The myelin sheath is a layer of insulation made up of fatty substances and protein that surrounds nerve cell fibers. The myelin sheath allows the nerve cells to transit impulses through the body quickly and efficiently. Demyelinating diseases are those that cause damage to the myelin sheath. When the myelin sheath is damaged, nerve impulses are slowed down and disrupted, which can cause a multitude of problems in the body.
Optic Neuritis
Optic neuritis is characterized by inflammation of the optic nerve, the nerve that connects the eye to the brain and allows for sight. Chronic inflammation of the optic nerve damages the myelin sheath that surrounds it. This inflammation may be caused by autoimmune diseases, infections, drug use and vitamin deficiency. Symptoms of optic neuritis include loss of vision in the affected eye, pupil changes, loss of color vision and pain during eye movement. Treatment focuses on determining the cause of optic neuritis and treating the underlying condition. Corticosteroids may be given intravenously if the inflammation is severe, but are used carefully because they can have serious side effects, according to Medline Plus.
Transverse Myelitis
Transverse myelitis is characterized by inflammation of the myelin sheath that surrounds the spinal cord. The inflammation causes immediate damage to the myelin sheath and symptoms usually appear in a few hours, according to the Mayo Clinic. Common symptoms include pain, abnormal sensations such as numbness and tingling, weakness of the arms and legs, and bladder and bowel problems. Other possible symptoms include muscle spasms, headache and fever. Transverse myelitis can develop as a result of an autoimmune disorder, or may be the result of a viral or bacterial infection that affects the spinal cord, such as herpes simplex. Initial treatment is aimed at the reduction of inflammation and the resulting symptoms, and includes intravenous steroids, pain medications and plasma exchange therapy. Long-term treatment consists of physical therapy and occupational therapy.
Chronic Inflammatory Demyelinating Polyneuropathy
Chronic inflammatory demyelinating polyneuropathy is characterized by inflammation and damage to the myelin sheath that surrounds the peripheral nerves, which are any nerves that are not located in the brain or spinal cord. Symptoms of the disease include tingling and numbness that usually begin in the toes and fingers, progressive weakness of the arms and legs, loss of reflexes, fatigue and abnormal sensations. Anti-inflammatory drugs and immunosuppressant drugs are often used in the treatment of chronic inflammatory demyelinating polyneuropathy. Plasma exchange therapy and intravenous immunoglobulin therapy are two blood treatments that have also been proven effective, according to the National Institute of Neurological Disorders and Stroke. Additionally, physical therapy may be incorporated into treatment to maintain muscle strength and function.
