Multiple Sclerosis: Types and Symptoms

Multiple sclerosis (MS) is an autoimmune disease in which the body’s immune system mistakenly attacks its own nerve cells, causing disruption of nerve signals between the brain and the muscles, skin, eyes, and other areas. As a result, strength, movement, coordination, sensation, vision, and even the ability to think clearly can be affected.

MS affects about 1 million people around the world. Most cases occur in adults between 20 and 50 years of age, and the disease is more common in women and Caucasians. Its cause is not yet known, but genetic, environmental, and viral factors are being investigated.

The severity of disease depends on which nerves are affected and how fast it progresses. Some cases are mild, but others can be debilitating and even life–threatening. In some patients, the visual nerves are primarily affected, resulting mostly in visual disturbances. In other patients, the muscular nerves are mostly affected, resulting in difficulty walking or performing daily tasks. In still others, the sensory nerves are primarily affected, resulting in numbness or tingling. Many patients have combinations of all of these symptoms.

Types of MS

• Relapsing remitting: This is the most common type, and is characterized by symptom flare–ups that last several weeks or months, followed by remission.
• Primary progressive: This pattern of MS is most common in older patients. It is characterized by gradual deterioration of function without remission.
• Secondary progressive: This pattern initially begins as relapsing remitting disease, but then begins to follow a course of gradual deterioration without remission.

Symptoms

Symptoms vary widely and depend on the location of damaged nerve fibers. In some cases, the disease is asymptomatic. In others, patients are severely affected and follow a rapid downhill course.

• Sensory symptoms: Numbness, tingling, or pain in one or more limbs
• Motor (muscular) symptoms: Weakness, stiffness, muscle spasm, tremor, lack of coordination, unsteadiness or difficulty walking, or paralysis
• Visual disturbances: Partial or complete loss of vision (usually one eye at a time), eye pain, double vision, or blurring of vision
• Mental changes: Poor concentration, forgetfulness
• Electric–shock sensations down the back may occur during head movement
• Slurred speech
• Dizziness
• Fatigue
• Loss of bladder or bowel control