title: Longitudinal evaluation of both morphologic and functional changes in the same individuals with Alzheimer's disease.
abstract: Morphologic and functional imaging studies have not always given concordant results about brain areas showing atrophic changes and reduced flow or metabolism in Alzheimer's disease (AD). The aim of this study was to determine the initial abnormality and the longitudinal changes in both morphologic and functional measurements for the same individuals with AD.
  
  
  METHODS
  We investigated 15 patients with mild AD and 25 age-matched healthy volunteers. The AD patients underwent both MRI and SPECT 3 times at intervals of approximately 1 y. The gray matter volume, as segmented from MRI, and the regional cerebral blood flow (rCBF), as measured by SPECT, of AD patients were compared with those of healthy volunteers using statistical parametric mapping, which is a voxel-based analysis in stereotactic space.
  
  
  RESULTS
  Considerable discordance between areas of regional atrophy and areas of decreased rCBF was observed. The medial temporal areas showed a faster and more extensive reduction of gray matter volume than of rCBF. In comparison with the value at the baseline study, rCBF in the posterior cingulate gyrus and precuneus and the associative parietal cortex was extensively decreased. In contrast, the extent of significant decrease in this area continued to be much narrower for gray matter volume than for rCBF, even in the follow-up studies. Frontal areas, including the anterior cingulate gyrus and the orbitofrontal areas, showed a progressive reduction in both rCBF and gray matter volume. The reduction in rCBF was in a more posterior part of the associative temporal cortex than was the reduction in gray matter volume.
  
  
  CONCLUSIONS
  These results indicate a distinct discordance between morphologic and functional changes in a longitudinal study of AD. Functional changes may be caused partly by remote effects from the morphologically involved areas with decreased connectivity and partly by a compensatory response by neuronal plasticity.
authors.affiliation: Department of Radiology, National Center Hospital for Mental, Nervous, and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo, Japan. matsudah@ncnpmusashi.gr.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kitayama
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Takashi
authors.initials: T
authors.lastname: Asada
authors.forename: Seigo
authors.initials: S
authors.lastname: Nakano
authors.forename: Shigeki
authors.initials: S
authors.lastname: Sakamoto
authors.forename: Etsuko
authors.initials: E
authors.lastname: Imabayashi
authors.forename: Asako
authors.initials: A
authors.lastname: Katoh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015899:Tomography, Emission-Computed, Single-Photon