SPECIFICITY OF CHANGES IN CEREBRAL BLOOD-FLOW IN PATIENTS WITH FRONTAL-LOBE DEMENTIA

Eight patients with a clinical diagnosis of probable Alzheimer's disea se, eight patients with the clinical diagnosis of frontal lobe dementi a, and eight controls were examined with single photon emission tomogr aphy (SPECT) using Tc-99-HMPAO. Patients with Alzheimer's disease and those with frontal lobe dementia met DSM-III-R criteria for mild demen tia and were in the early stages of the illness. Compared with patient s with Alzheimer's disease, the group with frontal lobe dementia had s ignificantly lower blood flow in the frontal lobes (dorsolateral and o rbital), the anterior temporal cortex, and the basal ganglia. Within t he frontal lobe dementia group, blood flow was significantly lower in the orbital than in the dorsal frontal cortex, and in the anterior tem poral than in the dorsal temporal cortex. The present study shows the specificity of changes in regional cerebral blood flow in the diagnosi s of different types of dementia, and supports the importance of orbit ofrontal, anterior temporal, and basal ganglia dysfunction in the prod uction of the psychiatric syndrome of frontal lobe dementia.