Computerized tomographic diagnostic aspects of acquired immunodeficiency syndrome

The involvement of the CNS in patients with AIDS is frequent such that 80 percent of patients have evidence of CNS disease at autopsy. The clinical manifestations are quite varied. These disorders may be divided into two groups: (1) direct effect of the human immunodeficiency virus (HIV) on the nervous system, for example, aseptic meningitis, subacute encephalitis, granulomatous angitis; (2) indirect effects of HIV on the nervous system which are due to immunodysfunction. In the later group, CNS infections (cerebral toxoplasmosis, herpes simplex encephalitis, neurosyphilis, fungal infections, tuberculosis) and unusual CNS neoplasms (Kaposi's sarcoma, primary and secondary brain lymphomas) are the disorders most commonly involving the nervous system. In many of these disorders, the computerized tomographic (CT) findings are helpful in detecting the presence of the abnormality; however, the CT findings are not sufficiently characteristic to permit specific pathological diagnosis without utilization of brain biopsy or CSF findings (including cytological examination and extensive studies for infectious agents). The most common nervous system conditions which complicate AIDS are reviewed emphasizing the conditions in which computerized tomographic findings are most helpful in delineating the pathological condition.