A clilical correlative study of hippocampal and entorhnal cortex volume measured with MRI and mild cognitive impairment

Abstract

Objective To investigate the correlation and influencing factors between mild cognitive impairment （MCI） and the changes of hippocampal and entorhinal cortex volume and to evaluate the value of using MRI volumetric measurement of hippocampus and entorhinal cortex to identify MCI and normal cognition （NC）. Methods Twenty-one subjects selected from physical examinations were divided into an MCI group and 18 subjects were divided into an NC group. The general assessment, laboratory tests and neuropsychological scale evaluation were conducted. The MRI volumetric measurement of hippocampus and entorhinal cortex was used and its correlation with memory function was analyzed, The specificity and sensibility of diagnosing MCI of hippocampal and entorhinal cortex volume were analyzed by non-conditional Logistic regression. The influencing factors of hippocampal and entorhinal cortex volume were analyzed by multiple linear regressions. Results The hippocampal and entorhinal cortex volume in subjects with MCI was 6. 19 ± 0. 74 and 2.66 ± 0. 17 cm^3, respectively; they were significantly smaller than 6.80 ±0.79 and 3.03 ±0. 12 cm^3 in the NC group （P 〈0.05）. The hippocampal volume was significantly correlated with the entorhinal cortex volume （r = 0. 566, P 〈0. 001 ）; the hippocampal volume was significantly correlated with the total score of Clinical Memory Scale （r = 0. 430, P = 0. 04）, and the entorhinal cortex volume was significantly correlated with the total score of Clinical Memory Scale （r =0.722, P 〈0. 001）. The specificity and sensitivity of using hippocampal volume to differentiate MCI and NC were 66.7% and 76.2%, respectively. The specificity and sensitivity of using entorhinal cortex volume to differentiate MCI and NC were 88.9% and 90. 5%, respectively. In addition, There was a negative correlation between the hippocampal volume and 2 h postprandial blood glucose （P 〈 0.05）, systolic blood pressure （P 〈 0.05 ）, diastolic blood pressure （P 〈 0.05 ）, and plasma total cholesterol levels （P 〈0.01）, while the entorhinal cortex volume was not affected by the above factors. Conelusiom The atrophy of entorhinal cortex and hippocampal volume are closely associated with the memory disorders. The entorhinal cortex and hippocampal volume measured by MRI have some values for the identification of MCI and NC, and the specificity and sensitivity of entorhinal cortex volume are superior to hippocampal volume. The increased blood pressure, blood glucose, and serum lipid levels may accelerate the transformation of MCI to Alzheimer＇s disease by affecting the hippocampal volume. Key words: Cognition disorders; Hippocampus; Entorhinal cortex; Atrophy; Magnetic resonance imaging