PML Disease

PML Disease (Progressive Multifocal Leukoencephalopath) is an infrequent disorder of the nervous system that primarily affects individuals with suppressed immune systems (including, allograft recipients such as kidney transplant patients; patients with cancers such as leukemia or lymphoma; and nearly 10% of patients with acquired immune deficiency syndrome — AIDS. The disorder, which is caused by a common human polyomavirus, JC virus, is characterized by demyelination or destruction of the myelin sheath that covers nerve cells. The myelin sheath is the fatty covering - which acts as an insulator - on nerve fibers in the brain. Symptoms of PML Disease include mental deterioration, vision loss, speech disturbances, ataxia (inability to coordinate movements), paralysis, and, ultimately, coma reflecting the multifocal distribution of brain lesions. In rare cases, seizures may occur.

Is there any treatment for Progressive Multifocal Leukoencephalopath?

There is no cure for PML Disease, nor is there currently an effective treatment for the disorder. Treatment is symptomatic and supportive.

What is the prognosis of PML Disease?

The course of PML Diseasey is relentlessly progressive. Death usually occurs between 1 and 4 months after onset, but there have been a number of reported cases with survival for months to years.

What research is being done for PML Disease?

The NINDS supports research on demyelinating disorders of the nervous system such as PML Diseasey aimed at increasing scientific understanding of these disorders and finding ways to prevent, treat, and cure the disease utilizing state of the art molecular diagnostic techniques.

Prepared by:
Office of Communications and Public Liaison
National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892