Reduced Gray Matter Volume in Subjective Memory Impairment: A Voxel-Based Morphometric Study

초록

Background & objective: There is increasing evidence that markers for Alzheimer’s disease (AD) are common in patients with subjective memory impairment (SMI). The aim of this study was to investigate whether the subjects with SMI had less gray matter volume compared to healthy controls without memory complaints. Methods: Thirty six subjects with SMI were recruited consecutively from a memory clinic. They were 5o years or older, and scored within 1.0 SD on all subtests of the Seoul Neuropsychological Screening Battery-dementia version. They were not demented and their activities of daily livings were not impaired. We excluded the subjects with the Korean version of Geriatric Depression Scale score above 18, or with any medical, neurological or psychiatric illnesses which could result in cognitive dysfunction. And thirty three healthy control subjects without memory complaints were recruited. All subjects were scanned at 1.5-Tesla MRI scans. We used voxel-based morphometry to examine gray matter volumes between groups, controlling for age, sex, and total intracranial volumes. Results: There were no significant differences of age (64.6  7.7 years vs. 63.9  7.5 years, p=0.69) and sex (female, 81% vs. 88%, p=0.52) between the SMI and control groups. Total brain volume did not differ between the groups. Individuals with SMI had significantly decreased gray matter volumes in left precuneus, left inferior temporal and middle frontal gyri, and right superior parietal lobule compared to the control group. Conclusions: SMI was associated with lower gray matter volume in AD-vulnerable brain regions. There data supports the concept of SMI as a very early manifestation of AD prior to mild cognitive impairment.