EFFECTS ON VENTRICULAR ENLARGEMENT WHEN COMPARING COGNITIVELY NORMAL ELDERLY AND PEOPLE WITH AMNESTIC AND NONAMNESTIC MILD COGNITIVE IMPAIRMENT

Abstract

Background: Alzheimer’s Disease Assessment Scale cognitive subscale (ADAS-cog) is widely used for the assessment of severity and/or therapy evaluation of Alzheimer’s disease (AD). But little is known concerning the spatial correlation of the brain regions to the performance in ADAScog. By using a newly developed 3-D statistical imaging software, Correlation Imaging Plots (CIPs), which can visualize the spatial correlation of regional cerebral blood flow (rCBF) with any continuous parameters, we tried to elucidate the relationship between rCBF and the score of Japanese version of ADAS-cog in AD patients. Methods: The present study was based on 55 patients with early stage of AD patients, 51 mild cognitive impairment (MCI) patients and 32 age-matched normal controls. All of them were right handed and those with cerebral organic lesions were excluded. They underwent 99mTc-ECD SPECT and ADAS-cog. We analyzed those data by using and CIPs program and statistical parametrical mapping (SPM) version 8 for comparison. In the SPM analysis, patients were classified into two groups according to the score of ADAS-cog: those with high performance (&x 10) and those with low performance (<10). Results: The ADAS-cog total score correlated with the hypoperfusion in bilateral posterior cingulate cortices, precuneus and superior and inferior parietal lobules in CIPs analysis. Among the ADAS-cog subscales, the orientation, recall and recognition scores correlated with rCBF in the similar regions. Construction score correlated with rCBF in left temporoparietal cortex. Only a small difference was observed in the same areas between the high and low perforamce groups in SPM analysis. Conclusions: Our results indicate that ADAS-cog reflects the bilateral parietal function which is predominantly associated with recall and orientation ability. These brain regions were supposed to be crucial for short-term memory.