What Causes MS?
Search for the virus
Epidemiologists have long believed a virus infection is associated with the onset of MS: Our studies on a virus in monkeys that is similar to MS have led us to search for a closely related virus in humans. We have used the monkey virus to screen samples collected from healthy people and people with MS to learn if humans are infected with a virus that resembles the monkey virus.
The results from this research reveal that a greater percentage of people with MS than the healthy controls possess antibodies that react to the monkey virus: This supports our hypothesis. We are now performing molecular testing to detect the genetic signatures of the virus in these volunteers. If successful, our findings could lead to additional therapies to treat MS.
Discovering New Anti-Inflammatory Treatments
The goal of these studies is to determine if lipoic acid (LA) is an effective therapy for treating MS. Dr. Dennis Bourdette has studied LA extensively and has shown that it reduces signs of inflammation. LA also appears to prevent further optic nerve injury in animals with optic neuritis, inflammation affecting the optic nerve and causing poor vision. Drs. Vijayshree Yadav and Rebecca Spain are applying this research to MS treatment, with clinical trials of LA for people with MS.
Dr. Yadav is studying the effect of LA on people with MS after a bout of optic neuritis. She will determine if LA is able to reduce the amount of damage to the optic nerve caused by the inflammation and limit long-term vision loss.
Dr. Spain is assessing the neuroprotective benefits of LA in 50 people with secondary progressive multiple sclerosis (SPMS). She believes that people randomly assigned to take LA will have less aging of their brains and less decline in their function than those taking a placebo. Her two-year trial, sponsored by the Department of Veterans Affairs, is one of the few trials in the country open to people with SPMS.
One consequence of MS attacks is the destruction of myelin, a substance that insulates nerve cell fibers and increases the rate at which they conduct their electrical impulses. This is called demyelination, and it leads to numerous neurological deficits. Finding ways to promote remyelination (the regrowth of myelin) could improve many of the symptoms faced by people with MS.
A major reason why remyelination does not occur in those with more advanced MS is the cells that make myelin, called oligodendrocytes, are destroyed and are not replaced. The cells that can create new oligodendrocytes, called oligodendrocyte progenitors, are found in demyelinated lesions -- but they fail to turn into oligodendrocytes.
The Sherman laboratory discovered that a sugar, called hyaluronan (HA) builds-up in demyelinated lesions in people with MS and in animals with demyelinating diseases. When oligodendrocyte progenitors encounter HA, they use enzymes to break it down into molecules that inhibit the ability of progenitors to mature into myelin-forming oligodendrocytes. However, inhibitors of these specific enzymes can promote remyelination in animals with MS-like conditions.
The Sherman lab team is now testing unique chemical compounds that can block these enzymes in hopes of finding new drugs that can promote remyelination and nervous system repair.
Living Better With MS
Falls & MS
More than 50 percent of people with MS fall each year, and many have been injured by a fall. Imbalance, falls and fear of falling don’t just cause injuries, they also interfere with daily life, preventing people with MS from doing the things they enjoy and used to do. For some, this may mean giving up high heels and skiing; for others, it may mean using a wheelchair.
Dr. Michelle Cameron's early research identified proprioception (the ability to feel your foot placement) as an important cause of imbalance in MS. Using a cane or hiking poles to touch the ground while walking can help people with MS because the cane lets the person know where his or her feet are stepping. Dr. Cameron's recent two-year-long study of imbalance and falls in people with MS discovered that asking a person if he or she fell in the last year is as accurate as many more complex tests for identifying those at risk for falling in the future.
Dr. Cameron is now focusing on preventing falls in people with MS using medications, education and exercise.
Vascular Risk Factors
Recent research involving thousands of people with multiple sclerosis (MS) suggests that vascular disease risk factors such as high blood fats, high blood pressure, diabetes and heart disease can contribute greatly to the worsening of disability in MS.
It is not well understood how vascular conditions accelerate the progress of MS. Researchers believe vascular conditions likely slow the blood flow through the gray matter (brain and spinal cord tissue predominantly containing nerves) that results in decreased ability of nerve cells to produce the energy needed for healthy functioning.
Using one of the most advanced brain magnetic resonance imaging (MRI) techniques available, this study will explore abnormalities in blood flow, blood volume and energy metabolism in the brain’s gray matter. Researchers will study how these changes may be related to disease how MS progresses.
The results of these studies will provide the basis for designing a clinical trial to learn if interventions aimed at improving these risk factors can reduce the risk of disease progression among veterans with MS.