Neurocognitive complications of HIV disease

Neurocognitive complications are the most common sequelae of HIV infection if the full spectrum of HIV disease-from initial seroconversion to death fr om advanced AIDS-is considered. Though resembling subcortical neurological disorders from a neuropsychological standpoint the presentation is variable , and almost any pattern can be seen. Although neuropsychological impairmen t is often subtle, it can affect day-to-day life and is associated with ear lier mortality. It is not clear if milder forms of neurocognitive disturban ce necessarily presage advanced dementia, and current data suggest a two-fa ctor model: a subacute relapsing-remitting condition that can occur at any stage of HIV disease and a progressive, more fulminant dementia. The pathol ogical substrates of these conditions are not well characterized, although recent data support the notion that synaptodendritic damage underlies the n europsychological impairment, and may precede the neuronal loss and other p athological features more characteristic of HN encephalitis. Some reversibi lity of neurocognitive disturbance has been reported with zidovudine therap y, though the data are not consistent. New regimens involving protease inhi bitors need to be evaluated in terms of benefit to the central nervous syst em because many drugs of this class do not penetrate the blood-brain barrie r efficiently Finally, studies utilizing experimental treatments that may a ffect the putative mechanisms of neural injury are in progress.