Coordinated Microstimulation of Sacral Afferent Pathways to Control Continence and Micturition Reflexes

摘要 脊髓损伤后失去正常的膀胱控制可能会导致严重的健康后果。 事实上，脊髓损伤患者住院最常见的原因是尿路。 由于目前临床上管理膀胱功能的方法的不足而引起的并发症。此外, 围绕定期膀胱护理的社会问题会导致生活质量的下降，调查表明 脊髓损伤的人希望改善膀胱护理，而不是其他许多功能。几个 已经提出了利用神经技术改善膀胱功能的有希望的方法，然而所有的 但有几种技术未能达到临床应用。以前方法的一个基本限制是 它们还不能选择性地或同时刺激已知的分布反射通路 对正常功能有贡献。例如，刺激阴部神经中的不同感觉通路可以 引起排尿反射和排尿反射，然而，这些反射是由 骨盆神经。进入周围神经系统的所有这些通路是极具挑战性的。 该方案的目标是实现选择性地激活来自膀胱、尿路和 通过将多电极阵列植入骶骨背根神经节(DRG)来实现对生殖器的刺激。在该接口位置， 我们认为，阴部和盆腔神经的感觉神经传入可以在没有刺激的情况下选择性地受到刺激。 激活运动通路。使用这种方法，我们计划独立地调节多个反射中的活动 并将评估其对控制大小便的效果。具体地说，这些 实验建议：1)确定对骶骨背根神经节反应的传入募集模式 微刺激，2)测试单通道和多通道协同微刺激的效果 DRG传入神经对储存反射和排尿反射的募集，以及3)确定棘上反射的影响 协同多通道微刺激的通路。这些目标的成功将证明 DRG可用于实现对下尿路的分布的周围通路的访问。此访问 对膀胱神经控制的基础研究以及对 神经假体技术的发展。最终，我们的长期目标是开发一种利用 掌握脊髓控制大小便和排尿反射的知识，以恢复正常的功能控制 带着受伤的脊髓生活的人的膀胱。

Abstract The loss of normal bladder control that occurs after a spinal cord injury can lead to severe health consequences. In fact, the most common reason for hospitalization in people with spinal cord injuries is urinary tract complications that arise from deficiencies in the current clinical methods to manage bladder function. In addition, social issues surrounding regular bladder care can lead to a decrease in quality of life and surveys indicate that people with spinal cord injury desire improvements in bladder care above many other functions. Several promising approaches to improve bladder function using neurotechnologies have been proposed, however all but a few techniques have failed to reach clinical use. A fundamental limitation with previous approaches is that they have not been able to selectively or simultaneously stimulate the distributed reflex pathways known to contribute to normal function. For example, stimulation of different sensory pathways in the pudendal nerve can elicit both continence and micturition reflexes, however, these reflexes are modulated by sensory activity in the pelvic nerve. Accessing all these pathways in the peripheral nervous systems is extremely challenging. The goal of this proposal is to achieve selective activation of afferent pathways from the bladder, urethra and genitalia by implanting multielectrode arrays into the sacral dorsal root ganglia (DRG). At this interface location, we believe that sensory afferents from both the pudendal and pelvic nerves can be stimulated selectively without activating motor pathways. Using this approach, we plan to independently modulate activity in multiple reflex pathways to the spinal cord and will assess the effect on control of continence and micturition. Specifically, these experiments propose to 1) determine the patterns of afferent recruitment in response to sacral DRG microstimulation, 2) test the effects of single-channel and coordinated multichannel microstimulation of sacral DRG afferents on recruitment of storage and voiding reflexes, and 3) determine the impact of supraspinal reflex pathways on coordinated multichannel microstimulation. Success in these aims will demonstrate that the sacral DRG can be used to enable access to the distributed peripheral pathways of the lower urinary tract. This access could be useful for both fundamental investigations into the neural control of the bladder as well as for development of neuroprosthetic technologies. Ultimately, our long-term goal is to develop a device that leverages knowledge of the spinal control of continence and micturition reflexes to restore functionally normal control of the bladder to people living with injured spinal cords.