Background and Purpose-Silent lacunar infarct (SLI) is a risk factor for dementia. This study investigated the white matter integrity abnormality and its relationship to the cognition impairments in SLI patients. Methods-Between 27 patients with SLI in basal ganglia and 30 healthy controls, we assessed the difference in a batter of neuropsychological tests and in white matter integrity measurements, fractional anisotropy, and mean diffusivity, using tract-based spatial statistics. Results-Compared with healthy controls, SLI patients performed worse in general mental status, memory, executive function, and language ability. They also had reduced fractional anisotropy and increase mean diffusivity in brain regions such as the body and genu of corpus callosum, the forceps minor, the bilateral superior and bilateral anterior corona radiate, and the left external capsule. Furthermore, we found that in SLI patients, fractional anisotropy measure in left external capsule was positively correlated to the performance in memory and language ability. Conclusions-SLI in basal ganglia leads to local and remote white matter integrity damages and to the cognition impairments.

Silent lacunar infarcts, which are present in over 20% of healthy elderly individuals, are associated with subtle deficits in cognitive functions. However, it remains largely unclear how these silent brain infarcts lead to cognitive deficits and even dementia. Here, we used diffusion tensor imaging tractography and graph theory to examine the topological organization of white matter networks in 27 patients with silent lacunar infarcts in the basal ganglia territory and 30 healthy controls. A whole-brain white matter network was constructed for each subject, where the graph nodes represented brain regions and the edges represented interregional white matter tracts. Compared with the controls, the patients exhibited a significant reduction in local efficiency and global efficiency. In addition, a total of eighteen brain regions showed significantly reduced nodal efficiency in patients. Intriguingly, nodal efficiencybehavior associations were significantly different between the two groups. The present findings provide new aspects into our understanding of silent infarcts that even small lesions in subcortical brain regions may affect large-scale cortical white matter network, as such may be the link between subcortical silent infarcts and the associated cognitive impairments. Our findings highlight the need for network-level neuroimaging assessment and more medical care for individuals with silent subcortical infarcts.