A multi-parametric MRI study on changes in the structure, function, and connectivity of thalamic subregions and their relationship with cognitive impairment in patients with subcortical ischemic vascular disease.

INTRODUCTION

Prior researches have reported abnormal changes of thalamus in patients with subcortical ischemic vascular disease (SIVD), which was usually analyzed as a whole. However, it was currently unclear whether the structure, function and connectivity of thalamic subregions were differentially affected by this disease and affected different cognitive functions.

METHODS

This study recruited 30 SIVD patients with cognitive impairment (SIVD-CI), 30 SIVD patients with cognitive unimpaired (SIVD-CU) and 32 normal controls. Then we compared the volume, local brain activity, structural connectivity and functional connectivity (FC) of thalamic subregions among three groups using multi-parameter MRI images. Finally, this study analyzed the relationship between these significant values and cognitive performance.

RESULTS

In the SIVD-CI group, the weakened FC between temporal thalamus and frontal cortex, as well as the enhanced FC between temporal thalamus and motor cortex, were significantly correlated with executive impairment; the weakened structural connectivity between the thalamic subregions (pre-frontal thalamus, temporal thalamus and pre-motor thalamus) and the temporal and frontal cortices were significantly related to the declined auditory and working memory (P < 0.05). Moreover, patients in the SIVD-CU group showed no abnormalities in FC, but exhibited a similar pattern of structural connectivity injury to the SIVD-CI group, which was relatively severer. Unexpectedly, there were no significant differences in the volume and local brain activity of all thalamic subregions among the three groups.

CONCLUSIONS

The functional and structural connectivity damages between the specific thalamic subregions and the specific cortices were correlated with the specific cognitive impairment in SIVD patients.