A multicenter in vivo proton-MRS study of HIV-associated dementia and its relationship to age.

OBJECTIVE: Differences in diagnostic criteria and methods have led to mixed results regarding the metabolite pattern of HIV-associated brain injury in relation to neurocognitive impairment. Therefore, a multicenter MRS consortium was formed to evaluate the neurometabolites in HIV patients with or without cognitive impairment. METHODS: Proton magnetic resonance spectroscopy (MRS) at short-echo time (30 ms) was assessed in the frontal white matter, basal ganglia, and parietal cortex of 100 HIV patients [61 with AIDS dementia complex (ADC) and 39 neuroasymptomatic (NAS)] and 37 seronegative (SN) controls. RESULTS: Compared to SN, NAS had higher glial marker myoinositol-to-creatine ratio (MI/Cr) in the white matter (multivariate analyses, adjusted P=0.001), while ADC showed further increased MI/Cr in the white matter and basal ganglia (both P<0.001), and increased choline compounds (Cho)/Cr in white matter (P=0.04) and basal ganglia (P<0.001). Compared to NAS, ADC showed a reduction in the neuronal marker N-acetyl compound (NA)/Cr in the frontal white matter (P=0.007). CSF, but not plasma, viral load correlated with MI/Cr and Cho/Cr in white matter and NAA/Cr in parietal cortex. HIV infection and aging had additive effects on Cho/Cr and MI/Cr in the basal ganglia and white matter. CONCLUSIONS: The results suggest that glial activation occurs during the NAS stages of HIV infection, whereas further inflammatory activity in the basal ganglia and neuronal injury in the white matter is associated with the development of cognitive impairment. Aging may further exacerbate brain metabolites associated with inflammation in HIV patient and thereby increase the risk for cognitive impairment.

The response of symptomatic neurosyphilis to high-dose intravenous penicillin G in patients with human immunodeficiency virus infection.

BACKGROUND: Infection with the human immunodeficiency virus (HIV) may affect both the natural course of syphilis and the response to treatment. We examined the response to treatment with high-dose penicillin G in HIV-infected patients with symptomatic neurosyphilis. METHODS: Neurosyphilis was defined by reactivity in serum treponemal tests for syphilis, neurologic manifestations consistent with neurosyphilis, and a positive Venereal Disease Research Laboratory (VDRL) test on cerebrospinal fluid. We identified 11 HIV-infected patients with symptomatic neurosyphilis; 5 had been treated previously for early syphilis with penicillin G benzathine. Patients were treated with 18 million to 24 million units of penicillin G per day administered intravenously for 10 days. Cerebrospinal fluid was examined approximately 6 and 24 weeks after treatment, when the polymerase chain reaction and rabbit inoculation were used to detect Treponema pallidum. RESULTS: In four of the seven patients studied 24 weeks after treatment, the serum titers on rapid plasma reagin (RPR) testing decreased by at least two doubling dilutions, and four patients had reductions in the cerebrospinal fluid titers on VDRL testing or reverted to nonreactive results. In two patients there was no normalization or improvement in serum titers on RPR testing or cerebrospinal fluid titers on VDRL testing, cell counts, or protein concentrations. One patient relapsed with meningovascular syphilis six months after therapy. T. pallidum was detected by the polymerase chain reaction in cerebrospinal fluid from 3 of 10 patients before treatment, but in none of the 10 post-treatment specimens. CONCLUSIONS: In patients with early syphilis who are also infected with HIV, therapy with penicillin G benzathine may fail, and neurosyphilis may develop. The regimen of high-dose penicillin recommended for neurosyphilis is not consistently effective in patients infected with HIV.