CNS diseases in AIDS

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  • Toxoplasmosis

    • See behavior changes and lots of small abscesses on MRI

    • Almost always treated for in AIDS patients

    • Lots of small abscesses throughout the brain

  • HIV encephalitis

    • Direct infection of brain by HIV (crosses the BBB in macrophages)

    • Seen in 20-30% of AIDS patients

    • See multinucleated giant cells, especially perivascularly

  • AIDS dementia complex

    • Clinical syndrome due to direct CNS infection of brain (still crosses BBB in macrophages)

    • HIV not in neurons, but in microglia (which migrated in as tissue macrophages?) and astrocytes

    • Mechanism unknown because there’s not too much neuronal damage

    • May see some gliosis and vacuolization of the white matter

  • Vacuolar myelopathy

    • Degenerative disease of the spinal cord seen in 20-30% of AIDS patients

    • Maybe due to direct infection of spinal cord by HIV

    • Looks like subacute combined degeneration seen with vitamin B₁₂ deficiency (affects the posterior and lateral columns of the spinal cord), but it’s not associated with deficiency

  • Meningitis (often cryptococcal)

  • Progressive multifocal leukoencephalopathy – is an opportunistic brain infection in AIDS patients caused by JC virus which infects the oligodendrocytes and causes MS-like c/s

Category: Pathology Notes