[Positron emission tomographic studies using C-11-glucose in normal aging and cerebrovascular dementia]

Abstract

Seven normal volunteers and 11 patients with cerebrovascular dementia were studied about the relations between effect of aging, severity of dementia, cerebral glucose metabolism and metabolic response to verbal stimuli by positron emission tomography (PET) using C-11-glucose administered orally. The diagnosis of cerebrovascular dementia was done according to the Hachinski's ischemic score and X-ray CT findings, and the severity of dementia was classified according to the DR scale originated by Hasegawa. PET scanning started at 10 minutes and ended at 50 minutes after administration of C-11-glucose, and bloods were sampled at every 5-10 minutes during the PET scanning . Stimulation studies were performed after 3 or 7 days from control studies. An educational broadcasting program was used as the verbal stimuli. Regional distribution of glycogenic metabolites (RDGM: mg/100 g brain), which was a semi-quantitation of the pool of glycogenic metabolites mainly amino acids, were calculated. The RDGM values in elder normal subjects were significantly low compared with young normal subjects in frontal cortex (p less than 0.05). The decline in frontal cortex metabolism could have been caused by the morphological changes in the course of aging. In temporal cortex, there was no significance between two groups. RDGM increased significantly respond to the verbal stimuli in frontal and temporal cortex both young and elder normal subjects. The RDGM values in vascular dementias were significantly low (p less than 0.001) compared with elder normal subjects' in frontal and temporal cortex. Significant difference existed between mild and severe dementia in frontal cortex (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)