John Cunningham virus

• CNS infection with JC virus, usually in the context of HIV infection

Background

Epidemiology

• HIV patients

Clinical Presentation

• Classic PML
  • Subacute onset of focal central neurological lesions
  • Asymmetric, well-demarcated, nonenchancing subcortical white matter lesions on MRI
• PML-IRIS
  • Focal central neurological lesions following immune recovery
  • Contrast enhancing lesions with or without mass effect on MRI
• JCV granule cell neuropathy
  • Chronic cerebellar dysfunction
  • Cerebellar atrophy on MRI
• JCV encephalitis
  • Subacute onset of encephalopathy
  • Cortical lesions on MRI
• JCV meningitis
  • Chronic headaches
  • Ventriculomegaly on MRI

Investigations

• MRI head: white matter changes
• CSF: fairly nonspecific, with mild pleocytosis, slightly elevated protein, and normal glucose
  • PCR of CSF has sensitivity 58% with ART or 72-92% without, and specificity 92-100%

Diagnosis

• JC virus PCR of CSF or brain biopsy

Treatment

• Antiretroviral therapy for HIV