Division of Speech and Hearing Sciences, The University of North Carolina at Chapel Hill.
Am J Speech Lang Pathol. 2023 Aug 17;32(4S):1825-1834. doi: 10.1044/2022_AJSLP-22-00170. Epub 2023 Jan 5.
Behaviorally, acquired apraxia of speech (AOS) is a multidimensional syndrome that the experienced clinician recognizes based on impaired articulation and abnormal temporal prosody. We conducted this study to determine the extent to which three core features of AOS-when defined quantitatively-distinguish categorically among aphasia with no or minimal speech sound involvement, aphasia with AOS, and aphasia with phonemic paraphasia (APP).
The study involved retrospective analysis of 195 participants with stroke-induced aphasia. We used three quantitative measures (phonemic error frequency, distortion error frequency, and word syllable duration [WSD]) to divide the sample into four participant groups according to the most likely speech diagnosis: aphasia with minimal speech sound errors, AOS, APP, and a borderline group with mixed profiles. We then conducted nonparametric comparisons across groups for which the measures were not defined and visualized all three measures in a three-dimensional graph.
The measures distributed as multidimensional spectra rather than discrete diagnostic entities, and there was considerable behavioral overlap among participant groups. Thirty percent of participants presented with aphasia with minimal sound production difficulties, and they were statistically indistinguishable from the APP group on distortion frequency and WSD. Distortion frequency and WSD were in a borderline region between AOS and APP for 29% of participants. Compared to all other groups, participants with AOS produced significantly more errors that affected listeners' phonemic perception.
The results suggest that the current AOS-APP dichotomy has limited validity. We conclude that a continuous multidimensional view of speech variation would be a constructive perspective from which to understand how the left cerebral hemisphere produces speech and that quantitative and normed speech measures should be used to inform differential diagnosis in clinical settings.
从行为学角度来看，获得性言语失用症（AOS）是一种多维综合征，有经验的临床医生可以根据发音障碍和异常时程韵律来识别。我们进行这项研究是为了确定 AOS 的三个核心特征（定量定义）在多大程度上可以将无或最小语音参与的失语症、有 AOS 的失语症和有音位错语症（APP）的失语症进行分类。
本研究回顾性分析了 195 名因中风导致的失语症患者。我们使用了三个定量指标（音位错误频率、失真错误频率和单词音节时长[WSD]），根据最可能的言语诊断将样本分为四组：语音错误最小的失语症、AOS、APP 和混合特征的边界组。然后，我们对没有定义这些指标的组进行了非参数比较，并在三维图中可视化了所有三个指标。
这些指标呈多维谱分布，而不是离散的诊断实体，并且参与者组之间存在相当大的行为重叠。30%的参与者表现出最小的语音生产困难的失语症，他们在失真频率和 WSD 上与 APP 组在统计学上无法区分。失真频率和 WSD 在 AOS 和 APP 之间的边界区域为 29%的参与者。与所有其他组相比，AOS 患者产生的明显更多的错误影响了听众的音位感知。
结果表明，目前的 AOS-APP 二分法的有效性有限。我们的结论是，从理解左大脑半球如何产生语音的角度来看，连续的多维言语变异观点将是一个有建设性的观点，定量和规范的言语测量应该用于在临床环境中进行鉴别诊断。
