Symptoms

Signs and Symptoms

Symptoms of MS vary depending on the location of your affected nerve fibers. Signs and symptoms may include:

Numbness, weakness or paralysis in one or more limbs

Brief pain, tingling or electric shock sensations

Tremor, lack of coordination or unsteady gait

Impaired vision with pain during movement in one eye

Disordered eye movements, causing double vision or moving field of vision

Fatigue

Dizziness

As the disease gradually worsens, muscle spasms, slurred speech, vision loss, problems with bladder, bowel or sexual function and paralysis may develop. Occasionally, mental changes such as forgetfulness or confusion occur.

Causes

Your central nervous system contains millions of nerve cells joined by nerve fibers. Electrical impulses originate in nerve cells and travel along the nerve fibers to and from your brain. Myelin, a fatty substance, coats and protects the fibers, similar to the way insulation shields electrical wires.

Strong evidence suggests that MS results from an autoimmune process. Before symptoms of MS develop, immune cells flood into the central nervous system. These cells normally circulate into and out of the brain, checking for viruses and helping fight disease. But doctors believe that with MS, the immune cells that have been primed outside the brain by a protein that mimics myelin mistakenly destroy the cells that produce the myelin sheath.

Myelin becomes inflamed, swollen and detached from the fibers. Eventually, the detached myelin is destroyed. Firm or hardened (sclerosed) patches of scar tissue form over the fibers. When nerve impulses reach a damaged area, some impulses are blocked or delayed from traveling to or from your brain. Ultimately, this process leads to degeneration of the nerves themselves, which likely accounts for the permanent disabilities that develop in MS.

No one knows what triggers this process. Some researchers suspect a virus in either immune cells or in sheath-producing cells.

Music by the Beatles, "Magical Mystery Tour"