Akaike Shun, Ura Shigehisa, Ogata Akihiko, Fukutake Toshio, Yabe Ichiro, Otsuki Mika
Department of Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan.
Department of Neurology, Japanese Red Cross Asahikawa Hospital, Japan.
J Neurol Sci. 2025 Sep 15;476:123602. doi: 10.1016/j.jns.2025.123602. Epub 2025 Jul 8.
Primary progressive aphasia (PPA) is a neurodegenerative syndrome with language impairment as the initial, predominant symptom. However, speech-language impairments emerge later in the disease course in a subset of neurodegenerative disorders. We introduce the term delayed progressive aphasia (DPA) to describe this subset. Within DPA, we further define delayed progressive apraxia of speech (DPAOS), characterized by isolated apraxia of speech (AOS) without aphasia.
We retrospectively reviewed patients with neurodegenerative diseases who developed speech-language impairment following an initial phase without speech or language symptoms. Six patients met the criteria for DPA and were compared with 11 patients exhibiting the nonfluent/agrammatic variant of PPA (naPPA), all of whom exhibited AOS. Disease duration since speech-language symptom onset was matched between groups. Neuropsychological performance was compared using Bayesian linear regression analysis.
All six patients who met the criteria for DPA exhibited isolated AOS without any aphasic symptoms. Accordingly, these cases were included in the DPAOS group. The Apraxia of Speech Rating Scale-3 scores were significantly lower in the DPAOS group than in the naPPA group, indicating milder AOS in the former. In the naPPA group, most patients exhibited more severe AOS, and several also showed agrammatism or anomia.
DPAOS represents a clinically distinct presentation of progressive AOS that emerges after other neurological symptoms and remains relatively mild and isolated. Despite possible overlap in underlying pathology, DPAOS and naPPA differ in clinical course and speech-language impairment severity. This distinction may aid early detection of progressive speech disorders in certain neurodegenerative conditions.
原发性进行性失语（PPA）是一种神经退行性综合征，以语言障碍为首发且主要症状。然而，在一部分神经退行性疾病的病程中，言语-语言障碍出现较晚。我们引入“迟发性进行性失语（DPA）”这一术语来描述这一亚组情况。在DPA范围内，我们进一步定义迟发性进行性言语失用（DPAOS），其特征为孤立性言语失用（AOS）且无失语。
我们回顾性研究了在初始阶段无言语或语言症状后出现言语-语言障碍的神经退行性疾病患者。6例患者符合DPA标准，并与11例表现为PPA非流利/语法缺失型（naPPA）的患者进行比较，所有naPPA患者均表现出AOS。两组之间自言语-语言症状出现后的病程时长相匹配。使用贝叶斯线性回归分析比较神经心理学表现。
所有6例符合DPA标准的患者均表现为孤立性AOS，无任何失语症状。因此，这些病例被纳入DPAOS组。DPAOS组的言语失用评定量表-3得分显著低于naPPA组，表明前者的AOS较轻。在naPPA组中，大多数患者表现出更严重的AOS，还有几例表现出语法缺失或命名障碍。
DPAOS代表了一种临床上独特的进行性AOS表现形式，它在其他神经症状出现后出现，且相对较轻且孤立。尽管潜在病理可能存在重叠，但DPAOS和naPPA在临床病程和言语-语言障碍严重程度方面存在差异。这种区别可能有助于在某些神经退行性疾病中早期发现进行性言语障碍。
