title: Detection of early amnestic mild cognitive impairment without significantly objective memory impairment: a case-controlled study.
abstract: BACKGROUND
  We encountered eight early amnestic mild cognitive impairment (aMCI) patients (early MCI group) who did not fulfill the diagnostic criteria for aMCI. We compared the scores of neuropsychological examinations as well as the cerebral metabolic rate for glucose consumption (CMRglc) decrease on (18)F-FDG PET examination between the early MCI group and 10 aMCI patients (MCI group) or six normal elderly subjects (normal group), to examine whether the current diagnostic criteria can detect early-stage aMCI.
  
  
  METHODS
  The three groups underwent Mini-Mental State Examination (MMSE), Wechsler Adult Intelligence Scale - Third Edition (WAIS-III), Wechsler Memory Scale Revised (WMS-R), magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) examinations.
  
  
  RESULTS
  The early MCI group did not show significant memory impairment of 1.0 SD or other cognitive dysfunctions on neuropsychological examinations, and did not fulfill the diagnostic criteria of aMCI. With one-way anova and Tukey's HSD post-hoc test, the early MCI group showed the highest scores for WAIS-III, whereas the MCI group showed the lowest scores for WMS-R, although there were no significant differences between the early MCI and normal groups. In order to show a discrepancy in scores between WAIS-III and WMS-R, we subtracted the scores of WMS-R from WAIS-III. Consequently, the normal group showed significantly smaller differences in scores than the other groups, although there were no significant differences between the early MCI and MCI groups. (18)F-FDG PET recognized a CMRglc decrease in the posterior cingulate gyrus and/or part of the parietotemporal area in both the MCI and early MCI groups, of which the extent and magnitude were weaker in the early MCI group. The normal group did not show a significant CMRglc.
  
  
  CONCLUSIONS
  The early MCI group should be included in aMCI not only based on the discrepancy between intelligence and memory scores, but also based on the (18)F-FDG PET findings. The combination of these examinations would make it possible to diagnose early-stage aMCI.
authors.affiliation: PET/CT Dementia Research Center, Juntendo Tokyo Koto Geriatric Medical Center, Tokyo, Japan. murayama@juntendo.gmc.ac.jp
authors.forename: Norio
authors.initials: N
authors.lastname: Murayama
authors.forename: Eizo
authors.initials: E
authors.lastname: Iseki
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Fujishiro
authors.forename: Ryoko
authors.initials: R
authors.lastname: Yamamoto
authors.forename: Kazumi
authors.initials: K
authors.lastname: Ota
authors.forename: Masaru
authors.initials: M
authors.lastname: Suzuki
authors.forename: Kiichi
authors.initials: K
authors.lastname: Nagashima
authors.forename: Heii
authors.initials: H
authors.lastname: Arai
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Sato
mesh_terms: D000368:Aged; D000647:Amnesia / Q000150:complications / Q000175:diagnosis; D000704:Analysis of Variance; D001921:Brain / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D019788:Fluorodeoxyglucose F18; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000453:epidemiology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D012720:Severity of Illness Index
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18