A diffusion tensor imaging study of white matter lesion in amnesic mild cognitive impairment

Objective Diffusion tensor imaging (DTI) technique with voxel ⁃ based analysis was applied to analyze the differences of whole⁃brain fractional anisotropy (FA) in an attempt to find out the characteristic changes of white matter in amnesic mild cognitive impairment (aMCI) patients. Methods According to the diagnostic criteria of aMCI and individual neuropsychological tests (verbal memory, similarity, perceptive, connection A, graphics memory, etc.), 16 aMCI patients received brain DTI and voxel⁃ based analysis were compared with the normal cognitive (NC) function subjects (control group) by differences of whole ⁃ brain FA value. Results 1) The overall rating of Mini⁃ Mental State Examination (MMSE) in the control group was 28.69 ± 1.03, higher than 27.50 ± 1.65 of the aMCI group (t = 1.278, P = 0.035). 2) The overall rating of Montreal Cognitive Assessment (MoCA) in the control group was 25.85 ± 1.52, higher than 22.50 ± 1.91 of the aMCI group (t = 0.900, P = 0.000). 3) The number of Verbal Fluency in control group was 19.08 ± 4.92, which was more than 15.14 ± 4.66 of the aMCI group (t = 0.012，P = 0.043). 4) The scores of vocabulary memory, delayed vocabulary recall, word recognition, graphic recall were 5.54 ± 0.88, 5.15 ± 1.77, 9.15 ± 1.07 and 14.69 ± 2.25, respectively, higher than those of the aMCI group 3.98 ± 1.07, 2.14 ± 1.23, 7.00 ± 2.04 and 10.57 ± 2.31 (P = 0.000, for all). 5) The FA value in the left middle frontal gyrus and right middle frontal gyrus white matter of the aMCI group was significantly lower than that of the control group. The difference was statistically significant (P < 0.001, for all). Conclusion White matter lesion (WML) of frontal lobe may be involved in the early pathophysiological processes of aMCI, and may be a new evidence for the early non⁃invasive diagnosis of aMCI. DOI：10.3969/j.issn.1672-6731.2010.02.02