Alterations of Functional Connectivity in Stroke Patients With Basal Ganglia Damage and Cognitive Impairment

Abstract

Background: Stroke with basal ganglia damage (SBG) is a neurological disorder characterized by cognitive impairment. The neurobiological mechanism of cognitive impairment in stroke patients with basal ganglia damage (SBG patients) remains unclear. This study aimed to explore the underlying neurobiological mechanism of cognitive impairment in SBG patients using resting-state functional magnetic resonance imaging (rs-fMRI). Methods: The differences in functional connectivity (FC) between 14 SBG patients (average age: 61.00 ± 7.45 years) and 21 healthy controls (HC) (average age: 60.67 ± 6.95 years) were examined using voxel-mirrored homotopic connectivity (VMHC) and degree centrality (DC). Moreover, we compared the cognitive functions of SBG patients with HC using the Chinese Revised Wechsler Adult Intelligence Scale (WAIS-RC) and Wechsler Memory Scale (WMS). Results: Full-scale intelligence quotient (FIQ) (t = 2.810, p < 0.010) and memory quotient (MQ) (t = 2.920, p < 0.010) scores of SBG patients were significantly lower than those of HC. Compared with HC, significantly decreased VMHC values in the bilateral angular gyrus, supramarginal gyrus, inferior frontal gyrus, middle temporal gyrus, hippocampus, precuneus, precentral gyrus, and middle occipital gyrus and decreased DC values in the right supramarginal gyrus, bilateral angular gyrus, and right postcentral gyrus were observed in SBG patients. Moreover, the VMHC values in the angular gyrus, inferior frontal gyrus, supramarginal gyrus, and middle temporal gyrus and the DC values in the right supramarginal gyrus were significantly correlated with cognitive functions in all participants. Conclusion: Our findings may provide a neural basis for cognitive impairments in SBG patients. Furthermore, local abnormalities of functional networks and interhemispheric interaction deficits may provide new ideas and insights for understanding and treating SBG patients' cognitive impairments.

Keywords: basal ganglia damage; cognitive function; degree centrality (DC); functional magnetic resonance imaging (fMRI); stroke; voxel-mirrored homotopic connectivity (VMHC).

Figure 1

The lesion overlap map of SBG patients. Warm tones represent the superposition of the patient's lesion site. SBG patients, stroke patients with basal ganglia damage; L, left; R, right.

Figure 2

The differences in brain regions in VMHC between HC and SBG patients. The comparison between the two groups was acquired by a two-sample t-test (corrected with AlphaSim for multiple comparisons: voxel-wise p < 0.001 and lesions were excluded within the mask). Decreased VMHC values in SBG patients are represented by cool tones. SBG patients, stroke patients with basal ganglia damage; HC, healthy controls; VMHC, voxel-mirrored homotopic connectivity; L, left; R, right.

Figure 3

The differences in brain regions in DC between HC and SBG patients. The comparison between the two groups was obtained using a two-sample t-test (corrected with AlphaSim for multiple comparisons: p < 0.001). Decreased DC values in SBG patients are represented by cool tones. SBG patients, stroke patients with basal ganglia damage; HC, healthy controls; DC, degree centrality; L, left; R, right.

Figure 4

The correlations between brain functions and cognitive functions. (A) The diagram shows that the VMHC values in the angular gyrus were associated with FIQ scores (r = 0.472, p = 0.004, d = 1.071) in all participants. (B) The diagram shows that the VMHC values in the inferior frontal gyrus were associated with FIQ scores (r = 0.496, p = 0.003, d = 1.142) in all participants. (C) The diagram shows that the VMHC values in the supramarginal gyrus were associated with FIQ scores (r = 0.498, p = 0.002, d = 1.149) in all participants. (D) The diagram shows that the VMHC values in the middle temporal gyrus were associated with MQ scores (r = 0.524, p = 0.001, d = 1.230) in all participants. (E) The diagram shows that the DC values in the right supramarginal gyrus were associated with FIQ scores (r = 0.427, p = 0.010, d = 0.944) in all participants. (F) The diagram shows that the DC values in the right supramarginal gyrus were associated with MQ scores (r = 0.428, p = 0.010, d = 0.947) in all participants. Bonferroni correction with p < 0.05 was applied. r represents the Pearson correlation; p represents the significance level; d represents the effect size of the test. The red dots represent SBG patients, and the black dots represent HC. SBG patients, stroke patients with basal ganglia damage; HC, healthy controls; MQ, memory quotient; FIQ, full-scale intelligence quotient; VMHC, voxel-mirrored homotopic connectivity; DC, degree centrality.