Progressive multifocal leukoencephalopathy

This incredibly rare disease caused by a reactivation of the JC virus and 0is found worldwide. Often, it occurs as an opportunistic infection in those who are immunosuppressed. The symptoms of the disease include ataxia, dementia, visual field defects, focal or generalized weakness of the extremities, speech disturbaces. Within four to six months, the disease leads to a coma and death. The virus infects and kills the oligodendrocytes, which leads to demyelination (which can be seen on CT and MRI scans). No effective treatment has been found.