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

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. (authors)