If you’re sitting in an MS infusion center as you read this, you already know that multiple sclerosis is a chronic, progressive disease of the central nervous system in which the immune system mistakenly attacks myelin, a fatty substance that insulates your nerves and helps them communicate. Over time, these attacks can cause scarring (known as sclerosis or lesions) and hardening of nerve tissue in the spinal cord, brain, and eyes. The lesions can cause pain and weakness in your extremities, vision issues, and cognitive problems. Because the exact locations of MS damage vary from person to person, so do the severity, symptoms, and course of the disease.
Who’s at Risk
For first-timers at the infusion center, you may still be wondering how and why you ended up with MS. Here are some possible risk factors:
- Being female; estimates vary, but about three times as many women as men have MS.
- Where you live or grew up; MS is more prevalent farther from the equator.
- Northern European ethnicity.
- Family history of the disease.
- Certain genes.
- Exposure to certain infections, including Epstein-Barr, human herpes virus 6, and Chlamydia pneumoniae.
- Low levels of vitamin D.
- Obesity (a recently identified risk).
4 Types of MS
Four forms of the disease have been identified: clinically isolated syndrome (CIS); relapsing-remitting MS (RRMS); primary-progressive MS (PPMS); and secondary-progressive MS (SPMS).
With CIS, you have a first episode of neurological symptoms lasting a minimum of 24 hours, caused by inflammation of or damage to myelin in the central nervous system. Some people who experience CIS go on to develop MS of one form or another, and some don’t.
About 85 percent of people with MS are initially diagnosed with RRMS. Here are factors that distinguish RRMS from other forms of MS, according to the National Multiple Sclerosis Society:
- Diagnosis at an earlier age.
- More brain lesions, with more inflammatory cells, as seen on magnetic resonance imaging (MRI) scans. In contrast, people with PPMS tend to have more spinal cord lesions than brain lesions, with fewer inflammatory cells.
- Most people with RRMS eventually develop SPMS, which entails a steady, sustained worsening of symptoms over time; the transition to SPMS generally occurs after having RRMS for a decade or longer.
Symptoms of RRMS
In the early stages of the disease, such symptoms as blurred or double vision, muscle weakness, stiffness, spasms, tingling and numbness in your limbs, coordination and balance problems, and fatigue are common.
Many people with RRMS notice that certain activities or situations, such as taking a hot bath or being under a lot of stress, seem to trigger flare-ups—periods of intensifying symptoms (also commonly referred to as relapses or exacerbations).
If damage to your central nervous system progresses with RRMS, you may develop health issues ranging from depression and mood changes to difficulties with memory and concentration, urinary urgency and frequency, bowel problems such as constipation, and sexual difficulties.
The ways in which people experience RRMS vary widely. Some have flare-ups, lasting anywhere from days to months before easing up, while others notice gradual but steady physical and cognitive decline over time. Still others live for years with only occasional, small reminders they have MS.
There’s no way to predict what course the illness will take, but with the appropriate therapy, most people with MS do not become disabled, says Brian R. Apatoff, MD, PhD, associate professor of neurology and neuro science at Weill Cornell Medical College and director of the Multiple Sclerosis Institute in New York City. “We have some amazing therapies.”
The outlook is much better than it used to be, Dr. Apatoff notes. “Research in MS is one of the most active areas in the field of neurology, with several new therapies in the pipeline. MS is one of neurology’s bright, shining areas of investigation.”