When you think of myelin, think of the insulation around an electrical wire. Myelin is essentially an insulating layer of lipids and proteins that covers many of your nerves. If that coating becomes damaged or wears away, it causes problems with your nerves’ ability to send and receive electrical messages normally.

That reduces your nerves’ ability to communicate and function. That can make it harder for you to move around, perform ordinary tasks, and even see what you’re doing, in some cases. Fatigue is also common.

Inflammation is one common cause of damage to myelin, but other things can cause demyelination, including:

Discover what disorders that can develop when your nerves experience damage to the myelin sheath around them.

There are two main categories of demyelinating disease: demyelinating disease of the central nervous system (CNS) and demyelinating disease of the peripheral nervous system (PNS).

CNS demyelinating disease

This category of disease includes conditions such as:

  • Multiple sclerosis (MS): MS is the most common type of demyelinating disease of the central nervous system, and affects about 1 million people in the United States.
  • Optic neuritis: Optic neuritis is inflammation of the optic nerves. It affects about half of all people with MS.
  • Transverse myelitis: Transverse myelitis is inflammation of both sides of a section of the spinal cord. About 1,400 new cases are diagnosed each year in the United States, with about 33,000 people experiencing symptoms or disability as a result of this condition.
  • Acute disseminated encephalomyelitis (ADEM): ADEM is a severe bout of inflammation in which swelling damages the myelin on cells in the brain, spinal cord, and sometimes the optic nerves.
  • Neuromyelitis optica (NMO): Neuromyelitis optica affects the eyes and the spinal cord first, and eventually also may affect the brain. Also known as Devic’s disease, it’s a rare disease that affects only about 4,000 people in the United States.
  • Adrenoleukodystrophy: There are three different kinds of adrenoleukodystrophy: childhood cerebral ALD, adrenomyelopathy, and Addison’s disease. It affects about 1 in every 20,000 to 50,000 people.

PNS demyelinating disease

This category includes conditions such as:

  • Chronic inflammatory demyelinating polyneuropathy: Also known as chronic relapsing polyneuropathy, CIDP causes progressive muscle weakness and affects roughly 5 to 7 out of every 100,000 people.
  • Guillain Barré-syndrome (GBS): GBS is an autoimmune disorder in which your immune system attacks the cells of your peripheral nervous system. It’s considered rare, as it affects only about 1 in 100,000 people in the United States.

In many of these disorders, the exact cause isn’t known. Scientists are learning more about them, as research is ongoing, but here’s what they know now:

ConditionCause
Multiple sclerosisThe exact cause is still unknown, although experts believe that genetic and environmental factors may be at work. Women are two to three times more likely to develop MS.
Optic neuritisYou are at increased risk for developing optic neuritis if you already have MS or NMO. Infections and other diseases sometimes give rise to inflammation of the optic nerve, too. But the exact cause is not yet completely understood.
Transverse myelitisExperts speculate that it could be immune-mediated, or it could be the result of an infection. It sometimes develops as an early symptom of MS. But it’s estimated that in 16-60 percent of cases, the exact cause isn’t known.
Acute disseminated encephalomyelitisAgain, while scientists still hope to pinpoint an exact cause, the general thinking is that a viral or bacterial infection may cause the inflammation that’s the hallmark of this condition. It tends to affect more children than adults.
Neuromyelitis opticaIt often strikes in childhood, but it can also affect adults and is more common in women than in men. In fact, more than 80 percent of diagnosed cases of NMO occur in women.
AdrenoleukodystrophyThis disorder affects the nervous system and the adrenal glands. It’s an X-linked recessive inherited condition, which means that it’s caused by a mutation on a gene on the X chromosome. So it tends to affect more men than women.
Chronic inflammatory demyelinating polyneuropathySome experts suspect that this may be a chronic version of a common form of Guillain-Barré syndrome (GBS) known as acute inflammatory demyelinating polyneuropathy (AIDP), which appears to be an autoimmune disorder.
Guillain-Barré syndromeResearch suggests that there are four subtypes of GBS, and the causes can vary. Infection may be one notable culprit. For example, a recent infection with Campylobacter jejuni bacteria seems to cause GBS in about a quarter of people who are diagnosed.

Sometimes the symptoms will be similar to various conditions that cause damage to the myelin of your nerve cells. Here’s more detailed information about symptoms you might expect from these disorders.

Multiple sclerosis

MS causes a wide variety of symptoms that can range from mild to severe. Some people experience:

Optic neuritis

The most common symptoms include vision loss in one eye, pain around your eye that’s exacerbated by eye movement, and difficulty distinguishing between colors.

Transverse myelitis

Symptoms of transverse myelitis can include:

Acute disseminated encephalomyelitis

You may develop a number of symptoms, including:

Neuromyelitis optica

Some people experience a single long-lasting attack, while others have a relapsing form of NMO.

Symptoms of NMO include:

  • vision loss and eye pain in one or both eyes
  • numbness, weakness, or even paralysis in arms or legs
  • loss of bladder and bowel control

Adrenoleukodystrophy

Symptoms can vary, depending on what type of ALD you have.

Someone with childhood cerebral ALD may develop:

Someone with Addison’s disease may:

Chronic inflammatory demyelinating polyneuropathy

With this condition, you may develop:

Guillain-Barré syndrome

GBS causes symptoms that can range from relatively mild weakness to paralysis. Some people might not even be able to breathe on their own without assistance. As many as 20 percent of people are left with significant disability.

Once a diagnosis is made, your doctor can begin discussing the most appropriate treatment for you.

Multiple sclerosis

There are a number of different FDA-approved preventive treatments for reducing the frequency and severity of MS symptoms, including:

Steroids are also prescribed for flare-ups or exacerbations. Recent research also suggests that it may be possible to repair the myelin if people have enough surviving oligodendrocyte cells, which wrap around the nerve cells, to begin making new myelin.

Optic neuritis

Sometimes optic neuritis symptoms will improve on their own, but your doctor may prescribe steroids to address the inflammation.

Transverse myelitis

Treatment may be given to address symptoms and reduce inflammation, and to address any infections that might be present. Possible treatments include:

  • intravenous corticosteroid therapy
  • plasma exchange therapy
  • intravenous immunoglobin (IVIG)
  • antivirals for any infections in the spinal cord
  • pain medications to address both muscle and nerve pain

Neuromyelitis optica

Your doctor may prescribe corticosteroids or immunosuppressants to reduce symptoms. Another possible option is a process called plasmapheresis, which removes certain antibodies from your blood that may be contributing to the symptoms.

Acute disseminated encephalomyelitis

Intravenous steroids like methylprednisolone or oral steroids can help reduce the inflammation caused by ADEM. Plasmapheresis may also be an option with severe cases of this condition.

Adrenoleukodystrophy

One effective treatment for childhood ALD is hematopoietic stem cell transplant, which is a bone marrow transplant. People with Addison’s disease may experience some benefit from taking steroids. Some people may also take seizure medications or go to physical therapy to help with muscle spasms and weakness.

Chronic inflammatory demyelinating polyneuropathy

The most commonly used treatments include glucocorticoids, intravenous immunoglobulin (IVIg), and plasma exchange therapy to help modulate the immune system. Physiotherapy might help you build or maintain muscle strength and function, so you can be as mobile as possible.

Guillain-Barré syndrome

There’s no cure for GBS, but doctors may offer treatment such as high-dose immunoglobulin therapy (IVIg) or plasma exchange to ward off nerve damage. In the past, corticosteroid therapy was offered, but eventually research found it wasn’t effective.

Ongoing research, including research into stem cell therapies, may eventually bear fruit in the form of new effective treatments for a variety of disorders that affect the myelin covering of nerve cells.

In the meantime, communicating with your doctor about your symptoms, using strategies to help with your daily activities, and reaching out for support are good ways to manage your needs.