Diffusion tensor imaging of executive dysfunction in the patients with leukoaraiosis / 中华老年医学杂志

ABSTRACT

Objective To determine the relationship between characteristic damages in white matter and its executive dysfunction by magnetic resonance diffusion tensor imaging (DTI) in the patients with leukoaraiosis (LA). Methods A total of 23 patients with LA and 19 age,sex and education-matched healthy people as control were enrolled.Montreal cognitive assessment (MoCA),Stroop test,trail making test (TMT),digit-symbol test(DST),verbal fluence (VF) were applied to assess cognitive and executive functions.Fractional anisotropy (FA),apparent diffusion coefficient (ADC) and mean diffusivity (MD) in white matter lesion (WML) and normal appearing white matter (NAWM) were measured in LA group,the bilateral centrum semiovale,anterior and posterior periventricular white matter in control group were measured by DTI. The white matter DTI parameters were compared between the groups, the relationship between DTI parameters and executive function was investigated in LA group. Results In LA patients,distinct executive dysfunction were found.The scores of Stroop B [(69.4± 13.4) vs.(43.3 ± 5.0),t =8.03,P＜0.05)],Stroop C [(141.4±42.1) vs.(65.4±10.3),t=7.66,P＜0.05)]and Stroop C B[ (72.0±41.4) vs.(22.1±9.6),t=5.13,P＜0.05)],TMT-A[(73.2±15.3)vs.(31.2±7.2),t 10.97,P＜0.05) ],TMTB[(125.6±18.0) vs.(81.6±5.9),t=10.22,P＜0.05) ] andDST[ (24.8±5.6 )vs.(36.8±5.1),t=7.19,P＜0.05) ] were inferior in LA group to control group.The values of FA in centrum semiovale [(0.2±0.1) vs.(0.4±0.1) and (0.4±0.1),F =45.08,P＜0.05)],anterior periventricular white matter [(0.2±0.0) vs.(0.4±0.1) and (0.4±0.1),F =70.11,P＜0.05)] and posterior perivcntricular white matter[ (0.3±0.1) vs.(0.4±0.1) and (0.4±0.1),F=8.54,P＜0.05) ]of WML were reduced as compared with those of NAWM and control group.The values of ADC(×10- 3mm2/s) in the above three regions of WML [(1.2±0.2) vs.(0.8±0.1) and (0.8±0.1),F=46.77,P＜0.05)],[(1.2±0.3) vs.(0.8±0.0) and (0.8±0.1),F=68.22,P＜0.05)]and [(1.4±0.3) vs.(0.8±0.0) and (0.9±0.1),F=17.08,P＜0.05) ] were elevated,as compared with those of NAWM and control group,and the values of MD ( × 10-5 mm2/s) in the three regions of WML[ (127.8±14.5) vs. (95.3±26.4) and (100.8±9.4),F 19.72,P＜0.05) ],[(127.4±16.0) vs.(101.8±13.9) and (93.4±5.6),F=39.26,P＜0.05) ] and [(134.4±21.2)vs.(114.8=14.5) and (114.4±11.7),F=10.66,P＜0.05) ]were also increased,as compared with those of NAWM and control group.There was negative correlation of FA with Stroop C-B (r=-0.46,P＜0.05),TMT-A (r=-0.48,P＜0.05) and TMT-B (r=0.46,P＜0.05),while FA was positively related with DST test (r=0.42,P＜0.05) in anterior periventricular white matter.Conclusions DTI can detect the characteristic damages of white matter,which is strongly related with executive function impairments possibly induced by the damage of prefrontal-subcortical loop in the patients with LA.