Sidtis Diana, Sidtis John J
Department of Communicative Disorders, New York University, New York 10012, USA.
Brain and Behaviour Laboratory, Geriatrics Division, Nathan Kline Institute for Psychiatric Research, Orangeburg, New York 10962, USA.
J Alzheimers Dis Parkinsonism. 2017;7(6). doi: 10.4172/2161-0460.1000392. Epub 2017 Oct 30.
Parkinson's disease (PD), caused by basal ganglia dysfunction, is associated with motor disturbances including dysarthria. Stimulation of the subthalamic nucleus, a preferred treatment targeting basal ganglia function, improves features of the motor disorder, but has uncertain effects on speech.We studied speech during contrasting stimulation states to reveal subcortical effects on voice and articulation. Measures were made on selected samples of spontaneous and repeated speech.
Persons with Parkinson's disease (PWP) who had undergone bilateral deep brain stimulation of the subthalamic nucleus (DBS-STN) provided spontaneous speech samples and then repeated portions of their monologue both on and off stimulation. Excerpts were presented in a listening protocol probing intelligibility. Also analysed were a continuous phrase repetition task and a second spontaneous speech sample. Fundamental frequency (F0), harmonic-to-noise ratio (HNR), jitter, shimmer and fluency were measured in these three speech samples performed with DBS stimulation on and off.
During subcortical stimulation, spontaneous excerpts were less intelligible than repeated excerpts. F0 and HNR were higher and shimmer was decreased in repetition and stimulation. Articulatory dysfluencies were increased for spontaneous speech and during stimulation in all three speech samples.
Deep brain stimulation disrupts fluency and improves voice in spontaneous speech, reflecting an inverse influence of subcortical systems on articulatory posturing and laryngeal mechanisms. Better voice and less dysfluency in repetition may occur because an external model reduces the speech planning burden, as seen for gait and arm reach. These orthogonal results for fluency versus phonatory competence may account for ambivalent reports from dysarthric speakers and reveal the complexity of subcortical control of motor speech.
帕金森病（PD）由基底神经节功能障碍引起，与包括构音障碍在内的运动障碍相关。刺激丘脑底核是针对基底神经节功能的一种首选治疗方法，可改善运动障碍的特征，但对言语的影响尚不确定。我们研究了在不同刺激状态下的言语，以揭示皮层下对声音和发音的影响。对自发和重复言语的选定样本进行了测量。
接受双侧丘脑底核深部脑刺激（DBS-STN）的帕金森病患者（PWP）提供自发言语样本，然后在刺激开启和关闭时重复其独白的部分内容。在一个探测可懂度的听力方案中呈现节选内容。还分析了连续短语重复任务和第二个自发言语样本。在刺激开启和关闭的情况下，对这三个言语样本测量了基频（F0）、谐波噪声比（HNR）、抖动、闪烁和流畅性。
在皮层下刺激期间，自发节选内容的可懂度低于重复节选内容。在重复和刺激时，F0和HNR较高，闪烁减少。在所有三个言语样本中，自发言语和刺激期间的发音不流畅性增加。
深部脑刺激会破坏自发言语的流畅性并改善声音，反映出皮层下系统对发音姿势和喉部机制的反向影响。重复时声音更好且不流畅性更低，可能是因为外部模型减轻了言语计划负担，就像在步态和手臂伸展中看到的那样。流畅性与发声能力的这些正交结果可能解释了构音障碍患者的矛盾报告，并揭示了皮层下对运动性言语控制的复杂性。
