A COMPARISON OF CEREBRAL SPECT ABNORMALITIES IN HIV-POSITIVE HOMOSEXUAL MEN WITH AND WITHOUT COGNITIVE IMPAIRMENT

Objective: To determine whether technetium Tc 99m exametazime (HMPAO) single-photon emission computed tomography (SPECT) can distinguish bet ween human immunodeficiency virus (HIV)-positive homosexual men with n ormal neuropsychologic test results and HIV-positive homosexual men wi th abnormal neuropsychologic test results. Design: Neurologic, neurops ychologic, magnetic resonance imaging, and Tc 99m HMPAO SPECT examinat ions were performed on 10 HIV-positive homosexual men without cognitiv e impairment and five HIV-positive homosexual men with cognitive impai rment. Patients: Human immunodeficiency virus-positive homosexual men from New York City were recruited for the study. Main Outcome Measures : Findings on SPECT scans were evaluated qualitatively for focal defec ts, heterogeneity of the cortical margin, white matter hypoperfusion, and decreased global cortical uptake. All SPECT focal defects were cor egistered with magnetic resonance images; SPECT heterogeneity and glob al cortical uptake were also measured quantitatively. Results: Coregis tration with magnetic resonance imaging revealed that 63% of the focal SPECT defects corresponded to brain gyri and 37% corresponded to sulc i. There was no significant difference in the frequency of qualitative or quantitative SPECT abnormalities between HIV-positive homosexual m en with and without cognitive impairment. However, after examining ind ividual neuropsychologic test factors, impaired motor speed performanc e was associated with decreased quantitative global cerebral uptake. C onclusions: Qualitative SPECT abnormalities are not increased in frequ ency in HIV-positive homosexual men with global cognitive impairment c ompared with those in HIV-positive homosexual men without cognitive im pairment. Impaired motor speed performance may be associated with decr eased quantitative global cerebral uptake.