LOCALIZED CEREBRAL PROTON MR SPECTROSCOPY IN HIV-INFECTION AND AIDS

PURPOSE: To document differences in the cerebral proton MR spectra of patients with early and late stages of human immunodeficiency virus (H IV) infection. METHOD: We studied the relative N-acetyl-aspartate (NAA ) levels by localized proton spectroscopy of the parietooccipital regi on of the brain in 43 HIV-seropositive patients, including 26 with an acquired immunodeficiency syndrome (AIDS)-defining diagnosis, and in e ight control subjects. RESULTS: Reduced relative NAA levels were shown in those HIV-1-seropositive patients: 1) with AIDS against HIV1-serop ositive patients without AIDS (P <.04); 2) with HIV1-associated cognit ive/motor complex against neurologically healthy patients (P <.007); 3 ) with encephalopathic changes on MR against those with normal imaging (P <.001); and 4) on follow-up against their results on initial study (P < .03). CONCLUSIONS: By clinical (Centers for Disease Control clas sification) and radiologic (MR evidence of white-matter disease) crite ria indicating late-stage HIV infection, reduced relative levels of NA A have been demonstrated Spectroscopic abnormalities can be quantitati vely tracked with time. This paper demonstrates the clinical use of de tecting NAA as a putative in vivo measure of the neuronal loss that ha s been demonstrated in postmortem studies of patients with AIDS. This neuronal loss, which is believed to underlie the HIV-1-associated cogn itive/motor complex, is thought to be attributable directly or indirec tly to the presence of HIV in the brain. Proton spectroscopy may serve as a quantitative noninvasive indicator of this aspect of cerebral in volvement in HIV disease.