A 33 year old woman with a 15 year history of drug abuse who is being treated for fever, cough, and shortness of breath, develops dementia, hemiparesis, ataxia, aphasia, and dysarthria over the course of 5 days. MRI reveals multiple white matter lesions. Over the course of 2 weeks, the woman’s condition worsens, Despite aggressive treatment, she lapses into a coma and soon dies. At autopsy, histologic examination of her brain tissue reveals gigantic, deformed astrocytes and oligodendrocytes with abnormal nuclei.
What is the most likely cause of this woman’s CNS symptoms?
1.Autoimmune attack of myelin sheaths
2.A double stranded circular DNA virus
3.A single stranded linear RNA virus
4.An autosomal recessive lysosomal storage disease
5.A proteinaceous infectious particle
Explanation:
JC virus is a ubiquitous polyomavirus that causes progressive multifocal leukoencephalopathy (PML). PML is associated with severely immunocompromised states. Most cases are seen in patients with AIDS. The disease can have a very rapid course, progressing over days or weeks. A CD4 count less than 100 is an especially poor prognostic sign in these patients. Characteristic histologic findings include giant astrocytes, and oligodendrocytes with enlarged nuclei and nuclear inclusions. Radiographic findings include numerous white matter lesions of varying sizes in the cerebral and cerebellar hemispheres.