OBJECTIVETo investigate whether DTI abnormalities in patients with nondemented subcortical ischemic vascular disease (SIVD) are correlated to general cognitive function and executive function independent of conventional MRI parameters.

METHODSSixty-six SIVD patients including 30 with cognitive impairment without dementia (VCIND) and 36 with normal cognition (NCI) underwent DTI and cognitive assessment of the general cognitive function and executive function. Conventional MRI parameters and DTI parameters were measured within the white matter lesions (WMLs), normal-appearing white matter (NAWM) and normal-appearing gray matter (NAGM). The independent predictors of general cognitive function and executive function in SIVD patients was analyzed.

RESULTSNCI and VCIND patients showed significant differences in the periventricular WMLs, ADC valus in NAWM and WMLs of the centrum semiovale, and FA values in NAWM of the anterior periventricular. Except for ADC values of the caudate nucleus, ADC and FA values in the subcortical NAGM showed significant difference between the two groups. After controlling for age and education, PVLs and ADC values in the WMLs and NAWM of the centrum semiovale and putamen, and FA values in the anterior periventricular NAWM, WMLs and putamen showed significant correlations to MMSE; the number of lacunar infarcts, ADC values in posterior periventricular NAWM and caudate nucleus, and FA values in anterior periventricular NAWM and thalamus showed significant correlations to CDT. Multivariate analysis showed independent correlations of the ADC values in WMLs and NAWM of the centrum semiovale to MMSE, and demonstarted correlations of the ADC values of the caudate nucleus and number of lacunar infarcts to CDT.

CONCLUSIONIn nondemented SIVD subjects, the integrity of the white matter in the centrum semiovale strongly correlates to the general cognition, and the microstructural damage of the caudate nucleus head predicts executive function impairment independent of other MRI variables.