A demyelinating disease is any condition that causes damage to the protective covering that surrounds nerve fibers. This covering is called the myelin sheath. In the central nervous system, the myelin sheath protects nerves in the brain, spinal cord and nerves leading to the eyes, known as optic nerves.

When the myelin sheath is damaged, nerve impulses slow or even stop. This can cause neurological symptoms such as trouble walking or seeing, or changes in bowl and bladder function.

Multiple sclerosis

Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system. In this disease, the immune system attacks the myelin sheath or the cells that produce and maintain it.

The attack causes swelling, also known as inflammation, and injury to the myelin sheath. Ultimately, the nerve fibers the myelin sheath surrounds are damaged. The process can result in areas of scarring, known as sclerosis.

Other causes

Other types of demyelinating disease and their causes include:

• Optic neuritis — inflammation of the optic nerve in one or both eyes.
• Neuromyelitis optica spectrum disorder (NMOSD) — inflammation and demyelination of the central nervous system, especially of the optic nerve and spinal cord.
• Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) — inflammatory disease of the central nervous system that affects the optic nerve and spinal cord.
• Transverse myelitis — inflammation of the spinal cord.
• Acute disseminated encephalomyelitis — inflammation of the brain and spinal cord.

MS and other demyelinating diseases most commonly cause:

• Vision loss.
• Muscle weakness.
• Muscle stiffness and spasms.
• Loss of coordination.
• Changes in feeling, also known as sensation.
• Trouble walking.
• Changes in bladder and bowel function.

Treatment

There is no cure for demyelinating diseases. But disease-modifying therapies can help slow the progression of the disease in some people. Disease-modifying therapies can be used together with medicines that treat symptoms. Symptoms and how quickly the demyelinating disease gets worse varies from person to person. Getting diagnosed early and talking to a healthcare professional about treatment options is important. The goal of treatment is to:

• Minimize the effects of the attacks.
• Modify the course of the disease.
• Manage the symptoms.

A variety of therapies are recommended, depending on the disease being treated. These include medicines to improve walking, spasms, bladder dysfunction and other symptoms. Physical therapy, occupational therapy and cognitive behavioral therapy also can help manage symptoms. Talk with your healthcare professional about treatment options for your specific disease.