title: Abnormalities of regional brain metabolism in Alzheimer's disease and their relation to functional impairment.
abstract: Resting brain metabolism in patients with Alzheimer's disease (AD) has consistently been demonstrated to be reduced. Moreover, the magnitude of the reduction is related to the severity of dementia. Positron emission tomography (PET), which provides regional metabolic rates for glucose in cross-sectional slices of brain, has demonstrated three alterations in AD that are related to functional deficits. First, whole brain metabolic rate is reduced, and these reductions are related to overall severity of dementia. Second, regional metabolic rates in the association cortices demonstrate relatively greater reductions than are observed in the primary sensory and motor cortices, corresponding to marked impairment of higher cognitive function and relative sparing of sensory and motor function. Third, regional metabolic rates in the association cortices demonstrate increased left-right asymmetry relative to controls. Greater metabolic asymmetry is accompanied by disproportionate neuropsychological deficits in either language or visuospatial function, depending on whether the left or right cerebral hemisphere, respectively, has a lower metabolic rate.
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism* / Q000523:psychology; D001921:Brain / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D003071:Cognition; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008569:Memory Disorders / Q000209:etiology; D014055:Tomography, Emission-Computed
chemical_list: D005947:Glucose