CEREBRAL PROTON MAGNETIC-RESONANCE SPECTROSCOPY IN ASYMPTOMATIC HIV-INFECTION

Objective: To determine whether proton magnetic resonance spectroscopy (MRS) demonstrates central nervous system abnormalities in asymptomat ic HIV-l-infected individuals. Design: Both prospective and retrospect ive cross-sectional analyses of MRS in asymptomatic HIV-infected indiv iduals. Setting: Two specialist HIV/AIDS outpatient facilities in Lond on. Participants: Eighty-four HIV-1-seropositive asymptomatic men; 29 HIV-1 antibody-negative homosexual men at high-risk for HIV infection and 48 HIV-1 antibody-negative men at low-risk for HIV infection as co ntrols. Main outcome measures: Single voxel, gradient-localized proton MRS performed at 1.5 T with a 135 msec echo-time and 1600 msec repeat -time in an 8 mt volume of interest positioned in the parieto-occipita l white matter. Spectroscopic results were expressed as ratios between the areas under the N-acetyl (NA), creatine (Cr) and choline (Cho) re sonance peaks. Results: There were no differences between those contro ls at high and those at low-risk for HIV infection. Comparing the comb ined control groups with the asymptomatic seropositive patients there were statistically significant differences in NA/Cho, NA/Cr (both P < 0.05) and NA/(NA + Cho + Cr) (P < 0.01). Conclusion: Abnormalities in cerebral biochemistry may be demonstrated by proton MRS during asympto matic HIV-1 infection.