Verbal or Visual Memory Score and Regional Cerebral Blood Flow in Alzheimer Disease

Abstract

Objective: Among many cognitive function deficits, memory impairment is an initial and cardinal symptom in Alzheimer disease (AD). In most cases, verbal and visual memory scores correlate highly, but in some cases the deficit of verbal or visual memory is very different from that of the other memory. In this study, we examined the neural substrates of verbal and visual memory in patients with AD.

Methods: One hundred eighty-eight consecutive patients with AD were recruited from outpatient units. Verbal and visual memory scores were evaluated using the Wechsler Memory Scale - revised. The patients underwent brain SPECT with ^99mTc-ethylcysteinate dimer.

Results: After removing the effects of age, sex, education, and Mini-Mental State Examination scores, correlation analysis showed a significant correlation of verbal memory scores to regional cerebral blood flow (rCBF) in the bilateral cingulate gyrus and left precuneus. Similarly, a significant correlation of visual memory scores to rCBF was found in the right precuneus and right cingulate gyrus.

Conclusion: The posterior medial cortices (PMC) are very important areas in episodic memory among patients with mild AD. Verbal memory is more closely related to the both sides of the PMC, while visual memory is more closely related to the right PMC.

Keywords: Alzheimer disease; Cerebral blood flow; Memory; Verbal memory; Visual memory.

Fig. 1.

a The Statistical Parametric Mapping (SPM) (t) map of significant correlations between regional cerebral blood flow (rCBF) and verbal memory scores among Alzheimer disease (AD) patients after removing the effects of age, sex, and education. b The SPM (t) map of significant correlations between rCBF and verbal memory scores among AD patients after removing the effects of age, sex, education, and MMSE scores. c The SPM (t) map of significant correlations between rCBF and visual memory scores among AD patients after removing the effects of age, sex, and education. d The SPM (t) map of significant correlations between rCBF and visual memory scores among AD patients after removing the effects of age, sex, education, and MMSE scores. a–d Three-way glass view of the area of significant correlation. Upper right, coronal; upper left, sagittal; lower, transverse.