Sidtis John J, Sidtis Diana Van Lancker, Ramdhani Ritesh, Tagliati Michele
Brain and Behavior Laboratory, Geriatrics Division, the Nathan Kline Institute, 140 Old Orangeberg Road, Building 35, Orangeburg, NY 10962, USA.
Department of Psychiatry, New York University-Langone School of Medicine, 550 First Avenue, New York, NY 10016, USA.
Brain Sci. 2020 Jan 2;10(1):26. doi: 10.3390/brainsci10010026.
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has become an effective and widely used tool in the treatment of Parkinson's disease (PD). STN-DBS has varied effects on speech. Clinical speech ratings suggest worsening following STN-DBS, but quantitative intelligibility, perceptual, and acoustic studies have produced mixed and inconsistent results. Improvements in phonation and declines in articulation have frequently been reported during different speech tasks under different stimulation conditions. Questions remain about preferred STN-DBS stimulation settings. Seven right-handed, native speakers of English with PD treated with bilateral STN-DBS were studied off medication at three stimulation conditions: stimulators off, 60 Hz (low frequency stimulation-LFS), and the typical clinical setting of 185 Hz (High frequency-HFS). Spontaneous speech was recorded in each condition and excerpts were prepared for transcription (intelligibility) and difficulty judgements. Separate excerpts were prepared for listeners to rate abnormalities in voice, articulation, fluency, and rate. Intelligibility for spontaneous speech was reduced at both HFS and LFS when compared to STN-DBS off. On the average, speech produced at HFS was more intelligible than that produced at LFS, but HFS made the intelligibility task (transcription) subjectively more difficult. Both voice quality and articulation were judged to be more abnormal with DBS on. STN-DBS reduced the intelligibility of spontaneous speech at both LFS and HFS but lowering the frequency did not improve intelligibility. Voice quality ratings with STN-DBS were correlated with the ratings made without stimulation. This was not true for articulation ratings. STN-DBS exacerbated existing voice problems and may have introduced new articulatory abnormalities. The results from individual DBS subjects showed both improved and reduced intelligibility varied as a function of DBS, with perceived changes in voice appearing to be more reflective of intelligibility than perceived changes in articulation.
丘脑底核（STN）的深部脑刺激（DBS）已成为治疗帕金森病（PD）的一种有效且广泛应用的工具。STN-DBS对言语有多种影响。临床言语评分表明STN-DBS后言语情况恶化，但定量可懂度、感知和声学研究结果却参差不齐且相互矛盾。在不同刺激条件下的不同言语任务中，常报告有发声改善和清晰度下降的情况。关于最佳的STN-DBS刺激设置仍存在疑问。对7名接受双侧STN-DBS治疗的右利手、以英语为母语的PD患者在三种刺激条件下进行了非药物状态研究：刺激器关闭、60赫兹（低频刺激-LFS）以及185赫兹的典型临床设置（高频-HFS）。在每种条件下记录自发言语，并准备摘录用于转录（可懂度）和难度判断。还准备了单独的摘录供听众对声音、清晰度、流畅性和语速方面的异常进行评分。与关闭STN-DBS相比，高频和低频刺激时自发言语的可懂度均降低。平均而言，高频刺激时产生的言语比低频刺激时更易理解，但高频刺激使可懂度任务（转录）在主观上更困难。刺激开启时，声音质量和清晰度均被判定为更异常。STN-DBS在低频和高频刺激时均降低了自发言语的可懂度，但降低频率并未提高可懂度。STN-DBS时的声音质量评分与无刺激时的评分相关。清晰度评分则不然。STN-DBS加剧了现有的声音问题，并且可能引发了新的清晰度异常。来自个体DBS受试者的结果显示，可懂度的提高和降低随DBS而变化，声音方面的感知变化似乎比清晰度方面的感知变化更能反映可懂度。
