Cerebrospinal fluid analysis for the diagnosis of human immunodeficiency virus-related neurologic diseases.

Although early attempts demonstrated increased amounts of p24 antigen in the cerebrospinal fluid (CSF) of AIDS patients with dementia (HADC), gene amplification based assays have recently shown a correlation between the HI virus load in CSF and dementia. Although these correlations are valid for a large population, current evidence does not favor the use of CSF HI virus load measurement for the diagnosis of HADC. By polymerase chain reaction, opportunistic infections of the central (CNS) and peripheral nervous system due to cytomegalovirus, JC virus, and herpes simplex virus types 1 and 2 and primary lymphoma caused by Epstein-Barr virus can be diagnosed with an overall sensitivity ranging from 76% to 98% and a specificity between 98% and 99.5%. In contrast, bacterial, protozal, and fungal infections of the CNS are still better diagnosed by conventional assays such as culture, antigen detection, and empirical therapy. Brain biopsy still remains the ultimate means of obtaining a specific diagnosis in selected cases.