- JC virus is a papovavirus associated with progressive multifocal leukoencephalopathy.
- Symptoms include mental status changes, weakness, and disorders of gait.
- Characteristic periventricular and subcortical white matter lesions are seen on magnetic resonance imaging (MRI).
- Treatment is with IV immunoglobulin, 0.4 g/kg IV daily for 10 days.
- Relapses are frequent.