Positive and sustained effects of highly active antiretroviral therapy on HIV-1-associated neurocognitive impairment.

Objectives: To determine whether highly active antiretroviral therapy (HAART) is effective in HIV-associated neurocognitive impairment.

Design: An open label, prospective, observational study.

Methods: Since April 1996, 116 patients with advanced HIV infection, reverse transcriptase inhibitor (nRTI) experienced but protease inhibitor (PI) naive, were screened for the presence of neurocognitive impairment. Ninety patients with confounding neurological illness, opportunistic infections or drug abuse were excluded. The remaining 26 patients underwent comprehensive neuropsychological testing, and laboratory measures before, after 6 and after 15 months of treatment with one PI plus two nRTI.

Results: The prevalence of neurocognitive impairment decreased from 80.8% (baseline) to 50.0% (P<0.05) (sixth month) and to 21.7% (P<0.001) (15th month). Among the functions explored, the impairment of concentration and speed of mental processing decreased from 65.4 to 21.7% (P<0.01) and of memory impairment from 50 to 8.7% (P<0.01). Comparing baseline with the sixth and 15th month raw scores, a statistically significant improvement was seen in measures exploring concentration and speed of mental processing (P<0.05), mental flexibility (P<0.05), memory (P<0.05), fine motor functions (P<0.05) and visuospatial and constructional abilities (P<0.01). After 6 months of HAART patients with a normal neuropsychological examination had lower mean plasma viraemia (2.95 versus 3.97 log copies/ml, P<0.05) and greater mean log plasma HIV RNA changes from baseline (-1.84 versus -0.83 log copies/ml, P<0.05) than neuropsychologically impaired subjects.

Conclusion: HAART produces a positive and sustained effect on neurocognitive impairment in HIV-infected patients. A reduction of plasma viral load was associated with the regression of neuropsychological test abnormalities.