance?
The team tested the subjects with or without perturbations while the patients were viewing a virtual hallway during walking on a treadmill.
Finding 1: The team conducted an unperturbed walking test on people with MS and found that there were not any significant differences in controls of the patient’s step width, length or any other specific divisions.
Finding 2: The researchers suggested that VR optic flow perturbations might be used as a potential test for the patients of MS to figuring out the prior stage of the disease including equilibrium problems.
Dr. Franz says:
During normal walking without VR – even with our sophisticated lab equipment including a battery of 3D motion capture cameras – we could not effectively distinguish people with MS from the healthy, age-matched individuals. So this perturbed-walking approach could have a lot of important clinical and translational applications.
Further researches are still needed for this technology to be tested according to the age of the patients, sense of balance problems and state of the illness.
Health Units reached out to Dr. Franz and asked him how much time it will take for the VR test to come into clinical practice for the patients of MS. He says:
From this study, we gained very valuable and promising insight into the potential use of virtual reality to detect pre–clinical balance impairment that might go otherwise undetected. However, this was only an early, proof-of-concept study to inspire future clinical opportunities. As with any new discovery, it’s hard to forecast where these findings go from here. But, we hope our findings will serve to inspire the development of innovative tests that could provide some future clinical benefit.