Patterns of Relative Cerebral Blood Flow in Minor Cognitive Motor Disorder in Human Immunodeficiency Virus Infection

Individuals infected with HIV are at risk to develop cognitive impairment during the course of their disease. Although many patients develop an HIV-associated dementia, others may develop the less severe minor cognitive motor disorder (MCMD). In this study, relative cerebral blood flow was measured with PET imaging in HIV+ MCMD patients, HIV+ control subjects, and HIV– control subjects; analyses were performed by using statistical parametric mapping. Comparing a short-term memory task versus a rest state yielded activation in superior temporal cortex, postcentral gyrus, and cerebellum in all three subject groups. Comparing long- and short-term memory tasks yielded activation throughout the frontal cortex, including BA46. Activation in this area was reduced in the HIV+ control subjects and further reduced in the MCMD+ patients. Thus, brain activation associated with lower-level, automatic processing appears normal in HIV+ MCMD+ subjects, but activation associated with effortful retrieval and organizational processes is abnormal.