The term acquired immunodeficiency syndrome, as well as the acronyms Aids and AIDS, refers to a collection of clinical symptoms and symptom complexes associated with specific damage to the immune system caused by the human immunodeficiency virus (HIV) in humans and by variants of HIV (such as simian immunodeficiency virus or SIV) in other mammals. Shortly after the initial infection, both HIV-1 and HIV-2 tend to affect the CNS. As a direct result of this CNS infection, meningitis or encephalitis may occur. During later stages of Aids, when the body's immune function has significantly declined, the affected individual becomes prone to secondary pathology including fever, hypoxia, dehydration, electrolyte disturbances, uraemia, hepatic encephalopathy, cerebral toxoplasmosis, cryptococcal meningitis, progressive multifocal leucoencephalopathy, coc-cidioidomycosis, candidiasis, aspergillosis, histo-plasmosis, cytomegalovirus infection, herpes simplex virus infection, varicella zoster virus infection, lymphoma, and Kaposi's sarcoma.Each of these conditions constitutes a risk factor for the mediation of hallucinatory activity. An additional risk factor stems from the exposure of individuals with Aids to HAART (highly active antiretroviral therapy) and to adjuvant treatment with antibacterial, antifungal, antineoplastic, and antiviral therapeutics. Neuropathological studies indicate that HIV-related diseases of the CNS are located mainly in the subcortical structures of the brain (i.e. the white matter, the basal ganglia, and the hippocampus), as well as in the spinal cord. A type of subcortical dementia that occurs in over 50% of individuals suffering from late-stage Aids is referred to as Aids dementia complex (ADC). Psychiatric symptoms such as agitation, cognitive impairment, disorientation, sleep disturbances, mania, depression, delusions, and hallucinations may develop as a consequence of ADC, as well as the HIV-related disorders listed above. As in other types of dementia, the most prevalent type of hallucinations in ADC is the group of * auditory hallucinations, followed by the group of *visual hallucinations. Due to the considerable variety of structural and metabolic disturbances concomitant to Aids, the pathophysiological mechanisms that mediate those hallucinations are manifold. In clinical practice, they tend to be treated in the same way as hallucinations due to other diseases, i.e. primarily with the aid of antipsychotic medications.
References
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Sewell, D.D., Jeste, D.V., McAdams, L.A., Bailey, A., Harris, M.J., Atkinson, J.H., Chandler, J.L., McCutchan, J.A., Grant, I. (1994). Neuroleptic treatment of HIV-associated psychosis. HNRC group. Neuropsychopharmacol-ogy,10, 223-229.
Alciati, A., Fusi, A., D'Arminio Monforte, A., Coen, M., Ferri, A., Mellado, C. New-onset delusions and hallucinations in patients infected with HIV. Journal of Psychiatry and Neuroscience, 26, 229-234.