Tetzloff Katerina A, Duffy Joseph R, Clark Heather M, Josephs Keith A, Whitwell Jennifer L, Utianski Rene L
Department of Neurology, Mayo Clinic, Rochester, MN.
Department of Radiology, Mayo Clinic, Rochester, MN.
J Speech Lang Hear Res. 2024 Mar 11;67(3):811-820. doi: 10.1044/2023_JSLHR-23-00577. Epub 2024 Feb 20.
Apraxia of speech (AOS) is a motor speech disorder affecting articulatory planning and speech programming. When AOS is the sole manifestation of neurodegeneration, it is termed primary progressive apraxia of speech (PPAOS). Recent work has shown that there are distinct PPAOS subtypes: phonetic, prosodic, and those that do not clearly align with either (mixed). PPAOS subtypes differ with respect to the predominating motor speech difficulties, as well as disease progression and underlying pathology. Because past studies have determined PPAOS subtype based on clinical impression, the goal of the present study was to quantitatively determine the distribution of speech error types across PPAOS subtypes in a word repetition task and to investigate how word complexity affects the type and number of speech errors across PPAOS subtypes.
Forty-five patients with PPAOS (13 phonetic, 23 prosodic, and nine mixed) and 45 healthy controls produced multiple repetitions of words that varied in phonetic complexity. Sound additions, deletions, and substitutions/distortions (phonetic errors) and within-word segmentations (prosodic errors) were calculated.
All three PPAOS groups produced significantly more errors than controls, but the total number of errors was comparable among subtypes. The phonetic group produced more phonetic-type errors compared to the prosodic group but comparable to the mixed group. The prosodic group produced more segmentations compared to the phonetic and mixed PPAOS groups. As word complexity increased, the total number of errors increased for PPAOS patients. The phonetic and prosodic groups were more likely to produce phonetic- and prosodic-type errors, respectively, as word complexity increased.
This study provides novel quantitative data showing that PPAOS subtype can be supported by the type and distribution of speech errors in a word repetition task. This may facilitate earlier, more reliable differential diagnosis and aid in disease prognosis, as PPAOS subtypes have distinct disease trajectories.
言语失用症（AOS）是一种影响发音计划和言语编程的运动性言语障碍。当AOS是神经退行性变的唯一表现时，它被称为原发性进行性言语失用症（PPAOS）。最近的研究表明，PPAOS有不同的亚型：语音型、韵律型以及那些与两者都不太相符的（混合型）。PPAOS亚型在主要的运动性言语困难、疾病进展和潜在病理方面存在差异。由于过去的研究是基于临床印象来确定PPAOS亚型的，本研究的目的是定量确定在单词重复任务中PPAOS各亚型言语错误类型的分布，并研究单词复杂性如何影响PPAOS各亚型言语错误的类型和数量。
45名PPAOS患者（13名语音型、23名韵律型和9名混合型）和45名健康对照者对语音复杂性不同的单词进行多次重复。计算增加音、删除音以及替换/歪曲（语音错误）和词内分割（韵律错误）的情况。
所有三个PPAOS组产生的错误都明显多于对照组，但各亚型之间的错误总数相当。语音型组产生的语音型错误比韵律型组多，但与混合型组相当。韵律型组产生的分割错误比语音型和混合型PPAOS组多。随着单词复杂性的增加，PPAOS患者的错误总数增加。随着单词复杂性的增加，语音型和韵律型组分别更有可能产生语音型和韵律型错误。
本研究提供了新的定量数据，表明在单词重复任务中，言语错误的类型和分布可以支持PPAOS亚型的划分。这可能有助于更早、更可靠的鉴别诊断，并有助于疾病预后，因为PPAOS亚型有不同的疾病轨迹。
