title: Impact of homocysteine on cortical perfusion and cognitive decline in mild Alzheimer's dementia.
abstract: OBJECTIVE
  Elevated plasma total homocysteine level (tHcy) is associated with increased risk of dementia via increased white matter changes or reduction in cortical volume. Whether tHcy has an independent impact on regional perfusion and if it can predict a more rapid cognitive decline in mild Alzheimer dementia (AD) warrants investigation.
  
  
  METHODS
  Eighty AD patients with a clinical dementia rating of 1 were enrolled. Their Cognitive Ability Screening Instrument (CASI) scores on enrolment and after 1 year of follow-up as well as their perfusion index (PI) from single photon emission computed tomography upon enrolment were analyzed.
  
  
  RESULTS
  In cross-sectional analysis, elevated tHcy was associated with lower frontal PI independent of cerebrovascular risk factors (β = -0.35, P = 0.009). The CASI scores correlated with temporo-parietal PI (Pearson r range 0.3-0.39, P < 0.01) but not with tHcy or frontal PI. By longitudinal analysis, only tHcy level was related to a more rapid cognitive decline (odds ratio for executive function score 1.82; odds ratio for total CASI score 1.74).
  
  
  CONCLUSIONS
  Cognitive performance in mild AD can be reflected by hypo-perfusion of the temporo-parietal region while frontal hypo-perfusion may be mediated by tHcy. tHcy level is an independent risk factor for rapid cognitive decline, especially in the executive function.
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: C-W
authors.initials: CW
authors.lastname: Huang
authors.forename: W-N
authors.initials: WN
authors.lastname: Chang
authors.forename: S-H
authors.initials: SH
authors.lastname: Huang
authors.forename: C-C
authors.initials: CC
authors.lastname: Lui
authors.forename: N-C
authors.initials: NC
authors.lastname: Chen
authors.forename: Y-T
authors.initials: YT
authors.lastname: Chang
authors.forename: C-C
authors.initials: CC
authors.lastname: Lee
authors.forename: C-C
authors.initials: CC
authors.lastname: Chang
authors.forename: A Y W
authors.initials: AY
authors.lastname: Chang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000150:complications / Q000523:psychology*; D001921:Brain / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003072:Cognition Disorders / Q000097:blood* / Q000209:etiology / Q000523:psychology*; D018450:Disease Progression; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010477:Perfusion; D012307:Risk Factors; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D006710:Homocysteine
keywords: Alzheimer's disease; cortical perfusion; homocysteine; longitudinal decline; single photon emission computed tomography