title: Changes in cognitive function and brain glucose metabolism in elderly women with subjective memory impairment: a 24-month prospective pilot study.
abstract: OBJECTIVE
  Subjective memory impairment (SMI) may precede mild cognitive impairment (MCI) stage and would offer an earlier therapeutic opportunity than MCI would. However, it is not clear whether complaints of forgetfulness are truly reflective of objective memory dysfunction or of impairments in other cognitive domains. The aim of this current longitudinal study was to investigate changes in various cognitive functions and in regional cerebral metabolic rate of glucose (rCMRglc) among elderly women with SMI.
  
  
  METHODS
  Clinical evaluation, comprehensive neuropsychological test, and18F-fluoro-2-deoxyglucose positron emission tomography scans were conducted on 24 women with SMI at the baseline and 24-month follow-up. Changes in the cognitive domain scores and rCMRglc were assessed, and the relationships between them were analyzed.
  
  
  RESULTS
  All participants stayed in SMI all the way till the follow-up, not converted to MCI or dementia. A significant reduction in executive function was found (mean difference in z-score: -0.21, P = 0.02) without changes in other cognitive domains. Declines in rCMRglc were detected in the left superior temporal gyrus, right posterior cingulate gyrus, left parahippocampal gyrus, right lingual gyrus, and right angular gyrus. The change in executive function had a positive correlation with the percent change of rCMRglc in the right posterior cingulate gyrus (β = 0.43, P = 0.02).
  
  
  CONCLUSIONS
  Our findings suggest that elderly women with SMI symptoms should be carefully monitored for declines in executive function and related brain glucose metabolism over time.
authors: Department of Radiology, Incheon St. Mary's Hospital, The Catholic University of Korea, Incheon, South Korea.
authors: H S
authors: HS
authors: Jeong
authors: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors: J S
authors: JS
authors: Park
authors: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors: I U
authors: IU
authors: Song
authors: Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors: Y A
authors: YA
authors: Chung
authors: Division of Life and Pharmaceutical Sciences & College of Pharmacy, Ewha Womans University, Seoul, South Korea.
authors: S J
authors: SJ
authors: Rhie
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000502:physiology; D056344:Executive Function; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008137:Longitudinal Studies; D008569:Memory Disorders / Q000000981:diagnostic imaging* / Q000378:metabolism; D008875:Middle Aged; D010865:Pilot Projects; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose
keywords: brain glucose metabolism; cognitive function; executive function; positive emission tomography; subjective memory impairment