Department of Neurology, Mayo Clinic, Rochester, MN.
Department of Health Sciences Research, Mayo Clinic, Rochester, MN.
J Speech Lang Hear Res. 2023 Aug 17;66(8S):3194-3205. doi: 10.1044/2022_JSLHR-22-00286. Epub 2023 Feb 13.
The purpose of this study was to describe, compare, and understand speech modulation capabilities of patients with varying motor speech disorders (MSDs) in a paradigm in which patients made highly cued attempts to speak faster or slower.
Twenty-nine patients, 12 with apraxia of speech (AOS; four phonetic and eight prosodic subtype), eight with dysarthria (six hypokinetic and two spastic subtype), and nine patients without any neurogenic MSD completed a standard motor speech evaluation where they were asked to repeat words and sentences, which served as their "natural" speaking rate. They were then asked to repeat lower complexity (counting 1-5; repeating "cat" and "catnip" 3 times each) and higher complexity stimuli (repeating "catastrophe" and "stethoscope" 3 times each and "My physician wrote out a prescription" once) as fast/slow as possible. Word durations and interword intervals were measured. Linear mixed-effects models were used to assess differences related to MSD subtype and stimuli complexity on bidirectional rate modulation capacity as indexed by word duration and interword interval. Articulatory accuracy was also judged and compared.
Patients with prosodic AOS demonstrated a reduced ability to go faster; while they performed similarly to patients with spastic dysarthria when counting, patients with spastic dysarthria were able to increase rate similar to controls during sentence repetition; patients with prosodic AOS could not and made increased articulatory errors attempting to increase rate. AOS patients made more articulatory errors relative to other groups, regardless of condition; however, their percentage of errors reduced with an intentionally slowed speaking rate.
The findings suggest comparative rate modulation abilities in conjunction with their impact on articulatory accuracy may support differential diagnosis between healthy and abnormal speech and among subtypes of MSDs (i.e., type of dysarthria or AOS). Findings need to be validated in a larger, more representative cohort encompassing several types of MSDs.
本研究旨在描述、比较和理解不同运动性言语障碍（MSD）患者在一种高度提示性尝试更快或更慢说话的范式中的言语调节能力。
29 名患者，12 名言语失用症（AOS；4 名语音和 8 名韵律亚型），8 名构音障碍（6 名运动迟缓型和 2 名痉挛型亚型），9 名无任何神经源性 MSD 的患者完成了一项标准的言语运动评估，要求他们重复单词和句子，作为他们的“自然”说话速度。然后要求他们尽可能快地重复较低复杂度（计数 1-5；重复“cat”和“catnip”各 3 次）和较高复杂度的刺激（重复“catastrophe”和“stethoscope”各 3 次和“My physician wrote out a prescription”一次）。测量单词时长和词间间隔。使用线性混合效应模型评估与 MSD 亚型和刺激复杂度相关的差异，以单词时长和词间间隔为指标，评估双向语速调节能力。还评估并比较了发音准确性。
韵律性 AOS 患者的语速加快能力降低；在计数时，他们与痉挛性构音障碍患者表现相似，但在句子重复时，痉挛性构音障碍患者能够像对照组一样提高语速；而韵律性 AOS 患者则不能，并且在试图提高语速时会犯更多的发音错误。与其他组相比，AOS 患者无论在何种情况下都会犯更多的发音错误；然而，随着说话速度的有意减慢，他们的错误率会降低。
这些发现表明，比较的语速调节能力及其对发音准确性的影响可能有助于健康和异常言语之间以及 MSD 亚型（即构音障碍或 AOS 类型）之间的鉴别诊断。需要在更大、更具代表性的包含多种 MSD 类型的队列中验证这些发现。
