White matter change in diffusion tensor imaging of amnestic mild cognitive impairment / 中华神经科杂志

ABSTRACT

Objective To investigate the features of white matter impairment and its relationship with cognition in patients with amnestic mild cognitive impairment (aMCI).Methods Eighty-three cases of aMCI and 85 normal aging volunteers were scanned with diffusion tensor imaging (DTI) using MR system.All subjects completed the neuropsychological battery.We analyzed the differences between two groups using tract-based spatial statistics and the association between regions in difference and cognition using correlation analysis.Results There were significant differences between aMCI and normal control in the neuropsychological battery including the Mini-Mental State Examination(26.2 ± 2.6 vs 28.3 ± 1.3,F =43.224,P =0.000),Mattis Dementia Rating Scale-2 (131.4 ± 6.9 vs 138.0 ± 3.5,F =62.308,P =0.000),Auditory Verbal Learning Test-delayed recall(2.4 ± 1.6 vs 7.5 ± 2.0,F =324.018,P =0.000),Boston Naming Test(8.7 ± 1.4 vs 9.2 ± 1.0,F =6.821,P =0.010),Rey-Osterrich Complex Figure Test (12.1 ± 7.3 vs 18.5 ± 6.1,F =40.674,P =0.000),Symbol Digit Modulation Test (30.0 ± 10.1 vs 38.6 ± 9.8,F =30.786,P =0.000),Trail-Making Test Part B ((256.8 ± 124.5) s vs (178.1 ± 59.0) s,F =27.601,P =0.000).Significantly higher diffusivity indexes and radial diffusivity were also found in aMCI subjects compared to healthy elders in the parahippocampal,superior longitudinal fasciculus,inferior longitudinal fasciculus,superior fronto-occipital fasciculus,inferior fronto-occipital fasciculus,unciform fasciculus,corticospinal tract,corpus callosum,cingulum,corona radiate.We also found that axial diffusivity was significantly increased in the parahippocampal,superior longitudinal fasciculus,inferior longitudinal fasciculus,superior fronto-occipital fasciculus,inferior fronto-occipital fasciculus,unciform fasciculus,corticospinal tract and corpus callosum,whereas fractional anisotropy changes were not observed in aMCI.Diffusivity indexes values in bilateral frontal lobe (left r =0.67 ; right r =0.70),left cingulum (r =0.63),parietal white matter (r =0.69) and radial diffusivity values in left parietal (r =0.68) were significantly related to Trail Making Test A among aMCI (all P ＜ 0.05).Conclusions In aMCI patients,there was a wide range of white matter damage,with no brain region-specific.Executive function deficit was related to the white matter impairment in bilateral frontal lobe,left cingulate and parietal lobe.The specificity and sensitivity of four DTI parameters fordetecting white matter lesions are variant.Trial registration Clinical Research Center of Jiangsu Province (BL2013025)