- a) neurologic disease unrelated to HIV infection (such as multiple sclerosis, documented stroke, degenerative disease); b) chronic seizure disorders or head injuries if the condition results in functional impairment or is likely to interfere with evaluations; c) central nervous system (CNS) infections or neoplasms (such as toxoplasmosis, primary or metastatic CNS lymphoma, progressive multifocal leukoencephalopathy, cryptococcal or other fungal meningitis, tuberculous CNS infections, or untreated neurosyphilis).