Some antiretroviral agents can cross the blood-brain barrier
and therefore decrease viral load in the cerebrospinal fluid. Improvements
in neurocognitive function, however, have been shown even with regimens
not containing cerebrospinal fluid (CSF)–penetrating antiretrovirals.
In a study of 31 patients who received new antiretroviral treatment,
patients whose regimens included CSF-penetrating agents showed greater
reduction in CSF viral load and improved neuropsychological function.
Treatment-naive patients had greater improvement in neuropsychological
function than treatment-experienced patients (29). Other studies
have not shown benefit, and thus the question of whether adding
CSF-penetrating agents is beneficial is still controversial. Other
immunological factors (i.e., chemokines, cytokines, tumor necrosis
factor) are also implicated in the development of neuropathological
changes leading to neurocognitive symptoms. Other factors that contribute
to progression of cognitive disorders include age, concurrent methamphetamine
use, and hepatitis coinfection (29–32).