Discordance in the anatomical locations between morphological and perfusion changes occurring with the progression of Alzheimer’s disease

Objective The aim of this study was to clarify the difference between the morphological and perfusion changes occurring with the progression of Alzheimer’s disease (AD). Methods The study focused on 37 patients who were clinically diagnosed with AD and were examined by both MRI and perfusion SPECT twice during a 1- to 2-year clinical observation period. Twenty-four of the 37 patients showed a progression of cognitive deterioration during the 1.2(±0.4)-year period of clinical observation (rapidly progressing group: initial mean MMSE score = 23.3; second mean MMSE score = 20.2), while 13 patients showed no apparent progression of cognitive deterioration (slowly progressing group: initial mean MMSE score = 21.2; second mean MMSE score = 22.2). The morphological changes were evaluated using a voxel-based morphometric technique with segmented MRI images. Cerebral perfusion was measured by Tc-99m ECD SPECT. Data analysis was performed by SPM on a MATLAB work space (2007.a). Results There was no significant difference in either the perfusion or gray matter density between the rapidly progressing and slowly progressing groups at the initial examination. The rapidly progressing group showed an interval decrease of perfusion in the bilateral parieto-occipital cortex and a decrease of gray matter density in the bilateral temporal and cingulate cortex. The slowly progressing group did not show a significant interval change in either the cerebral perfusion or gray matter density. Conclusions These results suggest that rapid symptomatic progression in AD patients accompanies rapid progression of both morphological and perfusion changes, although the regions of the changes differ between them.