Evaluation of Wire Electrodes to Activate the Expiratory Muscles to Restore Cough

描述(由申请人提供)：本申请涉及广泛的挑战领域(06)使能技术和具体的挑战主题，06-NS-104：开发和验证辅助神经技术。在脊髓损伤患者中，由于不能咳嗽和不能清除分泌物，呼吸道并发症是导致严重发病率和死亡率的原因。这些人缺乏有效的咳嗽机制，因为他们的伤害往往会导致几乎所有的呼气肌瘫痪。因此，这些患者依赖于护理员的帮助来应用手动吸痰、辅助咳嗽或其他呼吸道管理方法。这些方法繁琐，通常不舒服，需要训练有素的人员，而且经常限制患者的行动。由于大多数患者损伤平面以下的脊髓是完整的，脊髓的运动神经元和周围神经肌肉机构仍有功能。因此，呼气肌应该适应功能性电刺激技术，以恢复有效的咳嗽机制。在一项针对四肢瘫痪受试者的单部位先导性研究中，我们最近表明，脊髓刺激可以电激活呼气肌，这是一种通过椎板切开手术放置盘状电极的方法。电极位于下胸椎和上腰椎水平的背侧硬膜外间隙。这项研究的结果表明，这种方法成功地实现了呼气肌激活的有效方法，如大气道压力和最大气流速度的产生。重要的是，这项技术促进了分泌物的清除，减少了对照顾者支持的需求，减少了呼吸道感染的发生率，并提高了生活质量。因此，这项技术有可能降低医疗保健成本，提高脊髓损伤受试者的存活率。尽管取得了成功，但由于电极放置所需的侵入性操作，许多脊髓损伤患者不愿使用这项技术。然而，我们的假设是，呼气肌可以通过线电极实现类似的激活，这种电极可以通过针经皮插入，消除了侵入性椎板切开术的需要，并可以在门诊进行。后一种方法将提高患者和医生对这项技术的接受度，缩短恢复时间，并显著降低成本。因此，这项工作的目的是直接比较导线电极和以前使用的圆盘电极的效果。在6名接受盘状电极永久性植入止咳的患者中，我们计划直接比较临时放置几种不同的盘状电极系统与盘状电极所获得的呼气肌激活程度。通过监测手术室中不同电极系统电刺激时呼吸道压力和最大气流产生速率的变化，来比较呼气肌的激活程度。该试验的结果将提供a)有关电线电极的大小和刺激配置以实现最佳呼气肌肉激活的至关重要的数据，b)利用微创技术恢复咳嗽的额外人体研究的框架，以及c)可能修改我们的研究设备豁免(IDE)以在使用电线电极方面通过脊髓刺激恢复咳嗽的必要数据。 公共卫生相关性：由于无法咳嗽，肺炎等呼吸道并发症是脊髓损伤受试者致残和死亡的主要原因。这项拟议的研究的目的是评估一种利用可经皮插入的脊髓导线电极来电激活呼气肌以恢复咳嗽的微创方法。这项技术可能会得到患者和医生的广泛接受，显著减少对护理人员支持的需求，促进呼吸道分泌物的管理，减少呼吸道感染的发生率，降低成本，并提高这类患者的生活质量。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (06) Enabling Technologies and Specific Challenge Topic, 06-NS-104: Developing and validating assistive neuro-technologies. Respiratory complications account for significant morbidity and mortality in patients with spinal cord injury due to their inability to cough and clear secretions. These individuals lack an effective cough mechanism due to the fact that their injury often results in paralysis of virtually all of their expiratory muscles. Consequently these patients are dependent upon caregiver assistance for the application of manual suctioning, assisted coughing maneuvers or other methods of airway management. These methods are cumbersome, generally uncomfortable, require trained personnel and often restrict patient mobility. Since the spinal cord below the level of injury is intact in most patients, the motoneurons of the spinal cord and peripheral neuromuscular apparatus remain functional. Therefore, the expiratory muscles should be amenable to functional electrical stimulation techniques to restore an effective cough mechanism. In a single site, pilot study in tetraplegic subjects, we have recently shown that the expiratory muscles can be electrically activated by spinal cord stimulation, a method which involves the surgical placement of disc electrodes through laminotomy incisions. Electrodes are positioned in the dorsal epidural space at the lower thoracic and upper lumbar spinal levels. The results of this study indicate that this method is successful in achieving an effective means of expiratory muscle activation, as demonstrated by the generation of large airway pressures and peak airflow rates. Importantly, this technique facilitates secretion removal, reduces the need for caregiver support, reduces the incidence of respiratory tract infections and improves life quality. This technique therefore has the potential to reduce health care costs and improve survival in spinal cord injured subjects. While successful, many individuals with spinal cord injury are reluctant to pursue this technique due to the invasive procedure required for electrode placement. It is our hypothesis however that comparable activation of the expiratory muscles can be achieved with wire electrodes which can be inserted percutaneously through a needle, eliminating the need for the invasive laminotomy procedure and can be performed on an out-patient basis. This latter procedure would increase patient and physician acceptance of this technique, shorten recovery times and significantly reduce costs. The purpose of this undertaking therefore is to directly compare the efficacy of wire electrodes vs the previously employed disc electrodes. In 6 patients undergoing permanent implantation of disc electrodes to restore cough, we plan to directly compare the degree of expiratory muscle activation achieved with temporary placement of several different wire electrode systems with the disc electrodes. The degree of expiratory muscle activation will be compared by monitoring the changes in airway pressure and peak airflow rate generation achieved during electrical stimulation with different electrode systems in the Operating Room. The results of this trial will provide a) critically important data concerning the size and stimulus configuration of wire electrodes resulting in optimal expiratory muscle activation, b) the framework for additional human studies utilizing minimally invasive techniques to restore cough and c) necessary data for a possible amendment of our Investigational Device Exemption (IDE) to restore cough via spinal cord stimulation, with regard to use of wire electrodes. PUBLIC HEALTH RELEVANCE: Due to their inability to cough, respiratory complications such as pneumonia are a major cause of disability and death in subjects with spinal cord injury. The purpose of the proposed study is to evaluate a minimally invasive method of electrical activation of the expiratory muscles to restore cough utilizing spinal cord wire electrodes which can be inserted percutaneously. This technique would likely have wide patient and physician acceptance, significantly reduce the need for caregiver support, facilitate management of respiratory secretions, reduce the incidence of respiratory tract infections, reduce costs and improve life quality in this patient population.