- Evidence of nervous system dysfunction being caused by factors other than HIV infection, including history of head trauma, multiple sclerosis, epilepsy, or presence of concurrent central nervous system (CNS) infections or neoplasms, e.g., toxoplasmosis, primary or metastatic CNS lymphoma, progressive multifocal leukoencephalopathy, cryptococcal or other fungal meningitis, and CNS tuberculous infections.