Proton spectroscopy of the brain in HIV infection: correlation with clinical, immunologic, and MR imaging findings.

Abstract

Abnormalities at cerebral proton spectroscopy occur in patients with the 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/motor complex. The proton spectra in 103 HIV-seropositive patients and 23 control subjects were compared and correlated with clinical, immunologic, 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. Significant increases in the Cho/Cr ratios were seen in patients with low CD4 lymphocyte counts and abnormal magnetic resonance (MR) images. Reduced NAA ratios correlated with diffuse but not focal MR imaging abnormalities. Combined MR imaging and spectroscopy provides closer relationships 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.

JC Virus Infection of the Brain

“…115 In the early stage of HIV infection, when clinical symptoms are absent or mild, NAA/Cr is unchanged (92%-98% of normal value). [116][117][118][119] With the development of the AIDS complex, NAA/Cr decreases (62%-84% of normal value). [116][117][118][119] The metabolic abnormalities increase proportionally with the severity of the disease.…”

Effects of Methamphetamine Dependence and HIV Infection on Cerebral Morphology

“…It is clear from these studies that even in the absence of CNS opportunistic infections, HIV infection is accompanied by damage to cerebral white matter (which results in progressive loss of white matter volume) and by more circumscribed progressive loss of cerebral gray matter, particularly in the striatum. These studies are complemented by magnetic resonance spectroscopy (MRS) studies that have shown widespread reductions in the neural marker N-acetylaspartate and increases in neuroinflammatory markers commensurate with the disease stage and degree of functional impairment (9)(10)(11)(12)(13)(14)(15). The MRS studies, like the structural MRI studies, suggest early damage to the striatum and subcortical white matter as well as eventual cortical gray matter degeneration.…”

Magnetic resonance spectroscopy reveals that activated monocytes contribute to neuronal injury in SIV neuroAIDS

“…Moreover, we have recently found that transient changes in NAA/Cr best correlated with changes in synaptophysin levels during acute SIV infection in the macaque (43). 1 H MRS has been widely used to study HIV-infected patients, and early studies reported profound decreases in NAA/Cr (24,(44)(45)(46)(47)(48); such drops are less dramatic in the current highly active antiretroviral therapy (HAART) era. Improvement in NAA/Cr, along with neurocognitive improvement, has been reported following treatment with HAART (22,25), which parallels the effect of treatment in the model reported here.…”