Demyelinating Disease

What is a demyelinating disease?

A demyelinating disease is a condition that causes a damage to the myelin in your brain, spinal cord and nerves. Myelin is a protective cover (sheath) around the body section (axon) of nerve cells (neurons) in your central and peripheral nervous system. Myelin strengthens, protects and insulates your nerve cells and allows electrical impulses to travel between cells.

If you have a demyelinating disease, your immune system mistakenly attacks the myelin sheath or the cells that make up your myelin. This changes the way your nerves communicate and function, which causes symptoms.

What are the types of demyelinating diseases?

Common demyelinating diseases that affect your central nervous system (brain and spinal cord) include:

• Multiple sclerosis (MS).
• Neuromyelitis optica spectrum disorder (NMOSD).
• Transverse myelitis (TM).
• Acute disseminated encephalomyelitis (ADEM).
• Progressive multifocal leukoencephalopathy (PML).
• Central pontine myelinolysis (osmotic demyelination syndrome).

Common demyelinating diseases that affect your peripheral nervous system (nerves outside of your brain and spinal cord) include:

• Guillain-Barré syndrome (GBS).
• Charcot-Marie-Tooth disease (CMT).
• Chronic inflammatory demyelinating polyneuropathy (CIDP).

Is demyelinating disease always MS?

No, there are several conditions that are classified as demyelinating diseases. MS is the one most common in North America.

How common are demyelinating diseases?

Multiple sclerosis is one of the most common demyelinating diseases. A study in 2019 estimated that there were nearly 1 million people in the United States living with MS.

What are the symptoms of a demyelinating disease?

Signs and symptoms of demyelinating diseases vary based on the type. Common symptoms of a central nervous system demyelinating disease may include:

• Vision changes, including blurry vision, impaired color vision, pain with eye movement or double vision.
• Tingling or numbness in various parts of your body.
• MS hug or a squeezing sensation around your chest or abdomen.
• Fatigue.
• Bladder or bowel problems, including difficulty (or hesitancy) when trying to pee or a feeling of urgency (as in, when you have to go, you have to go).
• Electrical tingling or shocks down your back, arms or legs when you bend your neck forward.
• Difficulty walking.
• Muscle weakness or stiffness.

You might experience symptoms that affect only one part of your body or many at the same time. Symptoms can fluctuate in severity. This means that they can get worse (feel more intense) before improving for a period of time.

What causes a demyelinating disease?

The destruction of myelin and myelin-forming cells causes demyelinating diseases. Damage to your myelin and cells happens when your immune system mistakenly attacks healthy myelin. Your immune system protects your body from things that can make you sick, like bacteria and viruses. Sometimes, your immune system doesn’t get the correct instructions and it confuses your myelin cells for cells of something that can harm your body. When this happens, it causes inflammation, which leads to symptoms of demyelinating diseases.

A demyelinating disease can happen due to multiple factors, which can include:

• A viral or bacterial infection.
• Genetic predisposition (changes in your DNA) that predispose someone to an autoimmune disorder.
• Other medical conditions such as vitamin deficiencies.

Some causes are unknown. Research is ongoing to learn more about demyelinating diseases.

How is a demyelinating disease diagnosed?

A healthcare provider will review your symptoms during a physical exam. They’ll also take a complete medical history to learn more about you. If they suspect a demyelinating disease, they might refer you to see a neurologist. A neurologist is a doctor who specializes in conditions that affect your nervous system.

The neurologist will perform a neurological exam and testing. There isn’t one test to diagnose demyelination. Your provider may use one or several of the following tests to rule out possible conditions with similar symptoms to lead to your diagnosis:

• MRI (magnetic resonance imaging) scan.
• Lumbar puncture (spinal tap).
• Optical coherence tomography (OCT).
• Electromyography (EMG).
• Blood tests.
• Evoked potentials test.

How does an MRI detect a demyelinating disease?

An MRI is an imaging test that can give your healthcare provider a better picture of what’s going on inside your body. It uses magnets and radio waves to take a picture of your brain and spinal cord. An MRI will show areas of damage (lesions) in your brain and spinal cord if you have a demyelinating disease.

How is a demyelinating disease treated?

Treatment for a demyelinating disease varies based on what condition you have. Your healthcare provider will work closely with you to manage symptoms and, in some cases, change the course or progression of the condition in your body. Treatment could include:

• Medications.
• Physical and/or occupational therapy.

Your healthcare provider will evaluate your symptoms and the type of treatment plan best for your situation. Before you begin treatment, ask about the side effects and what to expect. If you notice new or worsening symptoms after starting treatment, let your healthcare provider know. Treatment is usually most effective when you start it early.

What’s the outlook or prognosis for a demyelinating disease?

Your outlook varies based on the type of demyelinating disease that caused your symptoms. These conditions affect many aspects of your life, like how you think, move and feel. You might have trouble walking or doing your daily routine, for example. Many people need assistance at home so they can live in a safe environment. Some people may have very mild symptoms without any long-term effects, while other people’s symptoms are severe and significantly impact day-to-day life. Each situation is different. Your healthcare provider can help you manage your symptoms throughout your life, as there isn’t a cure.

What is the life expectancy for a demyelinating disease?

Demyelinating diseases can affect your life expectancy, but many don’t have a direct impact on how long you’ll live. On average, people with a demyelinating disease may have a slightly shorter life expectancy (a few years shorter) than people who don’t have this condition. Your life expectancy varies based on how much damage your nerve cells receive. This is different for each person. Your healthcare provider can give you the best answer to this question based on how the condition affects you.

When should I see a healthcare provider?

Contact a healthcare provider if you experience symptoms of demyelinating disease like:

• Vision changes.
• Tingling or numbness.
• Fatigue.
• Bladder or bowel problems.
• Trouble walking.
• Stiff or weak muscles.

What questions should I ask my healthcare provider?

• What type of demyelinating disease do I have?
• Will this condition get worse (progress)?
• What type of treatment do you recommend?
• Are there side effects of treatment?
• What is my outlook (prognosis)?