Neuropsychological detection of the early stage of amnestic mild cognitive impairment without objective memory impairment

Aim: We investigate the assessment method to detect the early stage of amnestic mild cognitive impairment (aMCI) using Wechsler Memory Scale – Revised (WMS-R) and Wechsler Adult Intelligence Scale – Third Edition (WAIS-III). Methods: Three groups (normal group, aMCI group, and early aMCI group), controlled for age and years of education, underwent brain 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET), WAIS-III, WMS-R, and other tests. The early aMCI group does not fulfill the clinical diagnostic criteria of aMCI because patients do not have objective memory impairment, but their clinical symptoms and results of 18F-FDG PET indicate that they should be included in the category of aMCI. Results: The discrepancy of scores between Verbal IQ and General Memory had the highest accuracy in discriminating between normal and early aMCI groups. Conclusion: The cutoff point determined in this study is useful to detect an early stage of aMCI, which may be distinguished from aMCI using the current criteria.