[Central nervous system involvement in HIV-infected individuals]

Central nervous system (CNS) involvement can occur at any time during human immunodeficiency virus (HIV) infection. Diseases can be primary, caused directly by HIV, or secondary, caused by other agents or induced by other mechanisms, especially tumors and vascular causes. Worsening cellular immunodeficiency creates conditions for opportunistic infections to occur. These include three typical diseases: toxoplasmic encephalitis, cryptococcal meningitis, and progressive multifocal leukoencephalopathy. Antiretroviral therapy has dramatically changed the occurrence of nervous system complications. Opportunistic infections have decreased, and primary cerebral lymphoma is now rare. However, even with effective regimens, at least minimal signs of HIV-associated neurocognitive disorder can be found in many patients. The nervous system can be affected by syphilis, which may present differently in HIV-positive individuals due to the higher risk of treponemal invasion of the CNS. Keywords: human immunodeficiency virus (HIV) infection, HIV-associated neurocognitive disorder (HAND), opportunistic infection, brain toxoplasmosis, progressive multifocal leukoencephalopathy (PML), cryptococcal meningitis, neurosyphilis.