title: Global cerebral blood flow in relation to cognitive performance and reserve in subjects with mild memory deficits.
abstract: OBJECTIVE
  This study was undertaken to explore the mechanisms underlying cognitive reserve in subjects with mild memory deficits by using positron emission tomography (PET).
  
  
  METHODS
  Global cerebral blood flow (gCBF) and cerebrovascular reserve (CVR) measurements were performed in 15 elders (5 men, 10 women, 62-84, 71.8 +/- 6.2 years) meeting criteria for mild cognitive impairment (MCI). PET consisted of quantitative [(15)O]water determinations of CBF, two at baseline and one postadministration of acetazolamide (ACZ).
  
  
  RESULTS
  Mean gCBF were 44.9 +/- 5.5 during counting, 44.5 +/- 6.7 for the memory task, and 60.2 +/- 4.8 ml/min/100 g for post-ACZ (CVR of 33.9 +/- 13.2%). Task-related gCBF change was significantly related to memory score, performance on the Trail Making Test B (Trails-B), premorbid IQ, and education, and differed significantly between the learning-based groups.
  
  
  CONCLUSIONS
  Cognitive reserve appears analogous to cardiac reserve. The ability to alter gCBF paralleled performance on general cognitive measures, was enhanced in higher levels of cognitive reserve, and was impaired in individuals who no longer appear to benefit from repeated exposure to testing.
authors.affiliation: Positron Emission Tomography Imaging Center, Department of Radiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa, IA 52242, USA. laura-ponto@uiowa.edu
authors.forename: Laura L
authors.initials: LL
authors.lastname: Boles Ponto
authors.forename: Vincent A
authors.initials: VA
authors.lastname: Magnotta
authors.forename: David J
authors.initials: DJ
authors.lastname: Moser
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Duff
authors.forename: Susan K
authors.initials: SK
authors.lastname: Schultz
mesh_terms: D000086:Acetazolamide / Q000627:therapeutic use*; D000368:Aged; D001519:Behavior; D002531:Cerebellum / Q000098:blood supply*; D002560:Cerebrovascular Circulation; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000097:blood* / Q000453:epidemiology / Q000503:physiopathology; D049268:Positron-Emission Tomography / Q000379:methods*; D012189:Retrospective Studies; D014706:Verbal Learning / Q000187:drug effects
chemical_list: D000086:Acetazolamide