Patterns of relative cerebral blood flow in minor cognitive motor disorderin human immunodeficiency virus infection

Individuals infected with HIV are at risk to develop cognitive impairment d uring the course of their disease. Although many patients develop an HIV-as sociated 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- con trol subjects; analyses were performed by using statistical parametric mapp ing. Comparing a short-term memory task versus a vest state yielded activat ion in superior temporal cortex, post-central gyrus, and cerebellum in all three subject groups. Comparing long- and short-term memory tasks yielded a ctivation throughout the frontal cortex, including BA46. Activation in this area was reduced in the HIV+ control subjects and further reduced in the M CMD+ patients. Thus, brain activation associated with lower-level, automati c processing appears normal in HIV+ MCMD+ subjects, but activation associat ed with effortful retrieval and organizational processes is abnormal.