No abstract

The borderline zone condition between normal aging and dementia is a major issue of concern. Although the term mild cognitive impairment (MCI) is popular, its prevalence and neuropsychological features have not been fully investigated. We investigated the prevalence and neuropsychological features for Clinical Dementia Rating (CDR) 0.5 and MCI. For normal aging, the effects of age and educational level on cognitive performance were examined. We examined 1501 older residents (46.8%) in Tajiri 65 years of age and older. They performed the Cognitive Abilities Screening Instrument (CASI). Depressive scores and subjective memory complaints were also evaluated. There was no age effect but an educational effect on cognitive performance in healthy adults. We found the overall prevalence of CDR 0.5 to be 30.2%, whereas that of MCI was only 4.9%. All CASI domains were deteriorated except for long-term memory and visual construction in the CDR 0.5 participants compared with healthy adults, suggesting that CDR 0.5 is similar to very mild Alzheimer disease. Memory complaints' data suggested that it would be better to exclude memory complaints from the MCI criteria. We considered that the concept of CDR 0.5 would be more applicable to community residents rather than that of the MCI.

Background: The borderline condition between health and dementia, defined as Clinical Dementia Rating (CDR) 0.5, should be detected for the possible prediction of dementia. Since the CDR requires information from collateral sources, it is difficult to rate people living alone. The aim is to develop a set of tests without collateral information for detecting CDR 0.5 and converters to dementia. Methods: 625 participants were selected from the community; 412 were CDR 0 (healthy), 168 were CDR 0.5 (defined here as mild cognitive impairment; MCI), and were 45 CDR 1+ (dementia). Neuropsychological tests were administered to assess memory, orientation, attention and executive function. We analyzed various combinations of tests by receiver operating characteristic curve and area under the curve (AUC). Among the participants, 497 were randomly selected to be re-examined after 5 years to predict further decline towards dementia. Results: We found that a combination of tests for orientation, memory, attention, executive function, and abstraction and judgment could discriminate subjects with MCI from healthy participants with high accuracy (AUC = 0.83). The predictive accuracy was better than that of the Mini Mental State Examination (AUC = 0.77). The same tests, except orientation, could also predict converters to dementia (AUC = 0.88). Conclusions: We consider that a combination of tests can be helpful for the early detection of individuals with MCI and converters to dementia in the community.

Deficits in the cholinergic system are pronounced in dementia with Lewy bodies (DLB) and are more severe in patients with visual hallucinations (VHs). The aim is to identify the occipital glucose metabolism patterns by positron emission tomography (PET) and the changes following donepezil treatment. 13 DLB patients with VHs were enrolled in the study. After the first FDG-PET study, 5 mg/day donepezil was administered orally, and a second PET study was performed 3 months later. After donepezil administration, VHs disappeared completely in 6 patients, and the PET studies revealed significantly decreased glucose metabolism in the medial occipital cortex. These results suggest that VHs in DLB were associated with impaired glucose metabolism in the medial occipital cortex. Donepezil treatment may modify regional glucose metabolism.