Cerebral Single-Photon Emission Computed Tomography Abnormalities in Human Immunodeficiency Virus Type 1-Infected Gay Men Without Cognitive Impairment

To determine whether technetium Tc 99m exametazime single-photon computed emission tomography (SPECT) can distinguish gay human immunodeficiency virus (HIV)—positive subjects, both with and without mild cognitive impairment, from gay HIV-negative control subjects. Twenty HIV-positive subjects (12 without cognitive impairment and eight with mild cognitive impairment) and 10 HIV-negative subjects underwent neurological, neuropsychological, magnetic resonance imaging, and technetium Tc 99m exametazime SPECT examinations. Subjects were recruited from a natural history study of gay men with HIV infection. Subjects from the cohort who had previously participated in a magnetic resonance imaging study were selected for the SPECT study. The SPECT scans were rated as abnormal if focal defects, confirmed by a horizontal profile analysis, were seen. Sixty-seven percent of HIV-positive subjects without cognitive impairment, 88% of HIV-positive subjects with mild cognitive impairment, and 20% of HIV-negative subjects had abnormal SPECT scans (P<.05 for both HIV-positive groups when each group was compared with HIV-negative subjects). Compared with gay HIV-negative control subjects, focal SPECT defects are seen with an increased frequency in HIV-positive gay men without cognitive impairment and in HIV-positive gay men with mild cognitive impairment.