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The information contained on this page is provided as general health information and is not intended to substitute as medical advice and direction from your physician or health care provider. Please direct any questions related to your health care provider. In an emergency, call 9-1-1 or go to the nearest emergency center.


Progressive multifocal leukoencephalopathy

Definition

Progressive multifocal leukoencephalopathy (PML) is a rare infection that damages the material (myelin) that covers and protects nerves in the white matter of the brain.

Alternative Names

PML; John Cunningham virus; JCV

Causes

The John Cunningham virus, or JC virus (JCV) causes PML. By age 10, most people have been infected with this virus though it hardly ever causes symptoms. But, people with a weakened immune system are at risk of developing PML. Causes of a weakened immune system include:

  • HIV/AIDS (less common cause of PML now because of better management of HIV/AIDS).
  • Certain medicines that suppress the immune system. Such medicines may be used to prevent organ transplant rejection or to treat multiple sclerosis, rheumatoid arthritis and other autoimmune disorders, and related conditions.
  • Cancers, such as leukemia and Hodgkin lymphoma.

Symptoms

Symptoms may include any of the following:

  • Loss of coordination, clumsiness
  • Loss of language ability (aphasia)
  • Memory loss
  • Vision problems
  • Weakness of the legs and arms that gets worse
  • Personality changes

Exams and Tests

The health care provider will perform a physical exam and ask about symptoms.

Tests may include:

Treatment

In people with HIV/AIDS, treatment to strengthen the immune system can lead to recovery from the symptoms of PML. No other treatments have proved effective for PML.

Outlook (Prognosis)

PML is a life-threatening condition. Depending on how severe the infection is, up to one half of people diagnosed with PML die within the first few months.Talk to your provider about care decisions.

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Gray and white matter of the brainLeukoencephalopathy

References

Berger JR, Nath A. Cytomegalovirus, Epstein-Barr virus, and slow virus infections of the central nervous system. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 370.

Tan CS, Koralnik IJ. JC, BK, and other polyomaviruses: progressive multifocal leukoencephalopathy (PML). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 147.