| Objective: Amnestic mild cognitive impairment(a MCI) presents with memory disturbance as the main clinical manifestation, and other cognitive domains may be affected as well. Individuals with a MCI have significantly increased risk for progressing into Alzheimer’s disease(AD). White matter injury plays an important role in a MCI. Diffusion tensor imaging(DTI) can estimate the integrity of white matter. Voxel-based analysis(VBA) is able to analyze parameters of the whole brain voxels with high objectivity and accuracy. In this paper, we used VBA of DTI data to evaluate whether white matter changes existing in a MCI patients and the correlation between white matter injury and neuropsychological scale. In order to find the characteristics and regularity of white matter microstructural changes in a MCI, and provide objective basis for early identification and monitoring progression of a MCI.Methods: 25 a MCI patients and 25 normal controls matched by age, sex and education were collected from the Department of Neurology of the First Affiliated Hospital of Dalian Medical University. Mini-mental state examination(MMSE) and Montreal cognitive assessment(Mo CA) were used to evaluate the cognitive level of all participants. DTI data was acquired on a 3.0T GE Signa MR scanner. We calculated fractional anisotropy(FA) maps with DTI studio software. The statistical analyses were carried-out using Statistical Parametric Mapping 8(SPM8) running under Mat Lab R2009 a. We performed voxel-based analysis of variance with SPM8 to acess the differences of white matter integrity between two groups using FA values as the dependent variables.In a MCI patients,a correlation was also performed between FA values and the scores of MMSE and Mo CA.Results:1. There were no demographic differences between the two groups in sex,age and education(Psex = 1, Page = 0.96, Pedu = 0.26);The scores of MMSE and Mo CA were significantly lower in a MCI group than normal group( PMMSE = 0.000, PMo CA = 0.000).2. FA was significantly lower in a MCI group than normal group in regions of bilateral inferior frontal gyrus, right precentral gyrus, right medial frontal gyrus, right precuneus, right inferior parietal lobule, left cingulate gyrusand left supramarginal gyrus(all Puncorr<0.001, KE≥50).3. FA in a MCI patients had positive correlation with scores of MMSE in regions of bilateral precentral gyrus, bilateral cerebellum posterior lobe, right superior frontal gyrus, right medial frontal gyrus, right claustrum, left inferior frontal gyrus, left middle frontal gyrus and left pontine(all Puncorr<0.001, KE≥50). FA in a MCI patients had positive correlation with scores of Mo CA in regions of specific regions bilateral precentral gyrus, right cingulate gyrus, right superior frontal gyrus, right cerebellum posterior lobe,left middle frontal gyrus, and left superior temporal gyrus(all Puncorr<0.001, KE≥50).Conclusion:1. a MCI patients have comprehensive cognitive impairment, and refer to the clinical condition between normal aging and AD. MMSE scale and Mo CA scale can can be used for analysing cognitive functions in patients with a MCI.2. a MCI patients have specific regions of white matter damage, especially in regions of bilateral inferior frontal gyrus, right precentral gyrus, right medial frontal gyrus, right precuneus, right inferior parietal lobule, left cingulate gyrusand left supramarginal gyrus. The changes of them may participate in the early stage of a MCI.3. In a MCI patients, white matter changes of some specific regions(including bilateral precentral gyrus, right cingulate gyrus, right superior frontal gyrus, left middle frontal gyrus, left superior temporal gyrus.ect) have positive correlation with cognitive impairment. White matter in these regions may be more significantly related to cognitive function.4. Voxel-based analysis of DTI can evaluate the integrity of white matter in whole brain levels. This can provide objective basis for early identification and monitoring progression of a MCI patients. |
PDF Full Text Request