ABSTRACT

Background: Verb and sentence processing impairments are frequently observed in people with aphasia (PWA). However, patterns of impairment (i.e. combinations of deficits that are revealed by arrays of tasks) are usually investigated at the group level, by selecting groups of patients with specific aphasia types (e.g., non-fluent variants with signs of agrammatism), or in case-series with relatively small samples.

Aims: We aimed to explore patterns of impairment in verb and sentence processing in a large (N = 54) group of PWA with various aphasia types, using methods that do not require a priori aphasia-type information.

Methods & Procedures: To assess verb and sentence processing impairments in production and comprehension, we used the Verb and Sentence Test (VAST) adapted to Russian (VAST-Ru). As our main method, we used k-means cluster analysis to group individuals based on their scores on different tasks of the VAST-Ru. We then compared cluster allocations to aphasia types (according to Alexander Luria’s classification) established by a standard clinical evaluation procedure. As a follow up, we investigated performance of each person with aphasia on each task by comparing their individual scores to the control group.

Outcomes & Results: The k-means analysis grouped the PWA into two clusters. The main difference between the clusters was the severity of impairment across most of the tasks, both at the single verb and at the sentence level, both in production and in comprehension. All participants with efferent motor aphasia (roughly corresponding to Broca’s aphasia) and most of the participants with acoustic-mnestic aphasia (roughly corresponding to anomic aphasia) were in the less-impaired cluster. Complex aphasia types (complex motor and complex temporal aphasia) pertained to the more-impaired cluster, while other aphasia types (dynamic aphasia, corresponding to transcortical motor, and sensory, corresponding to Wernicke’s aphasia) were more or less evenly distributed over two clusters. Individual-level analysis revealed heterogeneous patterns of impairment in both clusters and across different aphasia types.

Conclusions: These results demonstrate that verb and sentence impairments are prevalent in aphasia, irrespective of the aphasia type. They also indicate that aphasia severity mediates verb and sentence impairment in aphasia. We could not find a clear correspondence between individual patterns of impairment and aphasia type at this stage. The clinical implications are discussed.

摘要

背景：在失语症 (PWA) 患者中经常观察到动词和句子处理障碍。然而，损害模式（即由一系列任务揭示的缺陷组合）通常在组级别进行调查，通过选择具有特定失语类型（例如，具有语法错误迹象的非流利变体）的患者组，或在样本相对较少的案例系列。

目的：我们旨在使用不需要先验失语症类型信息的方法，在具有各种失语症类型的大型 ( N = 54) PWA 组中探索动词和句子处理受损的模式。

方法和程序：为了评估生产和理解中的动词和句子处理障碍，我们使用了适用于俄语的动词和句子测试 (VAST) (VAST-Ru)。作为我们的主要方法，我们使用k- means 聚类分析根据他们在 VAST-Ru 的不同任务上的分数对个人进行分组。然后，我们将聚类分配与通过标准临床评估程序建立的失语症类型（根据 Alexander Luria 的分类）进行比较。作为后续行动，我们通过将每个失语症患者的个人得分与对照组进行比较，调查了每个失语症患者在每项任务中的表现。

结果＆结果：该ķ-means 分析将 PWA 分为两个集群。集群之间的主要区别在于大多数任务的损伤严重程度，无论是在单个动词还是在句子级别，无论是在生产还是在理解方面。所有患有传出运动性失语症（大致对应于布罗卡失语症）的参与者和大多数患有听觉记忆性失语症（大致对应于失语症）的参与者都属于受损程度较低的集群。复杂失语症类型（复杂运动和复杂时间性失语）属于更受损的集群，而其他失语类型（动态失语，对应于跨皮质运动和感觉，对应于韦尼克失语症）或多或少均匀分布在两个集群上。

结论：这些结果表明动词和句子障碍在失语症中普遍存在，而与失语症类型无关。他们还表明失语症的严重程度介导了失语症的动词和句子损伤。在此阶段，我们无法找到个体损伤模式和失语类型之间的明确对应关系。讨论了临床意义。