Kropp Emerson, Varkanitsa Maria, Carvalho Nicole, Falconer Isaac, Billot Anne, Al-Dabbagh Mohammad, Kiran Swathi
Center for Brain Recovery, Boston University, Boston, MA, United States.
Center for Brain Recovery, Boston University, Boston, MA, United States.
Cortex. 2025 Jul;188:25-41. doi: 10.1016/j.cortex.2025.04.015. Epub 2025 May 9.
Although voxel-based methods consistently identify brain regions associated with specific language functions, these techniques are limited when applied to broader behavioral measures. To better represent effects of lesions on distributed brain regions, we used a data-driven approach called non-negative matrix factorization (NMF) to identify representative stroke patterns and explore associations with aphasia severity. Lesions were segmented using structural MRIs for 107 left hemisphere stroke patients, and the Western Aphasia Battery - Revised Aphasia Quotient (AQ) was used to quantify aphasia severity. Percent spared tissue was calculated in left hemisphere white and gray matter regions. By applying NMF to spared tissue data, we identified 5 NMF 'atoms' which represent prototypical stroke patterns across this dataset. Linear regression was used to identify whether certain stroke patterns were associated with aphasia severity, adjusted for lesion volume and demographics. Two NMF atoms showed relevance in predicting AQ: strokes with low spared tissue across the whole MCA territory were associated with more severe aphasia, but strokes with high spared tissue around the insula were associated with less severe aphasia. We also identified a pattern of high spared tissue in superior fronto-parietal regions, where lesion volume was more strongly associated with severity as a result of isolating damage to more critical language areas. These representative stroke patterns offer a new way to combine information about lesion burden and location and explore anatomical associations with language dysfunction in stroke.
尽管基于体素的方法始终能够识别与特定语言功能相关的脑区,但这些技术在应用于更广泛的行为测量时存在局限性。为了更好地呈现病变对分布式脑区的影响,我们采用了一种名为非负矩阵分解(NMF)的数据驱动方法来识别代表性的中风模式,并探索其与失语严重程度的关联。我们使用107名左半球中风患者的结构磁共振成像(MRI)对病变进行分割,并使用西方失语症成套测验修订版失语商数(AQ)来量化失语严重程度。计算左半球白质和灰质区域的保留组织百分比。通过将NMF应用于保留组织数据,我们识别出5个NMF“原子”,它们代表了该数据集中的典型中风模式。我们使用线性回归来确定某些中风模式是否与失语严重程度相关,并对病变体积和人口统计学因素进行了调整。有两个NMF原子在预测AQ方面显示出相关性:整个大脑中动脉区域保留组织较少的中风与更严重的失语相关,但岛叶周围保留组织较多的中风与较轻的失语相关。我们还在额顶叶上部区域发现了一种保留组织较多的模式,由于该区域对更关键的语言区域造成孤立性损伤,病变体积与严重程度的相关性更强。这些代表性的中风模式提供了一种新方法,可将有关病变负担和位置的信息结合起来,并探索中风中与语言功能障碍的解剖学关联。