The Bases Of Normal And Disordered Laryngeal And Speech

正常和紊乱的喉部和言语的基础

• 批准号: 7324560
• 负责人: Christy Leslie Ludlow
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7324560
• 关键词: Bases; Normal; Disordered; Laryngeal; Speech

The Section conducts research on the integrated neural control of laryngeal function for voice, speech and swallowing. Our purpose is to determine the normal control system as well as the pathogenesis and pathophysiology of neurogenic disorders affecting these functions. Building on this information new treatment methods are being developed for persons with chronic pharyngeal dysphagia. Significant advances have been made during the last year in several areas. Our Section is particularly interested in the role of central gating of brain stem responses to laryngeal sensory stimulation in normalcy and in idiopathic voice disorders such as spasmodic dysphonia. In the last year we have examined how normal speakers modulate brain stem responses such as the early (R1) laryngeal adductor response during different motor control tasks such as speech in particular. We hypothesized that during phonation these brain stem responses are gated so that precise control can be maintained for phonation but that during non-phonatory tasks such as effort closure these responses would be increased because the laryngeal muscles are more active for sustained vocal fold closure. Electrical stimulation of the laryngeal afferents contained in the superior laryngeal nerve was presented during quiet inspiration, and during humming, phonation and effort closure in normal speakers. We measured the amplitude and frequency of the early R1 and later bilateral R2 responses during each of these tasks. Because the laryngeal motor neurons are firing at a more rapid rate during each of these tasks compared to inspiration, we hypothesized that the laryngeal adductor responses during these tasks would be equal to the responses at rest plus the mean increase in baseline activity during a task over the mean activity during inspiration. Not only were the laryngeal responses reduced relative to the hypothesized levels, these responses were reduced in amplitude relative to the responses occurring during respiration during all tasks. This suggests that when subjects are performing volitional laryngeal control tasks, these brain stem responses to sensory stimulation within the larynx are actively suppressed. We are now examining patients with spasmodic dysphonia to test the hypothesis that this gating of laryngeal sensory-motor responses is not normal in these patients. In mammals, the vocalization system includes the anterior cingulate, the periaquaductal grey and the integrative brain stem system to the motor neuron pools. Because electrical stimulation in the laryngeal cortex motor area only elicits vocalization in humans, it has been hypothesized that only humans have a cortically based vocalization system which is learned and involves direct corticobulbar pathways from the cortex to the brain stem. We tested this hypothesis by comparing brain activation on fMRI during vocalized syllables that only involved articulation at the larynx, such as repetition of the vowel ?ee?, with prolonged expiration without voice. We used event related neural imaging to examine specific regions of interest. An unexpected similar pattern of predominantly left hemisphere activation was found for both conditions with the only difference being auditory activation because of the greater feedback during the voiced task compared to prolonged expiration. The results indicate that a left hemisphere lateralized control system for volitional control of both prolonged exhalation and phonation are present in humans. However, in addition to activation in the left hemisphere pre-frontal and motor cortical regions, activity was also found in the supplementary motor area, the anterior cingulate and the putamen during both tasks. The findings indicate that the learned human system of voice and respiratory control for voice production is an integration of both the mammalian vocalization system and a cortically based control system. Dysphagia is a significant health problem affecting many aging adults who suffer from neurological disorders and diseases. These swallowing disorders usually stem from central nervous system injury, leaving the peripheral innervation of muscles intact but without appropriate central nervous system control. We have been studying the feasibility of using intramuscular electrical stimulation to augment airway protection by increasing hyo-laryngeal elevation during swallowing to reduce the risk of aspiration in these patients. Recently, surface electrical stimulation was introduced for use in dysphagia therapy with claims that electrical stimulation on the surface of the throat could raise the hyo-laryngeal complex. To evaluate this claim we completed two studies of the effects of surface electrical stimulation on the position of the hyoid and larynx at rest and during swallowing using videofluoroscopy. The first study involved patients with chronic pharyngeal dysphagia. When stimulation was applied at rest, the hyoid bone was lowered in the neck on average by about 10 mm. During swallowing no benefit was found in these patients airway protection with stimulation in comparison to swallowing without stimulation. In the second study 10 different stimulation combinations of surface electrode placements were used in healthy volunteers and in all those placements over the laryngeal area the hyoid was lowered in the neck to the same degree on videofluoroscopy. In addition, submental surface stimulation did not elevate either the larynx or the hyoid bone. Finally, in the healthy subjects when stimulation was applied over the larynx significant reductions occurred in peak elevation of both the larynx and hyoid bone during stimulated swallows. The stimulated swallows were also judged less safe than non-stimulated swallows on a scale measuring penetration of liquid during swallowing in these healthy individuals. In conclusion, surface electrical stimulation not only did not benefit patients but may place patients at increased risk of aspiration because of increased resistance to hyoid elevation during swallowing. We have continued our studies of intramuscular stimulation to aid swallowing in patients with chronic pharyngeal dysphagia and a Phase II controlled trial comparing an implanted neuromuscular stimulator with sensory stimulation for the treatment of patients with chronic pharyngeal dysphagia is planned to start next year.

该部分对语音，语音和吞咽的喉功能的综合神经控制进行了研究。我们的目的是确定正常的控制系统以及影响这些功能的神经源性疾病的发病机理和病理生理学。在此信息的基础上，正在针对患有慢性咽吞咽困难的人开发新的治疗方法。去年在多个领域取得了重大进展。 我们的部分对正常和特发性语音疾病（如痉挛性吞咽困难）中脑干反应的中心析出对脑干的反应的作用特别感兴趣。在去年，我们研究了正常的扬声器如何调节脑干反应，例如在不同的运动控制任务中，尤其是语音等不同的运动控制任务中的早期（R1）喉内收肌反应。我们假设在发声过程中，这些大脑茎反应是门控的，因此可以保持精确的控制以进行发音，但是在非发音任务（例如努力闭合）期间，这些反应会增加，因为喉部肌肉更为活跃，以持续发声闭合。在安静的灵感期间，在上喉神经中包含的喉部神经中包含的喉部传入以及在正常扬声器中嗡嗡作响，发声和努力闭合时。在每个任务中，我们测量了R1早期和后来的双侧R2响应的幅度和频率。由于与Inspion相比，在每个任务期间，喉运动神经元在每个任务中都以更快的速度发射，因此我们假设这些任务期间的喉内收肌反应等于静止的响应，以及在灵感过程中平均活动中任务期间的基线活动的平均值增加。不仅相对于假设的水平，喉反应不仅减少了，而且相对于所有任务期间呼吸过程中发生的反应，这些响应的幅度降低了。这表明当受试者执行自愿性喉部控制任务时，这些脑干对喉内感觉刺激的反应会被积极抑制。我们现在正在检查痉挛性吞咽困难的患者，以检验以下假设：这些患者在这些患者中的这种喉感觉运动反应不正常。 在哺乳动物中，发声系统包括前扣带回，肢部灰色和脑干的综合脑干系统。由于喉皮质运动区域中的电刺激仅引起人类的发声，因此假设只有人类具有基于皮质的发声系统，该系统被学到并涉及直接的皮质骨途径，从皮质从皮质到脑干。我们通过在发声音节期间对fMRI的大脑激活进行比较，该假设仅涉及喉头上的发音，例如重复元音？我们使用与事件相关的神经成像来检查感兴趣的特定区域。对于这两种情况，发现了一种主要的左半球激活模式，唯一的差异是听觉激活，因为在声音任务期间与长期到期相比的反馈更大。结果表明，人类中存在一个左半球侧向控制系统，以进行长时间的呼气和发音。但是，除了在左半球前额外和运动皮质区域的激活外，还发现了在补充运动区域，在两个任务过程中的前扣带回和壳虫。研究结果表明，语音生产的人类语音和呼吸控制系统是哺乳动物发声系统和基于皮层的控制系统的整合。 吞咽困难是影响许多患有神经系统疾病和疾病的成年人的重大健康问题。这些吞咽疾病通常源自中枢神经系统损伤，使肌肉的周围神经支配完好无损，但没有适当的中枢神经系统控制。我们一直在研究使用肌内电刺激在吞咽过程中增加Hyo脑淋巴结升高以降低这些患者吸入风险，从而增加气道保护的可行性。最近，引入了表面电刺激以用于吞咽困难治疗，并声称喉咙表面的电刺激可能会增加Hyo Laryngeal络合物。为了评估这一说法，我们完成了两项研究，介绍了表面电刺激对使用视频荧光学吞咽和吞咽期间舌体和喉部位置的影响。第一项研究涉及慢性咽吞咽困难的患者。当静止时施加刺激时，舌骨平均在颈部降低约10毫米。在吞咽过程中，与吞咽没有刺激相比，这些患者的气道保护没有发现任何益处。在第二项研究中，在健康的志愿者中使用了10种不同的表面电极位置组合，并且在喉部区域的所有这些位置中，在视频荧光镜检查中降低了颈部的舌体。此外，下表面刺激不会升高喉或舌骨。最后，在健康受试者中，在喉头上施加刺激时，在刺激燕子期间喉头和舌骨的峰值升高时发生了显着降低。在这些健康个体中，吞咽过程中测量液体渗透的尺度上，刺激的燕​​子也比未刺激的燕子更不安全。总之，由于对吞咽过程中对舌体升高的耐药性的增加，表面电刺激不仅没有使患者受益。我们继续对肌内刺激的研究有助于吞咽慢性咽吞咽困难和II期对照试验，该试验比较了植入的神经肌肉刺激剂与感觉刺激的治疗，以治疗慢性咽鼻涕的患者，计划明年开始。