Introduction: Though not classically a language region, the cerebellum, particularly right Crus I/II (Cereb1/2), is linked to linguistic performance in post-stroke aphasia. Neuromodulation studies also implicate this area in language, suggesting a possible therapeutic target. Prior work has often examined naming tasks, with limited data regarding other language domains. We tested whether resting state functional connectivity (FC) between the right cerebellum and traditional language regions predicts performance across a variety of behavioral measures in post-stroke aphasia. Methods: Using CONN, we computed ROI-to-ROI FC between right Cereb1/2 seeds and 46 bilateral language ROIs in chronic post-stroke aphasia patients (n=40; mean age=57.2; mean MPO=77.6). FC pairs showing significant group-level connectivity were entered into stepwise multiple linear regressions for 26 behavioral outcomes, plus two principal components (PCs) summarizing language and non-language performance. Nested Anova compared covariate-only models (age, MPO, education, lesion volume) with models adding FC. Results: Adding Cereb1/2-seeded FC significantly improved prediction for 26 of 28 outcomes (Figure 1). Naming results replicated prior findings (BNT, WAB naming/word finding), and larger adj.-R2 gains were observed in other language tasks (e.g., PALPA 8/25, nonword repetition/word reading). Cereb1/2-seeded FC also improved prediction of non-linguistic measures, like RBANS Visuospatial and Attention. Adj.-R2 gain was 0.25 for the Language PC and 0.40 for the non-language PC. Higher FC from right Cereb2 to left posterior ITG/left Cereb2 and right Cereb1 to left posterior MTG/right planum temporale consistently supported better performance (Figure 2), while higher FC from right Cereb2 to left posterior SMG/right posterior ITG and right Cereb1 to right parietal operculum predicted worse performance. Conclusion: Right Cereb1/2-seeded FC improved prediction of almost all behavioral measures beyond demographics and lesion volume. This emphasizes the cerebellum’s role not only in post-stroke language performance, but also in non-linguistic domains like attention and working memory which may support language processing and recovery. Connections between right cerebellar and bilateral temporo-parietal regions showed consistent effects on task performance; future work exploring effects of neuromodulation in these areas can provide a reliable therapeutic target for post-stroke aphasia rehabilitation.
Kropp et al. (Thu,) studied this question.