Cerebral blood flow SPECT with Tc-99m exametazine correlates in AIDS dementia complex stages. A preliminary report

Human immunodeficiency virus (HIV) infection is frequently complicated by a variety of disease processes affecting the central nervous system (CNS). One of them is AIDS dementia complex (ADC), which, in the absence of opportunistic infection, is believed to be caused by HIV itself. ADC is characterized by a constellation of cognitive, motor, and behavioral symptoms that progressively get worse. This study was coined to recruit AIDS patients without any opportunistic CNS infection but with signs of CNS abnormality as evidenced by behavioral and subtle motor changes, then to categorize them into five stages, and finally to perform the cerebral blood flow scan using Ceretec. The aim of this study was to correlate the abnormalities of the brain scan with the different stages of ADC. Five patients were analyzed, with dementias ranging from mild to severe according to Price's classification. After confirming the absence of CNS opportunistic infections and AIDS associated malignancies by CT of the brain, the patients underwent psychiatric evaluation and brain scans. The SPECT scans were very sensitive in showing uptake defects in the brain, even in the early stages of ADC. The blood flow defects were more pronounced in the later stages, while the CT scans remained negative except in patients with the most severe dementia.