Progressive Multifocal Leukoencephalopathy (PML) is a rare disease that gets worse over time. It leads to damage of the brain cells.
PML is caused by an infection by a specific virus. Many people pick up this virus as a child, but do not get sick until later. The virus stays in the body and does not cause problems in most.
If the immune system becomes weak, the virus can begin to cause problems. The virus attacks the coating around the brain cells called myelin. Messages can't be passed between brain cells without myelin.
PML is most common in people who have problems with their immune system. These problems may be from:
Symptoms get worse over time and may include:
Your doctor will ask about your symptoms and medical history. A physical exam will be done.
An MRI scan will be needed to see any damage to the brain cells. This may help to rule out other causes.
To confirm diagnosis, your doctor may need:
There is no treatment for the infection or PML. Treatment is aimed at ways to improve the immune system to stop further damage. Options will depend on your specific needs, but examples include:
Damage to the cells cannot be fixed. This can cause severe disability.
AIDS Information, Education, Action, Awareness
NORD—National Organization for Rare Disorders
Canadian AIDS Society
CORD—Canadian Organization for Rare Disorders
NINDS progressive multifocal leukoencephalopathy information page. National Institute of Neurological Disorders and Stroke website. Available at https://www.ninds.nih.gov/Disorders/All-Disorders/Progressive-Multifocal-Leukoencephalopathy-Information-Page. Accessed April 4, 2018.
Progressive multifocal leukoencephalopathy. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T116949/Progressive-multifocal-leukoencephalopathy-PML. Updated December 1, 2017. Accessed April 4, 2018.
Progressive multifocal leukoencephalopathy (PML). AETC National Resource Center website. Available at: http://aidsetc.org/resource/progressive-multifocal-leukoencephalopathy-pml. Updated May 1, 2013. Accessed April 4, 2018.
Warnke C, Menge T, Hartung HP, et al. Natalizumab and progressive multifocal leukoencephalopathy: what are the causal factors and can it be avoided? Arch Neurol. 2010;67(8):923-930.
Last reviewed January 2018 by Rimas Lukas, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.