Objective To provide an imaging reference for assessing cognitive dysfunction progression in patients with ischemic white matter lesion (IWML).
Methods Patients with IWML admitted to Beijing Tiantan Hospital, Capital Medical University from January 2018 to December 2021 were retrospectively included. They were divided into two groups according to the results of the cognitive function assessment: the non-dementia vascular cognitive impairment (VCIND) group and the vascular dementia (VaD) group. Patients with normal cognitive function and brain MRI results were enrolled in the normal control (NC) group at the same time. All patients underwent resting state functional MRI examination and attention function tests, including Stroop color-word interference B test (Stroop B), Stroop color-word interference C test (Stroop C), trail making test A (TMT-A), and symbol digit modalities test (SDMT). The left frontoparietal network, right frontoparietal network, primary visual network, secondary visual network, and dorsal attention network were selected by independent component analysis. Nine major regions were chosen as regions of interest, and the Z value of each brain region was extracted as the functional connectivity (FC) value of the pairwise brain interval. The differences in FC among the three groups were analyzed, and the correlation between altered FC and attention function scores in VCIND and VaD groups was further investigated.
Results Among 60 eligible patients, 29 (48.3%) being male. There were 24 cases in the NC group, 19 cases in the VCIND group, and 17 cases in the VaD group. The results suggested that compared with the NC group, the VCIND group had higher scores on the Stroop B (P<0.01) and TMT-A (P=0.01), and the SDMT scores were lower (P=0.01). In the VaD group, patients had higher scores on the Stroop B, Stroop C, and TMT-A (P<0.01), and had lower scores on the SDMT (P<0.01). Compared with the VCIND group, the VaD group had higher scores on the Stroop B (P<0.01), Stroop C (P<0.01), and TMT-A (P=0.01) and had lower SDMT scores (P<0.01). The FC analysis results showed that compared with the NC group, the FC between the right dorsolateral prefrontal cortex and the left superior parietal lobule (P=0.01), and the right dorsolateral prefrontal cortex and cuneus (P=0.04) were increased in the VCIND group. Compared with the VCIND group, the FC between the right dorsolateral prefrontal cortex and cuneus (P=0.02) was increased in the VaD group. The FC between the right dorsolateral prefrontal cortex and the left superior parietal lobule was negatively correlated with the Stroop C score (r=－0.365, P=0.04), while the FC between the other brain regions was not significantly correlated with other attention function scores.
Conclusions With the decline of cognitive, the FC between the executive network and the dorsal attention network, as well as the primary visual network increased in IWML patients, and the FC changes in some brain regions were associated with worse attention function.
