What is Progressive Multifocal Leukoencephalopathy?

Progressive multifocal leukoencephalopathy is a very uncommon disease that afflicts people who have AIDS or other conditions that weaken their immune systems. The disease is triggered by the JC virus, a widespread, weak pathogen that is found in as much 85 percent of the population. A person who suffers from progressive multifocal leukoencephalopathy is likely to experience a number of neurological problems, including coordination issues, speech difficulties, and vision loss. The condition is life-threatening, but immediate detection and treatment with antiviral drugs can provide the best possible chances for survival.

The JC virus is normally no match for a healthy immune system. It can be picked up in a number of different ways, and once a person has the virus it tends to simply lie dormant in the body. The JC virus only becomes active when the immune system is severely compromised, as can occur after aggressive cancer or AIDS treatments.

Brain and spinal cord cells are lined with an insulating material called myelin. Progressive multifocal leukoencephalopathy destroys myelin, resulting in lesions on the brain that disrupt electrical signaling. Depending on the size, number, and location of lesions, a person may have headaches, nausea, blurred vision, slurred speech, or motor movement difficulties. In addition, some people suffer from memory loss and an inability to concentrate. As the condition worsens, an individual may become paralyzed and enter a comatose state.

When a patient shows signs of neurological problems, he or she is usually scheduled for an extensive series of diagnostic tests. Magnetic resonance imaging and computerized tomography scans reveal brain lesions, and blood tests can show that the JC virus has been reactivated. Once a diagnosis of progressive multifocal leukoencephalopathy is confirmed, specialists can begin considering treatment options.

There are no set strategies for treating progressive multifocal leukoencephalopathy, though doctors generally try a course of antiviral agents. Patients who have AIDS may need to have their medications adjusted so the JC virus can be directly targeted. The drugs used to treat the condition often cause negative side effects, and a patient is usually confined to a hospital bed during treatment so doctors can constantly monitor symptoms.

Recovery times and long-term prognoses are different for each patient. Since the condition is so rare, there is not enough sufficient data to prove that current treatments are entirely worthwhile. Some people start feeling better in as little as one month, while others continue to lose cognitive abilities and ultimately die within a year.