Dynamics and concordance alterations of intrinsic brain activity indices in stroke-induced Broca's aphasia varies based on first language: A resting-state fMRI analysis.

Objective: This study aimed to investigate the changes in intrinsic brain activity (IBA) among individuals with Broca aphasia (BA) after a stroke.

Methods: We collected information from 60 participants. The participants were categorized into four groups according to language (Uyghur and Chinese) and BA status (BA and healthy): Uyghur aphasia patients (UA), Uyghur healthy control subjects (UH), Chinese aphasia patients (CA), and Chinese healthy control subjects (CH). Each group comprised 15 individuals. The shifting dynamics and concordance of regional IBA indices were examined via sliding time-window analysis. A two-way analysis of variance (ANOVA) was conducted with the IBA indices to test for regions with interactions between language and BA status. Partial correlation analysis was employed to evaluate the relationships between various indices and language behaviors.

Results: Participants with head motion exceeding 3 mm translation or 3° rotation were excluded, leaving 9, 12, 13, and 15 participants in the UA, CA, UH, and CH groups, respectively. Seven IBA indices were activated in 16 brain regions in the four groups. In detail, two-way ANOVA revealed a significant interaction between language and BA status in four IBA dynamic indices (amplitude of low-frequency fluctuations (ALFF), Regional homogeneity (ReHo), degree centrality (DC), and functional connectivity (FC)) in 11 brain regions (P < 0.000). For the other three dynamic indices (fractional amplitude of low-frequency fluctuation (fALFF), Voxel-mirrored homotopic connectivity (VMHC), and Global signal connectivity (GSCorr)), no interaction was observed among the four groups. However, the main effect analysis of the BA state demonstrated significant differences across a total of six brain regions (P < 0.000). The concordance alterations in fALFF, ReHo, VMHC, DC, and GSCorr in the right calcarine fissure and the surrounding cortex were significantly lower in CA than in CH (P = 0.000), significantly higher in UA than in CA (P = 0.025), and significantly lower in UH than CH (P = 0.000).

Conclusion: In conclusion, alterations in IBA dynamics and concordance were observed in individuals from UA, UH, CA, and CH. These findings suggest that the IBA dynamic index varies across brain regions of BA patients with different local languages, providing a novel perspective for investigating brain alterations by analyzing temporal dynamics using rs-fMRI data.