Multiple sclerosis

Overview

Multiple sclerosis (MS) is a condition which can affect the brain and/or spinal cord, causing a wide range of potential symptoms, including problems with vision, arm or leg movement, sensation or balance.
It’s a lifelong condition that can sometimes cause serious disability, although it can occasionally be mild. In many cases, it’s possible to treat symptoms. Average life expectancy is slightly reduced for people with MS.
It’s estimated that there are more than 100,000 people diagnosed with MS in the UK.
It’s most commonly diagnosed in people in their 20s and 30s, although it can develop at any age. It’s about two to three times more common in women than men.
Multiple sclerosis (MS) is a potentially disabling disease of the brain and spinal cord (central nervous system).

In MS, the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems between your brain and the rest of your body. Eventually, the disease can cause the nerves themselves to deteriorate or become permanently damaged.
Signs and symptoms of MS vary widely and depend on the amount of nerve damage and which nerves are affected. Some people with severe MS may lose the ability to walk independently or at all, while others may experience long periods of remission without any new symptoms.
There’s no cure for multiple sclerosis. However, treatments can help speed recovery from attacks, modify the course of the disease and manage symptoms.

Symptoms

Symptoms of multiple sclerosis

Multiple sclerosis signs and symptoms may differ greatly from person to person and over the course of the disease depending on the location of affected nerve fibers. They may include:

Numbness or weakness in one or more limbs that typically occurs on one side of your body at a time, or the legs and trunk
Partial or complete loss of vision, usually in one eye at a time, often with pain during eye movement
Prolonged double vision
Tingling or pain in parts of your body
Electric-shock sensations that occur with certain neck movements, especially bending the neck forward (Lhermitte sign)
Tremor, lack of coordination or unsteady gait
Slurred speech
Fatigue
Dizziness
Problems with bowel and bladder function
When to see a doctor
See a doctor if you experience any of the above symptoms for unknown reasons.
Disease course
Most people with MS have a relapsing-remitting disease course. 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.
Small increases in body temperature can temporarily worsen signs and symptoms of MS, but these aren’t considered disease relapses.
About 60 to 70 percent of people with relapsing-remitting MS eventually develop a steady progression of symptoms, with or without periods of remission, known as secondary-progressive MS.
The worsening of symptoms usually includes problems with mobility and gait. The rate of disease progression varies greatly among people with secondary-progressive MS.
Some people with MS experience a gradual onset and steady progression of signs and symptoms without any relapses. This is known as primary-progressive MS.

Types of MS

MS starts in one of two general ways: with individual relapses (attacks or exacerbations) or with gradual progression.
Relapsing-remitting MS
More than 8 out of every 10 people with MS are diagnosed with the “relapsing remitting” type.
Someone with relapsing remitting MS will have episodes of new or worsening symptoms, known as “relapses”. These typically worsen over a few days, last for days to weeks to months, then slowly improve over a similar time period.
Relapses often occur without warning, but are sometimes associated with a period of illness or stress.
The symptoms of a relapse may disappear altogether, with or without treatment, although some symptoms often persist, with repeated attacks happening over several years.
Periods between attacks are known as periods of “remission”. These can last for years at a time.

After many years (usually decades), many, but not all people, with relapsing remitting MS go on to develop secondary progressive MS. In this type of MS, symptoms gradually worsen over time without obvious attacks. Some people continue to have infrequent relapses during this stage.
Around half of people with relapsing remitting MS will develop secondary progressive MS within 15-20 years, and the risk of this happening increases the longer you have the condition.
Primary progressive MS
Just over 1 in 10 people with the condition start their MS with a gradual worsening of symptoms.
In primary progressive MS, symptoms gradually worsen and accumulate over several years, and there are no periods of remission, though people often have periods where their condition appears to stabilise.
Causes
The cause of multiple sclerosis is unknown. It’s considered an autoimmune disease in which the body’s immune system attacks its own tissues. In the case of MS, this immune system malfunction destroys myelin (the fatty substance that coats and protects nerve fibers in the brain and spinal cord).
Myelin can be compared to the insulation coating on electrical wires. When the protective myelin is damaged and nerve fiber is exposed, the messages that travel along that nerve may be slowed or blocked. The nerve may also become damaged itself.
It isn’t clear why MS develops in some people and not others. A combination of genetics and environmental factors appears to be responsible.
Risk factors
These factors may increase your risk of developing multiple sclerosis:
Age. MS can occur at any age, but most commonly affects people between the ages of 15 and 60.
Sex. Women are about twice as likely as men are to develop MS.
Family history. If one of your parents or siblings has had MS, you are at higher risk of developing the disease.
Certain infections. A variety of viruses have been linked to MS, including Epstein-Barr, the virus that causes infectious mononucleosis.
Race. White people, particularly those of Northern European descent, are at highest risk of developing MS. People of Asian, African or Native American descent have the lowest risk.
Climate. MS is far more common in countries with temperate climates, including Canada, the northern United States, New Zealand, southeastern Australia and Europe.
Certain autoimmune diseases. You have a slightly higher risk of developing MS if you have thyroid disease, type 1 diabetes or inflammatory bowel disease.
Smoking. Smokers who experience an initial event of symptoms that may signal MS are more likely than nonsmokers to develop a second event that confirms relapsing-remitting MS.
Complications
People with multiple sclerosis also may develop:
Muscle stiffness or spasms
Paralysis, typically in the legs
Problems with bladder, bowel or sexual function
Mental changes, such as forgetfulness or mood swings
Depression
Epilepsy