采用基于体素的形态测量学方法评价维持性血液透析患者脑体积的变化

Voxel-based morphometry study of brain volume changes in patients with maintaining hemodialysis

目的采用基于体素的形态测量学（VBM）方法评价维持性血液透析患者脑灰、白质体积的变化，并探讨其与患者临床认知功能的相关性。方法2012年10月至2013年12月收集42例行规律性血液透析患者（患者组）与41名年龄、性别相匹配的健康志愿者（正常对照组），进行简易精神状态量表（MMsE）评分及3．0TMRI扫描。患者组和正常对照组的全脑高分辨率T1WI采用统计参数图（SPM）8软件包进行VBM分析，采用功能神经图像分析软件包（AFNi）中的蒙特卡洛模拟方法（AlphaSim方法）进行簇水平上的多重比较校正；采用独立样本t检验比较患者组和正常对照组之间脑灰、白质体积的差别。提取组间脑体积改变区域的体素值，并与透析时长、临床实验室检查指标进行逐步多元回归分析，与神经精神测试量表评分进行Spearman相关性分析。结果在右侧壳核、左侧壳核以及左侧岛叶，患者组较对照组相比，灰质体积的减少差异有统计学意义（体素数目分别为455、561、162，t值分别为-9．5681、-5．9516、-5．7185，P值均〈0．001；AlphaSim多重校正后）；右侧壳核及左侧壳核灰质体积改变值分别为（0．53±0．12）、（0．48±0．12）mm2，与透析时长[19．0（1．5—114．0）个月]呈负相关（r值分别为-0．330、-0．307，P值均〈0．05）；MMSE评分患者组[29（21—30）分】与对照组[30（28～30）分]间差异具有统计学意义（z=-30．58，P〈0．01）；左侧岛叶灰质减少体积[（0．39±0．12）mm2]与MMSE评分呈正相关（r=0．320，P〈0．05）。结论维持性血液透析患者脑体积的改变主要为灰质萎缩，并伴有认知功能下降，而透析时长则可能是其中一个重要危险因素。

Objective To detect the volume changes of cerebral gray and white matter in patients with maintaining hemodialysis using voxel-based morphometry（VBM） and to correlate these changes with cognitive function. Methods Forty-two patients with maintaining hemodialysis and 41 age and sex matched normal subjects were recruited in this study. MMSE was obtained to evaluate their neuropsychiatric conditions. Whole brain high-resolution T1WI was performed on 3.0 T MR scanner in both patients and normal controls. The data were analyzed by VBM based on SPM8, using analysis of functional neuroimages （AFNI） software package with the Monte Carlo simulation method（AlphaSim method） for multiple cluster level comparisons correction. Independent sample t test analysis was used to compare the volume of gray and white matter between the patients and normal controls. In addition, Stepwise multiple linear regression analysis was performed to explore the correlation between the voxel value of cerebral volume changes area and dialysis duration and clinical laboratory examination, and Spearman correlation analysis was used for the correlation between the left insula voxel values and neuropsychological test scores. Results Compared with normal controls, patients showed significantly decreased volume in the grey matter of the right putamen, the left putamen, the left insula （numbers of voxel in clusters were 455, 561, 162, t= - 9.5681, - 5.9516,- 5.7185, P〈0.001, AlphaSim-corrected）. There was negative correlation between decreased grey matter volume of the right putamen[（0.53 ±0.12）mm3]and the left putamen[（0.48 ± 0.12）mm3] and dialysis duration [19.0（1.5-114.0）months] （r=- 0.330, - 0.307,P〈0.05）. MMSE score of patients[29（21-30）score] was significantly lower than normal controls[30（28- 30）score] （Z=- 30.58, P〈0.01）. Decreased grey matter volume of the left insula [（0.39± 0.12） mm3] was positively correlated with MMSE（r=0.320, P〈0.05）. Conclusions The patients with maintaining hemodialysis show grey matter atrophy which is associated with neurocognitive dysfunction. Dialysis duration may be an important risk factor for decreased gray matter in patients with maintaining hemodialysis.