École d'orthophonie et d'audiologie (A.O.G., A.B., K.M), Université de Montréal, Quebec, Canada.
Centre de recherche du Centre intégré universitaire de santé et de services sociaux du Nord-de-l'île-de-Montréal, Quebec, Canada (A.O.G., S.M.B., A.B., A.D., K.M.).
Stroke. 2024 Nov;55(11):2643-2651. doi: 10.1161/STROKEAHA.124.047229. Epub 2024 Oct 28.
Poststroke aphasia (PSA) recovery shows high variability across individuals and at different time points. Although diffusion biomarkers from the ventral and dorsal streams have demonstrated strong predictive power for language outcomes, it is still unclear how these biomarkers relate to the various stages of PSA recovery. In this study, we aim to compare diffusion metrics and language measures as predictors of language recovery in a longitudinal cohort of participants with PSA.
Participants were recruited at a stroke unit at the emergency room, and underwent diffusion magnetic resonance imaging scanning and language assessment within 3 days (acute phase) after stroke, with behavioral follow-ups at subacute (10±3 days) and chronic phases (>6 months). We conducted regression analyses on language performance (cross-sectional), Δscores between all time points (acute-subacute, subacute-chronic, acute-chronic), and relative Δscores between all time points (Δscore/language baseline score), with acute diffusion metrics from language-related white matter tracts, lesion size, language baseline scores, and demographic data as predictors.
Thirty-nine participants presenting PSA were recruited, and 24 participants (mean age, 73 years; 8 women) completed the 3-time point assessment in total. The best prediction model of performance scores used axial diffusivity from the left arcuate fasciculus in both the subacute (=0.785) and chronic stages (=0.626). Moreover, the prediction of ∆scores depended on axial diffusivity from the left inferior frontal-occipital fasciculus in the subacute stage (=0.5) and depended additionally on axial diffusivity from the right inferior frontal-occipital fasciculus in the chronic stage (=0.68). The prediction of mediation analyses showed that the lesion load of the left arcuate fasciculus mediated the relationship between axial diffusivity from the left arcuate fasciculus and chronic language performance.
Language performance at subacute and chronic time points could be predicted by the integrity of the left arcuate fasciculus, whereas Δscores in the subacute and chronic phases depended on the left inferior frontal-occipital fasciculus, showing a dissociation of the white matter pathways about language outcomes. These results suggest a functional differentiation of the dual-stream components in PSA recovery.
脑卒中后失语症（PSA）的恢复在个体之间和不同时间点表现出高度的可变性。尽管来自腹侧和背侧流的扩散生物标志物已经证明了对语言结果的强大预测能力，但这些生物标志物与 PSA 恢复的各个阶段之间的关系仍不清楚。在这项研究中，我们旨在比较扩散指标和语言测量指标，以预测 PSA 患者的纵向队列中的语言恢复。
参与者在急诊室的脑卒中病房招募，并在脑卒中后 3 天内（急性期）进行扩散磁共振成像扫描和语言评估，并在亚急性期（10±3 天）和慢性期（>6 个月）进行行为随访。我们对语言表现（横截面）、所有时间点之间的Δ分数（急性期-亚急性期、亚急性期-慢性期、急性期-慢性期）以及所有时间点之间的相对Δ分数（Δ分数/语言基线分数）进行回归分析，以急性扩散指标、语言相关白质束、病变大小、语言基线分数和人口统计学数据作为预测指标。
共招募了 39 名 PSA 患者，其中 24 名患者（平均年龄 73 岁，8 名女性）总共完成了 3 次时间点评估。在亚急性期（=0.785）和慢性期（=0.626），表现分数的最佳预测模型使用左侧弓状束的轴向弥散度。此外，Δ分数的预测取决于亚急性期左侧额枕下束的轴向弥散度（=0.5），并且还取决于慢性期右侧额枕下束的轴向弥散度（=0.68）。中介分析的预测表明，左侧弓状束的病变负荷介导了左侧弓状束的轴向弥散度与慢性语言表现之间的关系。
亚急性期和慢性期的语言表现可以通过左侧弓状束的完整性来预测，而亚急性期和慢性期的Δ分数取决于左侧额枕下束，显示出语言结果的白质通路的分离。这些结果表明 PSA 恢复中双重流成分的功能分化。
