[Cerebral glucose metabolism in dementia (PET-FDG study)]

Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) was employed to assess regional cerebral glucose metabolism which is tightly coupled to neuronal activity in the brain. In Alzheimer's and multi-infarct dementia, hypometabolism of glucose was found in frontal, temporal, and parietal association cortices. Focal hypometabolism in association cortices was observed in depression, epilepsy, ALS and other neurological diseases without any symptoms of mental deterioration. These results might indicate that not focal but global decrease of neuronal activity in the association cortex induces demented state.