HIV is a neurotropic virus and can be engulfed.by macrophagocytes.It invades the brain tissue via the blood-brain barrier and multiplies in the cerebrospinal fluid (CSF).HIV has been isolated from the brain,spinal marrow,peripheral nerve,and the CSF.Electronic microscopy,immunohistochemistry,and in situ hybridization have demonstrated monocytes and multinucleated cells containing HIV virus.1 HIV-1 DNA sequences were detected using polymerase chain reaction (PCR) and a significant correlation was proved between the number of HIV copies and the pathological changes (Figure 1).