Fan Joline M, Gorno-Tempini Maria Luisa, Dronkers Nina F, Miller Bruce L, Berger Mitchel S, Chang Edward F
Department of Neurology, University of California, San Francisco, San Francisco, CA, United States.
Department of Psychology, University of California, Berkeley, Berkeley, CA, United States.
Front Neurol. 2020 Dec 29;11:616764. doi: 10.3389/fneur.2020.616764. eCollection 2020.
Aphasia classifications and specialized language batteries differ across the fields of neurodegenerative disorders and lesional brain injuries, resulting in difficult comparisons of language deficits across etiologies. In this study, we present a simplified framework, in which a widely-used aphasia battery captures clinical clusters across disease etiologies and provides a quantitative and visual method to characterize and track patients over time. The framework is used to evaluate populations representing three disease etiologies: stroke, primary progressive aphasia (PPA), and post-operative aphasia. A total of 330 patients across three populations with cerebral injury leading to aphasia were investigated, including 76 patients with stroke, 107 patients meeting criteria for PPA, and 147 patients following left hemispheric resective surgery. Western Aphasia Battery (WAB) measures (Information Content, Fluency, answering Yes/No questions, Auditory Word Recognition, Sequential Commands, and Repetition) were collected across the three populations and analyzed to develop a multi-dimensional aphasia model using dimensionality reduction techniques. Two orthogonal dimensions were found to explain 87% of the variance across aphasia phenotypes and three disease etiologies. The first dimension reflects shared weighting across aphasia subscores and correlated with aphasia severity. The second dimension incorporates fluency and comprehension, thereby separating Wernicke's from Broca's aphasia, and the non-fluent/agrammatic from semantic PPA variants. Clusters representing clinical classifications, including late PPA presentations, were preserved within the two-dimensional space. Early PPA presentations were not classifiable, as specialized batteries are needed for phenotyping. Longitudinal data was further used to visualize the trajectory of aphasias during recovery or disease progression, including the rapid recovery of post-operative aphasic patients. This method has implications for the conceptualization of aphasia as a spectrum disorder across different disease etiology and may serve as a framework to track the trajectories of aphasia progression and recovery.
失语症的分类以及专门的语言测试组合在神经退行性疾病和脑损伤领域存在差异，这使得跨病因比较语言缺陷变得困难。在本研究中，我们提出了一个简化框架，其中一个广泛使用的失语症测试组合能够捕捉不同疾病病因的临床集群，并提供一种定量和可视化的方法来随时间表征和跟踪患者。该框架用于评估代表三种疾病病因的人群：中风、原发性进行性失语（PPA）和术后失语。对总共330名因脑损伤导致失语的三个群体的患者进行了调查，其中包括76名中风患者、107名符合PPA标准的患者以及147名接受左半球切除手术的患者。收集了三个群体的西方失语症成套测验（WAB）测量数据（信息内容、流畅性、回答是/否问题、听觉单词识别、顺序指令和复述），并进行分析，以使用降维技术建立一个多维失语症模型。发现两个正交维度可以解释失语症表型和三种疾病病因中87%的方差。第一个维度反映了失语症子分数的共同权重，并且与失语症严重程度相关。第二个维度纳入了流畅性和理解能力，从而将韦尼克失语与布罗卡失语区分开来，以及将非流畅性/语法缺失型与语义性PPA变体区分开来。代表临床分类的集群，包括晚期PPA表现，在二维空间中得以保留。早期PPA表现无法分类，因为需要专门的测试组合来进行表型分析。纵向数据进一步用于可视化失语症在恢复或疾病进展过程中的轨迹，包括术后失语患者的快速恢复。这种方法对于将失语症概念化为跨不同疾病病因的谱系障碍具有启示意义，并且可以作为一个框架来跟踪失语症进展和恢复的轨迹。
