"Our research indicates that the subgroup of patients with the 'hardest to treat' neurocognitive impairment condition is the one with the most severe neurocognitive impairment at HAART initiation," Dr. Valerio Tozzi from National Institute for Infectious Diseases IRCCS Lazzaro Spallanzani, Rome, told Reuters Health. "HAART improves neurocognitive functioning but, in our experience, the greater is the impairment, the lower is the probability of its full reversal."

Dr. Tozzi and colleagues studied 94 HIV-infected patients. During mean follow-up of 63 months, only 37.2% of patients had reversible neuropsychological deficits, the authors report, and the 65-month probability of showing persistent deficits despite HAART was 53.0%.

Persistent neuropsychological deficits were associated with lower education level and higher prevalence of hepatitis C virus-positive serology, the results indicate, but not with CDC stage, baseline CD4 cell count or viral load, virologic response to HAART, or changes in CD4 cell count or viral load during HAART.

Patients with persistent neuropsychological deficits performed worse on the composite concentration and speed of mental processing z score and on the composite memory z score, the researchers note.

The 65-month probability of persistent deficits was higher in patients with composite NPZ8 scores below the median (87%) than above the median (30%), the report indicates.

In a multivariable Cox model, poor performance on the baseline composite NPZ8 global score was the strongest predictor of persistent neuropsychological deficits, with each one-point decrease tripling the probability of remaining impaired despite long-term HAART.

"We believe that HAART should be started as soon as HIV-related neurocognitive impairment is diagnosed, even in patients with 'high' CD4 cell counts, to stop, as soon as possible, the neurological damage," Dr. Tozzi said. "For patients that are not responding neurologically, the presence of other potentially confounding and treatable conditions that could affect cognition (depression, alcohol or other substance abuse, HIV-related CNS diseases, HCV co-infection) should be re-evaluated."

J Acquir Immune Defic Syndr 2007;45:174-182

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