Progressive Multifocal Leukoencephalopathy Overview
What is progressive multifocal leukoencephalopathy?
Progressive multifocal leukoencephalopathy, or PML, is a rare disorder that results in damage to the myelin sheath. The myelin sheath covers and protects nerves in the brain. Myelin acts as an insulator that allows signals to travel normally along the nerves. When the myelin sheath is damaged, signals from the brain do not reach the rest of the body. Progressive multifocal leukoencephalopathy is caused by a virus, called the JC virus (JCV). JC virus is present in most people. It does not cause PML unless the immune system is weakened by other illnesses, such as AIDS, leukemia, or lymphoma. PML may also occur in those with organ transplants because they receive medications that weaken the immune system, in order to avoid organ rejection.
What are the symptoms of progressive multifocal leukoencephalopathy?
The symptoms of progressive multifocal leukoencephalopathy include headache, chronic headaches, loss of coordination, clumsiness, difficulty speaking, aphasia, memory loss, vision problems, and weakness of the legs and arms that gets worse.
How does the doctor treat progressive multifocal leukoencephalopathy?
Treatment for progressive multifocal leukoencephalopathy includes antiviral medications and avoiding medications that suppress the immune system. Treatment is directed at strengthening the immune system, so it can fight the viral infection.
- 2010 Apr;9(4):425-37. 
- Love S. Demyelinating diseases. J Clin Pathol. 2006 Nov;59(11):1151-9. Review. PubMed PMID: 
- Tan CS, Koralnik IJ. Progressive multifocal leukoencephalopathy and other disorders caused by JC virus: clinical features and pathogenesis. Lancet Neurol.