Multiple Sclerosis

Multiple Sclerosis

Signs and Symptoms
Diagnosis
Treatment

Signs and Symptoms

Multiple sclerosis (MS) damages the outer covering of nerve cells, called myelin, a fatty tissue that protects nerve cells in the same way that insulation protects electrical wiring in a house. Myelin helps nerve fibers conduct electrical impulses to and from the brain. Scar tissue, called sclerosis, accumulates when multiple areas of myelin are damaged. These damaged areas are known as plaques or lesions. Sometimes the nerve fiber itself is damaged and dies.

The exact cause of MS is not known, but factors such as disease, poisons and drug or alcohol abuse can damage the myelin sheath in children and adults. Heredity may contribute to the development of MS. About 5 percent of patients have a sister or brother who has the disease and about 15 percent have a close relative with MS.

When MS damages the protective myelin sheath of nerve cells, the sheath sometimes repairs itself and nerves work correctly again. In other cases, the myelin is so damaged that the underlying nerve can't be repaired and dies.

The symptoms of multiple sclerosis (MS) depend on which particular pathway of nerve fiber is damaged. Tingling, numbness, sensations of tightness or weakness may result when myelin in the spinal cord is damaged. If nerve fibers to the bladder are affected, urinary incontinence may occur. Likewise, damage to the cerebellum portion of the brain may result in imbalance or a lack of coordination. MS patients can have a wide range of symptoms, depending on where the damage occurs in the central nervous system.

Because MS can cause a wide variety of symptoms in different people, doctors frequently struggle to diagnose the disease. However, common symptoms of MS include changes in sensation or sensory symptoms such as tingling and numbness, and changes in muscle function or motor symptoms such as difficulty walking, stiffness or tremors. Some common symptoms are:

• Clumsiness or weakness
• Difficulty walking or maintaining balance
• Dizziness or vertigo
• Eye problems such as double vision or uncontrolled eye movements
• Fatigue
• Muscle spasms
• Problems with bladder or bowel control
• Stiffness
• Tremors
• Tingling or numbness
• Depression or emotional changes
• Mild intellectual change such as memory problems
• Sexual problems such as difficulty reaching orgasm, lack of vaginal sensation or erectile dysfunction

Symptoms usually appear in people between 20 and 40 years of age.

Reviewed by health care specialists at UCSF Medical Center.
Last updated December 12, 2007