Multiple sclerosis is a disease that causes breakdown of the protective covering of nerves. Multiple sclerosis can cause numbness, weakness, trouble walking, vision changes and other symptoms. It’s also known as MS.
In MS, the immune system attacks the protective sheath that covers nerve fibers, known as myelin. This interrupts communication between the brain and the rest of the body. Eventually, the disease can cause permanent damage of the nerve fibers.
Symptoms of MS depend on the person, the location of damage in the nervous system and how bad the damage is to the nerve fibers. Some people lose the ability to walk on their own or move at all. Others may have long periods between attacks without any new symptoms, called remission. The course of the disease varies depending on the type of MS.
There’s no cure for multiple sclerosis. However, there are treatments to help speed the recovery from attacks, modify the course of the disease and manage symptoms.
Types
Some conditions are classified as stages, but multiple sclerosis is classified as types. MS types depend on the progression of symptoms and frequency of relapses. Types of MS include:
Relapsing-remitting MS
Most people with multiple sclerosis have the relapsing-remitting type. They experience periods of new symptoms or relapses that develop over days or weeks and usually improve partially or completely. These relapses are followed by quiet periods of disease remission that can last months or even years.
Secondary-progressive MS
At least 20% to 40% of people with relapsing-remitting multiple sclerosis can eventually develop a steady progression of symptoms. This progression may come with or without periods of remission and happens within 10 to 40 years of disease onset. This is known as secondary-progressive MS.
The worsening of symptoms usually includes trouble with mobility and walking. The rate of disease progression varies greatly among people with secondary-progressive MS.
Primary-progressive MS
Some people with multiple sclerosis experience a gradual onset and steady progression of signs and symptoms without any relapses. This type of MS is known as primary-progressive MS.
Clinically isolated syndrome
Clinically isolated syndrome refers to the first episode of a condition that affects the myelin. After further testing, clinically isolated syndrome may be diagnosed as MS or a different condition.
Radiologically isolated syndrome
Radiologically isolated syndrome refers to findings on MRIs of the brain and spinal cord that look like MS in someone without classic symptoms of MS.