What Is Multiple Sclerosis?

Multiple sclerosis (MS) is an inflammatory disease affecting the central nervous system. That means your body’s own immune system attacks your brain and spine. Though our understanding of MS has improved in recent years, we do not yet know what causes the condition. We do know that it tends to strike adults 18 to 40 years of age and affects more women than men. It can affect children. Resulting symptoms include mobility issues, bladder concerns, and cognitive deficits. MS affects about one million Americans. This disease can take a heavy toll on those living with the disease and their loved ones.

Fortunately, MS has become a highly manageable disease over the past 20 years. There is no cure yet. But there are new therapies that can lessen the effects of MS and help to maintain or improve your quality of life.

Signs and Symptoms

Multiple sclerosis symptoms and their severity vary from person to person. New symptoms can last for days or weeks and then improve. Over time, the symptoms of MS can become chronic.

Often the first symptoms are blurred or double vision, loss of color vision, or blindness in one eye. These vision problems are often temporary. You might also experience muscle weakness in your arms and legs, difficulty with coordination and balance, or a "pins and needles" feeling. Heat sometimes causes symptoms to get worse temporarily. You may also experience difficulties with:

Concentration, memory, and judgment: MS can make it difficult to focus, remember things, and process information. The disease generally does not affect intellect in adults. James Sumowski, PhD, leads our MS neuropsychology program.
Urinary problems: Many MS patients have difficulty controlling their bladder. The symptoms vary from person to person. We work with urologists who can help.
Fatigue: This is one of the most common MS symptoms. We can evaluate your fatigue and help you improve your energy level so you can live your life as fully as possible
Mood: Depression and anxiety are very common with MS. These may be your response to the disease itself, or an emotional response to the diagnosis, or both. It can help to talk about your sadness, grief, or anxiety. Our social workers can provide support, and our psychiatrists can offer medical treatment.
Intimacy: MS can affect sexuality, directly and indirectly. Men may have difficulty getting or maintaining an erection. Women may experience pain, numbness, or decreased lubrication. MS can also decrease desire. We can help you work through these issues. If you need more help, we can refer you to our colleagues.

Risk Factors

Researchers do not know what causes MS. We do know some of the factors that can increase your risk of developing MS:

Gender: Adult women are more likely to develop MS than adult men. But among children below age 10, boys are as likely to develop MS as girls.
Genes: Certain genes can increase your risk. While the risk of MS is greater if it is in the family, the familial risk is low (3 to 5 percent).
Geography: Living farther from the equator, in less sunny areas, can increase your risk. The reason for this is unclear. It may be related to preventive qualities of vitamin D, which you can get naturally through sun exposure.
Nutrition: We do not know the exact connection between MS and what you eat. Preliminary studies have suggested certain dietary habits may be linked to MS, but the evidence is insufficient. At Mount Sinai, we are studying the role of diet in MS through new research.
Obesity: Being overweight in childhood and adolescence seems to increase the risk of developing MS, particularly for girls.
Race: Some research has suggested an impact of race on the development of MS as well as prognosis. We are currently studying this topic.
Smoking: This habit increases your risk of developing MS. It also tends to cause the disease to progress more quickly. If you stop smoking, it can slow the disease progression.
Vitamin D: Low levels of vitamin D may contribute to risk.

Over the years, there have been many theories about the causes of MS. Studies have explored these theories, showing that certain things do not lead to MS, such as environmental allergies; exposure to household pets; exposure to heavy metals (including mercury, lead, and manganese); and consumption of aspartame, an artificial sweetener.

Types of MS

MS varies from individual to individual. In general, there are three phenotypes of MS:

Relapsing Remitting MS: This is the most common phenotype of MS, affecting about 85 percent of patients. This type of MS often starts in younger people. It causes periodic attacks of symptoms (called relapses), followed by a period of recovery (called remission).
Primary Progressive MS: This affects 10 to 15 percent of MS patients and is more common in men. With this type, the disease gets slowly worse over time.
Secondary Progressive MS: Many people develop secondary progressive MS after initially being diagnosed with relapsing remitting MS. With this type, you are less likely to have periods of remission. Instead, your symptoms may get slowly worse. You may also still have relapses.

Research and Clinical Trials

Researchers are learning more about the nature of multiple sclerosis. We are developing more treatments, but they do not cure the disease. They can make it easier to live with MS. Mount Sinai participates in a number of clinical trials as well as other research studies