Deep gray matter structures in HIV infection: a proton MR spectroscopic study.

PURPOSE: To evaluate the effects of human immunodeficiency virus (HIV) infection on proton metabolites in brain regions carrying the heaviest HIV load.

METHODS

We used two-dimensional proton MR spectroscopy with a preselected volume at the level of the third ventricle to measure N-acetyl-aspartate (NAA) and metabolites containing choline (Cho), and creatine (Cr) in the basal ganglia of eight cognitively impaired subjects who were seropositive for HIV and eight control subjects who were seronegative for HIV. Results are expressed as metabolite ratios.

RESULTS

In the thalamus and lenticular nuclei, NAA/Cr was not different between the two groups. NAA/Cho was decreased in both the thalamus and lenticular nuclei of the HIV-positive group compared with the HIV-negative group. Cho/Cr tended to be increased in both the thalamus and lenticular nuclei of the HIV-positive group.

CONCLUSIONS

The findings suggest no NAA differences between groups, consistent with negligible neuron loss in the region of the brain that carries the heaviest HIV load. The trends toward increased Cho/Cr are consistent with histopathologic findings of infiltration of subcortical gray matter structures with foamy macrophages, microglia, and lymphocytes, or possibly with gliosis.