Abnormal resting-state neural activities of language and non-language cognitive function impairments in stroke patients with aphasia: A cross-sectional study

Abstract

Objective

Language impairments may mask non-language cognitive deficits in post-stroke aphasia (PSA) patients. Moreover, the underlying neural mechanisms of both language and non-language cognitive impairment remain unclear. This study aimed to investigate the activities and functional abnormalities of local and remote brain regions and their relationship with cognitive function in PSA patients, to provide more effective tips in future clinical therapy.

Methods

This cross-sectional study included 46 PSA patients and 40 controls, who underwent language and non-language cognitive assessments, and resting-state functional magnetic resonance imaging (rs-fMRI). We then examined the fractional amplitude of low-frequency fluctuations (fALFF), regional homogeneity (ReHo), and functional connectivity (FC) based on a modest sample size (46 PSA patients and 40 normal controls (NCs)). Independent two-sample t-tests were used to identify differences in these measures between PSA patients and NCs. Moreover, partial correlation analyses were performed to determine the correlation between FC from the affected brain regions and language, and non-language cognitive performance in PSA patients.

Results

This study revealed that both fALFF and ReHo in PSA patients presented significantly lower in the right superior cerebellum, left thalamus, and left middle frontal gyrus, along with increased values in the right superior frontal gyrus (dorsolateral part) (p < 0.05). Notably, decreased FC between the left middle frontal gyrus and orbital part of the left inferior frontal gyrus was significantly associated with both language and non-language cognitive performance (p < 0.05). In addition, PSA patients were further divided into fluent and non-fluent groups. The results revealed that non-fluent patients demonstrated worse overall cognitive functioning, accompanied by reduced FC between the left thalamus and the left supplementary motor area (p < 0.001).

Conclusion

This study provides new evidence that abnormal neural activities and functional connectivities within specific brain regions may play crucial roles in language and non-language cognitive function. The underlying mechanisms of non-language cognitive decline accompanied by impaired language function in PSA patients may be a partial overlap between language and cognitive networks. In the future, combining language and non-language functions and designing a comprehensive treatment plan will be the focus of rehabilitation.