Progressive Multifocal Leukoencephalopathy
PML is a rare progressive disease of the nervous system. It is caused by a viral infection of the cells that produce myelin.
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PML is caused by a specific papovavirus, known as JC virus. Most people get this infection in childhood and it produces no illness. It reactivates later in life in people who have suppressed immune systems.
The virus damages myelin, the material that wraps around nerves. This impairs nerve function.
PML is most common in people with supressed immune systems. Supressed immune systems may be the result of:
- Organ transplant
- Chronic steroid therapy
- Rare inherited immunodeficiencies
Certain medications, such as
natalizumab, a medication used to treat
Symptoms progress over weeks and may include:
- Vision problems
- Speech pronunciation problems
- Coordination loss
- Memory loss
- Weakness in limbs
- Behavioral changes
—a loss of language capability
- Sensory loss
Your doctor will ask about your symptoms and medical history. A physical exam will be done. Tests may include:
Treatment focuses on strategies to improve the immune system. If you have HIV, your doctor will most likely prescribe antiretroviral medications to treat this condition. If PML has resulted from the drug natalizumab, your doctor will have you stop taking this drug and may recommend a
to remove the drug from your blood system.
There are no current guidelines to prevent exposure to the JC virus. If you have a suppressed immune system, get treatment to minimize your risk.
AIDS Information, Education, Action, Awareness
National Organization for Rare Disorders
Canadian AIDS Society
Canadian Organization for Rare Disorders
AETC National Resource Center. Progressive multifocal leukoencephalopathy. AETC National Resource Center website. Available at:
. Accessed July 11, 2013.
National Institute of Neurological Disorders and Stroke. Progressive multifocal leukoencephalopathy information page. National Institute of Neurological Disorders and Stroke website. Available at
. Updated September 27, 2011. Accessed July 11, 2013.
Progressive multifocal leukoencephalopathy. EBSCO DynaMed website. Available at:
. Updated May 21, 2013. Accessed July 11, 2013.
Warnke C, Menge T, Hartung HP, et al. Natalizumab and progressive multifocal leukoencephalopathy: what are the causal factors and can it be avoided?