ABSTRACT
OBJECTIVES: The hippocampal atrophy has been known to be an important biological marker for the early diagnosis of mild cognitive impairment (MCI). The aims of this study are to disclose the differerence in the interuncal distance (IUD) between MCI, dementia of the Alzheimer's type (DAT) and healthy aged controls, and to identify the affecting factors. METHODS: In transaxial plane, the IUDs at the level of the suprasellar cistern on the T1-weighted images on the brain MRI were measured in patients with MCI (N=30), those with DAT (N=34), and healthy aged controls (N=20). Furthermore, demographic data about age, sex, educational level as well as cerebrovascular factors were obtained by structured interviews and medical records, and the severity of cognitive disorders were assessed using the Mini-Mental Status Examination (MMSE), the Clinical Dementia Rating (CDR) and the Global Deterioration Scale (GDS). RESULTS: 1) The mean (+/-S.D.) IUD of DAT group (26.52+/-3.37 mm) was significantly different from that of healthy aged controls (24.35+/-2.91 mm)(p=0.044). However, there were no significant differences between IUD of MCI group (25.60+/-2.66 mm) and that of DAT group (p=0.483) as well as that of healthy aged controls and that of MCI group (p=0.363). 2) Variables such as age, sex, educational level, cerebrovascular risk factors and severity of cognitive disorder were not related to the IUD. CONCLUSIONS: The measurement of IUD on the brain MRI did not seem to be a helpful biological marker for the early detection of MCI in clinical practice.