Every hour, someone in the United States is diagnosed with multiple sclerosis (MS), a chronic and progressive disease of the central nervous system. While the severity, symptoms, and course of the disease vary from person to person, one thing remains the same: A diagnosis of MS is not the blow that it used to be.
Women are two to three times more likely to develop MS than men, and most people are diagnosed between the ages of 20 and 50. The prime cause of MS remains a mystery, but risk factors may include ethnicity, family history, exposure to certain viruses, and low levels of vitamin D.
Nerves Under Siege
In MS, your immune system mistakenly attacks myelin, a fatty substance that insulates your nerves and helps them communicate. Over time, this can lead to scarring and hardening of nerve tissue (known as sclerosis) in the spinal cord, brain, and eyes. This, in turn, can cause pain and weakness in the extremities, among other symptoms. Because the location of the damage is so variable, no two individuals have exactly the same symptoms.
Relapsing-Remitting MS: The Most Common Type
There are four types of MS: clinically isolated syndrome, relapsing remitting, secondary-progressive, and primary-progressive. The vast majority—about 85 percent—of people with MS have relapsing-remitting (RRMS).
Here’s what distinguishes RRMS from the other forms of the disease:
• People with RRMS tend to have more brain lesions on magnetic resonance imaging (MRI) scans, and these lesions contain more inflammatory cells. In contrast, people with primary-progressive MS (PPMS) tend to have more spinal cord lesions, which contain fewer inflammatory cells.
• Relapsing remitting MS is diagnosed earlier than the other forms of the illness.
• Most individuals with relapsting remitting multiple sclerosis eventually progress to secondaryprogressive MS (SPMS), which involves a consistent worsening of symptoms. Flare-ups (periods of intensifying symptoms, also known as relapses or exacerbations) may occur, but are less frequent than in RRMS. Recovery is difficult and symptoms may become chronic. The transition to SPMS generally occurs in people who have had RRMS for at least 10 years.
Symptoms and Complications
In the early stages of RRMS, common symptoms may include vision problems; muscle weakness, stiffness, and spasms; limb numbness and tingling; problems with coordination and balance; and fatigue. Many people notice that certain activities and situations, such as a taking a hot bath, feeling stressed, or being feverish, can trigger a flare-up.
As nerve damage progresses, it's possible to develop eye pain, sensitivity to light, and blind spots; depression, possibly triggered by the debilitating nature of the disease; cognitive problems, such as memory and concentration difficulties; swallowing trouble and slurred speech; urinary and bowel problems; and sexual difficulties. RRMS can be unpredictable. You may face flare-ups that last for days or months. It’s also possible to have a gradual but regular increase in physical and cognitive symptoms over time. Or, you may go for years and years with only mild reminders of the disease.
(Note: Going forward, we will refer to a specific form of MS, such as RRMS or SPMS, only when the issue at hand applies only to that form. Otherwise, we will use the term "MS," which encompasses all forms, as there is overlap in the characteristics of the various types.)
While there’s still no cure for MS, recent advances have dramatically brightened the future for people with the disease. Research shows promise for repairing nerve damage and for improved treatments.
“Twenty-five years ago, there were no medications to slow progression of the disease,” says Edward J. Fox, M.D., Ph.D., director of the MS Clinic of Central Texas in Round Rock. “Now there’s a much greater likelihood of early diagnosis and early treatment, which means the prognosis is a lot better.”