PROTON SPECTROSCOPY OF THE BRAIN IN HIV-INFECTION - CORRELATION WITH CLINICAL, IMMUNOLOGICAL, AND MR-IMAGING FINDINGS

Abnormalities at cerebral proton spectroscopy occur in patients with t he acquired immunodeficiency syndrome (AIDS). N-acetyl aspartate (NAA) is believed to be a neuronal marker, and neuronal loss is thought to underlie the human immunodeficiency virus (HIV)-associated cognitive/m otor complex. The proton spectra in 103 HIV-seropositive patients and 23 control subjects were compared and correlated with clinical, immuno logic, and radiologic measures of HIV infection. Significant (P < .05) reductions in the mean NAA/choline (Cho) and NAA/creatine (Cr) ratios were seen in patients with immune suppression and neurologic signs. S ignificant increases in the Cho/Cr ratios were seen in patients with l ow CD4 lymphocyte counts and abnormal magnetic resonance (MR) images. Reduced NAA ratios correlated with diffuse but not focal MR imaging ab normalities. Combined MR imaging and spectroscopy provides closer rela tionships to clinical and immunologic measures of disease than either modality alone. Spectroscopy is an adjunct to MR imaging and augments the value of an MR imaging study.