Effects of aging on swallowing physiology with transient cortical disruption

描述(由申请人提供)：老年人受吞咽障碍或吞咽困难的影响不成比例，这是一种可能导致发病率和死亡率增加的情况。吞咽开始延迟是神经源性吞咽困难的一种常见和破坏性的病理生理学，健康的老年人也会经历这种情况，使功能性吞咽不太安全。此前，我们已经表明，健康的老年人显著推迟了吞咽的开始，并增加了初级感觉-运动皮质(SMI)的神经激活，这一现象在年轻人中是不存在的。然而，目前尚不清楚SMI激活的差异是否导致吞咽起始的延迟或其后果随着年龄的增加而延迟。这项建议的目标是：(1)了解SMI在吞咽启动中的功能作用；(2)表征衰老对吞咽启动的影响；以及(3)使Humbert博士获得神经科学、感觉-运动控制和老化吞咽生理学方面的专门培训。总体假设是，SMI的短暂中断将在年轻人和老年人吞咽开始时产生可测量的延迟，但老年人将有更明显的缺陷。我们将在吞咽过程中的不同时间间隔对双侧SMI喉代表进行单脉冲经颅磁刺激(TMS)，同时进行视频透视和肌电(EMG)检查，以检测健康年轻人和老年人吞咽发作的变化。这项调查将确定皮层区域是否参与了吞咽的启动，以及这一功能的时机选择的重要性。我们还将能够通过测试年轻人和老年人来确定老年人是否有能力降低对SMI的干扰。这项拟议调查的结果意义重大，因为老年人口更容易因阿尔茨海默病、中风和帕金森病等神经损害而出现吞咽困难。从这项研究中获得的知识将成为制定科学合理的战略以减少这一共同的医疗保健问题的基础，这一问题给我们的社会带来了负担。相关性(见说明)：这项调查与公共健康有关，因为它将确定老年人是否有能力降低对大脑的干扰，导致吞咽延迟。这一点意义重大，因为老年人口更有可能因阿尔茨海默病、中风和帕金森病而出现吞咽障碍。从这项研究中获得的知识将有助于制定干预措施，以减少这个给我们的社会带来负担的常见医疗保健问题。

DESCRIPTION (provided by applicant): Older adults are disproportionately affected by swallowing impairment, or dysphagia, a condition that can lead to increased morbidity and death. Delayed initiation of swallowing is a common and devastating pathophysiology of neurogenic dysphagia, and is also experienced by healthy older adults, making functional swallowing less safe. Previously we have shown that healthy older adults have significantly delayed swallowing onset as well as increased neural activation in the primary sensory-motor cortex (SMI), a phenomenon absent in younger adults. However, it is still not known if differences in activation of SMI are responsible for delays in swallowing initiation or its consequence with advancing age. The goals of this proposal are; (1) to understand the functional role of SMI on swallowing initiation; (2) to characterize the effect of aging on swallowing initiation with transient cortical disruption; and, (3) for Dr. Humbert to obtain specialized training in neuroscience, sensory-motor control, and aging swallowing physiology. The overall hypothesis is that transient disruption of SMI will produce measurable delays in swallowing initiation in young and old adults, but older adults will have more pronounced deficits. We will apply single-pulse transcranial magnetic stimulation (TMS) to the bilateral SMI laryngeal representation with concurrent video fluoroscopy and electromyography (EMG) during swallowing at various temporal intervals to examine changes in swallowing onset in healthy young and old adults. This investigation will determine whether cortical areas are involved in initiating swallowing as well as the importance of timing on this function. We will also be able to determine whether older adults have a decreased ability to counteract the disruptions to SMI by testing young and old adults. The results from this proposed investigation is significant because the geriatric population is more prone to developing dysphagia due to neurological impairment such as Alzheimer's disease, stroke, and Parkinson's disease. The knowledge gained in this study will become the foundation to develop scientifically sound strategies to reduce this common health care problem that burdens our society. RELEVANCE (See instructions): This investigation is relevant to public health because it will determine whether older adults have a decreased ability to counteract disruptions to the brain, causing delays in swallowing. This is significant because the geriatric population is more likely to develop swallowing impairment due to Alzheimer's disease, stroke, and Parkinson's disease. The knowledge gained in this study will help to develop interventions to reduce this common health care problem that burdens our society.