Progressive multifocal leukoencephalopathy

Gray and white matter of the brain

The tissue called “gray matter” in the brain and spinal cord is also known as substantia grisea, and is made up of cell bodies. “White matter”, or substantia alba, is composed of nerve fibers.

Also known as: PML

Definition

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

Causes, incidence, and risk factors

The JC virus (JCV) causes PML. By age 10, most people have been infected with this virus, but it hardly ever causes symptoms.

Anyone with a weakened immune system, however, are at greater risk of developing PML. Causes of a weakened immune system include:

  • AIDS (less common now because of better AIDS treatments)
  • Certain medications used to treat multiple sclerosis, rheumatoid arthritis, and related conditions
  • Leukemia and lymphoma

Symptoms

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

Signs and tests

Tests may include:

Treatment

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

Expectations (prognosis)

PML is a life-threatening condition. Talk to your doctor about care decisions.

References

Boren EJ, Cheema GS, et al. The emergence of progressive multifocal leukoencephaloparhy (PML) in rheumatic diseases. J Autoimmun. 2008;30(1-2):90-98.

See also:

  • Disease

    Immunodeficiency disorders

    Antibodies

    Immunodeficiency disorders occur when the body’s immune response is reduced or absent. See also:

  • Special Topic

    White matter of the brain

    Brain

  • Test

    Visual field

    Eye

    The visual field refers to the total area in which objects can be seen in the side (peripheral) vision while you focus your eyes on a central point.

  • Symptoms

    Weakness

    Weakness is a reduction in the strength of one or more muscles.

  • Symptoms

    Speech impairment (adult)

    Brain

    Speech and language impairment may be any of several problems that make it difficult to communicate. See also:

  • Symptoms

    Headache

    Brain

    A headache is pain or discomfort in the head, scalp, or neck. Serious causes of headaches are very rare. Most people with headaches can feel much better by making lifestyle changes, learning ways to relax, and sometimes by taking medications. See also:

  • Symptoms

    Movement - uncoordinated

    Muscular atrophy

    Uncoordinated movement is muscle control problem or an inability to finely coordinate movements, which results in a jerky, unsteady, to-and-fro motion of the middle of the body (trunk) and (walking style). The condition is called ataxia.

Review date:
February 6, 2010
Reviewed by:
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Luc Jasmin, MD, PhD, Department of Neurosurgery at Cedars-Sinai Medical Center, Los Angeles, CA, and Department of Anatomy at UCSF, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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