Human immunodeficiency virus-associated neurobehavioural disorder.

AIDS, ARC, and other HIV-associated diseases were originally conceptualised exclusively in terms of defects in cell-mediated immunity and its consequences. But it is now becoming clear that HIV disease can also be a primary neuropsychiatric disorder, although the precise mechanism by which the retrovirus causes impairment in brain function and, ultimately, structural brain damage, remains obscure. The work presented here indicates another shift in our thinking concerning HIV infection. Until recently it was believed that neurological and neuropsychiatric phenomena tended to occur in the late stages of HIV disease. While that might be true for the more severe form of symptomatology that has been termed the AIDS dementia complex, we believe there is at least preliminary evidence that cognitive change can occur earlier in the course of illness, perhaps even in some medically asymptomatic HIV+ individuals. Other investigators have also noted increased neuropsychological abnormality in patients before they developed AIDS or ARC. For example, Janssen et al. found that about half their patients with lymphadenopathy syndrome (LAS) had some neuropsychological test deficits. Durara et al. recently reported on cerebral metabolic rates for glucose in seven HIV+ asymptomatic individuals, compared to 10 HIV- controls. Four of the HIV+ individuals had abnormal asymmetry in frontal and temporal regions suggesting focal reduction in cerebral glucose metabolism. Further indirect evidence that virus can enter the central nervous system early in the course of HIV disease comes from the work of McArthur and associates.(ABSTRACT TRUNCATED AT 250 WORDS)