Multiple sclerosis

In multiple sclerosis, the immune system attacks the protective sheath (myelin) that covers nerve fibers, resulting in impaired communication between the brain and body. Eventually, the disease can lead to permanent damage or degeneration of nerve fibers.

Signs and symptoms of multiple sclerosis vary from patient to patient and depend on the location and severity of nerve fiber damage in the central nervous system. In severe cases of multiple sclerosis, a person may lose the ability to walk independently or get around at all. Some patients, depending on the type of multiple sclerosis, may experience long periods of remission without new symptoms.

There is no cure for multiple sclerosis. However, there are treatments, so-called disease-modifying therapies, which help to change the course of the disease and manage symptoms.

Symptoms

The signs and symptoms of multiple sclerosis, as well as the course of the disease, can vary greatly from person to person, depending on the location of the affected nerve fibers.

Common symptoms include:

Numbness or weakness in one or more limbs, usually on one side of the body;
Tingling;
Electric shock sensations that occur with certain neck movements, especially when the neck is tilted forward (Lhermitte's sign);
Lack of coordination;
Unsteady gait or inability to walk;
Partial or complete loss of vision, usually in one eye, which is often accompanied by pain with eye movement;
Double vision;
Blurred vision;
Dizziness;
Problems with sexual activity, bowel and bladder function;
Fatigue;
Slurred speech;
Cognitive problems;
Mood disorders.

When should I see a doctor?

See your doctor if you experience any of the above symptoms for unknown reasons.

Course of the disease

In most cases, multiple sclerosis is characterized by a relapsing-remitting course of the disease. Patients experience periods of new symptoms, exacerbations or relapses that develop over several days or weeks, after which the condition usually partially or completely improves. These relapses are followed by quiet periods of remission of the disease, which may last for months or years.

A slight increase in body temperature may temporarily worsen the signs and symptoms of multiple sclerosis. This is not a true relapse of the disease, but a pseudo relapse.

Worsening symptoms usually include problems with mobility and gait. The rate of disease progression in people with secondary progressive multiple sclerosis varies greatly.

In some people with multiple sclerosis, signs and symptoms appear gradually and steadily without relapses, which is called primary progressive multiple sclerosis.

Causes of the disease

The cause of multiple sclerosis is unknown. It is considered an immune-mediated disease in which the body's immune system attacks its own tissues. In multiple sclerosis, disruption of the immune system destroys the fatty substance (myelin) that coats and protects nerve fibers in the brain and spinal cord.

Myelin can be compared to the insulating coating of electrical wires. When the protective myelin is damaged and a nerve fiber is exposed, signals transmitted along it can be slowed or even blocked. It is still unclear why multiple sclerosis only develops in some people. Various genetic and environmental factors are probably responsible..

Risk Factors

The following factors may increase your risk of developing multiple sclerosis:

Age. Multiple sclerosis can develop at any age, but the disease usually begins between the ages of 20 and 40. However, the disease occurs in both young and old people.
Gender. The incidence of relapsing-remitting multiple sclerosis is 2-3 times higher in women than in men.
Family history. If one of your parents or siblings has had multiple sclerosis, you have an increased risk of developing the disease.
Certain infections. Many viruses are linked to multiple sclerosis, including the Epstein-Barr virus, which causes infectious mononucleosis.
Race. White people, especially those of Northern European descent, are at the highest risk of developing multiple sclerosis.
Climate. Multiple sclerosis is much more common in countries with temperate climates. These include Canada, North America, New Zealand, Southeastern Australia, and Europe.
Vitamin D. Low vitamin D levels and lack of sunlight exposure are associated with an increased risk of developing multiple sclerosis.
Genes. A gene on chromosome 6p21 has been found to be associated with multiple sclerosis.
Obesity. A link between obesity and multiple sclerosis has been found in women.
Certain autoimmune diseases. People with autoimmune diseases such as thyroid disease, pernicious anemia, psoriasis, type 1 diabetes, or inflammatory bowel disease are at relatively high risk of developing multiple sclerosis.
Smoking. Smokers who have initial symptoms suggestive of multiple sclerosis are more likely than nonsmokers to have symptoms characteristic of relapsing-remitting multiple sclerosis.

Complications

People with multiple sclerosis may also develop:

Muscle stiffness or spasm;
Severe weakness or paralysis, usually in the legs;
Problems with bladder, bowel, or sexual function;
Cognitive problems, such as forgetfulness or difficulty finding words;
Mood problems such as depression, anxiety, or mood swings;
Seizures, although very rare.