Abstract Body: Introduction The combination of verbal and non-verbal cognitive dysfunction in post-stroke aphasia (PSA) patients may ultimately affect social interactions. However, the underlying neural mechanisms of both verbal and non-verbal cognitive impairment remain unclear. This study aimed to investigate the activity and functional abnormalities of local and remote brain regions and their relationship with cognitive behaviour, to provide more effective guidance in future clinical therapy.
Methods We recruited 46 PSA patients and 40 normal controls(NCs) matched for general characteristics in this study and evaluated their verbal and non-verbal cognitive functions. Functional magnetic resonance imaging(fMRI) was used to examine the fractional amplitude of low-frequency fluctuations(fALFF), regional homogeneity(ReHo), and functional connectivity(FC) in PSA patients. Independent two-sample t-tests were used to identify differences in these measures between two groups. Moreover, partial correlation analyses were performed to determine the correlation between FC from the affected brain regions and language and cognitive performance in PSA patients.
Results This study revealed that PSA patients presented significantly lower fALFF and ReHo values in right cerebellum superior (CRBL.Superior.R), left thalamus(THA.L), and left middle frontal gyrus(MFG.L). Moreover, the FC in the MFG.L-left inferior frontal gyrus, orbital part was significantly lower among PSA patients and was positively correlated with language and cognitive performance(p< 0.05). The CRBL. Superior. R-left caudate nucleus and right lenticular nucleus FC were also decreased and were associated with cognitive function(p< 0.05). In addition, PSA patients were further divided into fluent and nonfluent groups. The results revealed that nonfluent patients performed worse in verbal and non-verbal cognitive performance(p< 0.05) and had weaker performance in the THA.L and left supplementary motor area FC(p< 0.001).
Conclusions This study provides new evidence that abnormal neural activity and functional connectivity within specific brain regions may play crucial roles in language and cognitive processing. The underlying mechanisms of impaired linguistic function accompanied by decline in cognition may be a partial overlap between language and cognitive-related brain networks. In future, combining cognitive and linguistic functions and designing a comprehensive treatment plan will be the focus of rehabilitation.