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.
The JC virus (JCV) causes PML. By age 10, most people have been infected with this virus. But it hardly ever causes symptoms. However, persons with a weakened immune system are at risk of developing PML. Causes of a weakened immune system include:
Tests may include:
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.
PML is a life-threatening condition. Talk to your doctor about care decisions.
Reviewed By: Joseph V. Campellone, M.D., Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.