Central Pontine Myelinolysis

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What is central pontine myelinolysis?

Central pontine myelinolysis (CPM), also known as osmotic demyelination syndrome, is a neurological disorder that most frequently occurs after too rapid medical correction of sodium deficiency (hyponatremia). The rapid rise in sodium concentration also involves the movement of small molecules and pulls water from brain cells that leads to the destruction of myelin, a substance that surrounds and protects nerve fibers. Nerve cells (neurons) also can be damaged.

Certain areas of the brain are particularly susceptible to myelinolysis, especially the part of the brain stem called the pons, which relays signals involving hearing, taste, movement, and other functions. Some individuals will also have damage in other areas of the brain, which is called extrapontine myelinolysis. Symptoms, some of which appear two to three days after hyponatremia, or over the next one to two weeks, include:

  • Depressed level of awareness
  • Difficulty speaking
  • Difficulty swallowing (dysphagia)
  • Impaired thinking
  • Weakness or paralysis in the arms and legs
  • Stiffness
  • Impaired sensation
  • Difficulty with coordination

Severe myelinolysis can lead to coma, “locked-in” syndrome (which is the complete paralysis of all of the voluntary muscles in the body except for those that control the eyes), and death. 

Anyone can develop hyponatremia and is at risk for myelinolysis; some individuals who are particularly vulnerable are those with chronic alcoholism or have had a liver transplant or liver or kidney disease. Although many affected people improve over weeks to months, some have permanent disability. Some also develop new symptoms later, including behavioral or intellectual impairment or movement disorders like parkinsonism or tremor.

Learn About Clinical Trials
Clinical trials are studies that allow us to learn more about disorders and improve care. They can help connect patients with new and upcoming treatment options.

How can I or my loved one help improve care for people with central pontine myelinolysis?

Consider participating in a clinical trial so clinicians and scientists can learn more about central pontine myelinolysis. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with myelinolysis at Clinicaltrials.gov, a database of current and past clinical studies and research results.

Where can I find more information about central pontine myelinolysis?

Information may be available from the following resources:



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