title: Age and Vascular Burden Determinants of Cortical Hemodynamics Underlying Verbal Fluency.
abstract: BACKGROUND
  Aging processes and several vascular burden factors have been shown to increase the risk of dementia including Alzheimer's disease. While pathological alterations in dementia precede diagnosis by many years, reorganization of brain processing might temporarily delay cognitive decline. We hypothesized that in healthy elderly individuals both age-related neural and vascular factors known to be related to the development of dementia impact functional cortical hemodynamics during increased cognitive demands.
  
  
  METHODS
  Vascular burden factors and cortical functional hemodynamics during verbal fluency were assessed in 1052 non-demented elderly individuals (51 to 83 years; cross-sectional data of the longitudinal TREND study) using functional near-infrared spectroscopy (fNIRS). The prediction of functional hemodynamic responses by age in multiple regressions and the impact of single and cumulative vascular burden factors including hypertension, diabetes, obesity, smoking and atherosclerosis were investigated.
  
  
  RESULTS
  Replicating and extending previous findings we could show that increasing age predicted functional hemodynamics to be increased in right prefrontal and bilateral parietal cortex, and decreased in bilateral inferior frontal junction during phonological fluency. Cumulative vascular burden factors, with hypertension in particular, decreased left inferior frontal junction hemodynamic responses during phonological fluency. However, age and vascular burden factors showed no statistical interaction on functional hemodynamics.
  
  
  CONCLUSIONS
  Based on these findings, one might hypothesize that increased fronto-parietal processing may represent age-related compensatory reorganization during increased cognitive demands. Vascular burden factors, such as hypertension, may contribute to regional cerebral hypoperfusion. These neural and vascular hemodynamic determinants should be investigated longitudinally and combined with other markers to advance the prediction of future cognitive decline and dementia.
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tuebingen, Tuebingen, Germany; Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany; German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Heinzel
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany; Geriatric Center, University Hospital Tübingen, Tübingen, Germany.
authors.forename: Florian G
authors.initials: FG
authors.lastname: Metzger
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany.
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Ehlis
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Korell
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Alboji
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany.
authors.forename: Florian B
authors.initials: FB
authors.lastname: Haeussinger
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tuebingen, Tuebingen, Germany.
authors.forename: Isabel
authors.initials: I
authors.lastname: Wurster
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tuebingen, Tuebingen, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Brockmann
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tuebingen, Tuebingen, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Suenkel
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany; Geriatric Center, University Hospital Tübingen, Tübingen, Germany.
authors.forename: Gerhard W
authors.initials: GW
authors.lastname: Eschweiler
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tuebingen, Tuebingen, Germany; German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Maetzler
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tuebingen, Tuebingen, Germany; German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Berg
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Fallgatter
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000502:physiology* / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology; D003430:Cross-Sectional Studies; D003704:Dementia / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D012307:Risk Factors; D019265:Spectroscopy, Near-Infrared; D014705:Verbal Behavior / Q000502:physiology*