View clinical trials related to Autonomic Dysreflexia.
Filter by:In patients with spinal cord injury, the investigators want to understand and understand the differences in AD prevalence and characteristics according to bladder injection rate, and to determine which factors have a greater influence between bladder expansion or injection rate.
This project aims to evaluate the safety and efficacy of using a short-acting drug to reduce the maximal blood pressure during dangerous blood pressure spikes that happen during bowel care in individuals with spinal cord injury. the investigators will monitor the physiological effects of this drug during at-home bowel care to best understand the drug's effects in typical use.
This is a prospective, randomised study investigating the physical and psychological experience of intermittent catheterization in adult individuals following spinal cord injury (SCI).
The prevalence of autonomic dysfunction and sleep disordered breathing (SDB) is increased in individuals with spinal cord injury (SCI). The loss of autonomic control results in autonomic dysreflexia (AD) and orthostatic hypotension (OH) which explains the increase in cardiovascular related mortality in these Veterans. There is no effective prophylaxis for autonomic dysfunction. The lack of prophylactic treatment for autonomic dysfunction, and no best clinical practices for SDB in SCI, are significant health concerns for Veterans with SCI. Therefore, the investigators will investigate the effectiveness of mild intermittent hypoxia (MIH) as a prophylactic for autonomic dysfunction in patients with SCI. The investigators propose that MIH targets several mechanisms associated with autonomic control and the co-morbidities associated with SDB. Specifically, exposure to MIH will promote restoration of homeostatic BP control, which would be beneficial to participation in daily activities and independence in those with SCI.
Autonomic dysreflexia (AD) is a syndrome of unbalanced response of the sympathetic system to noxious stimuli below the level of spinal cord injury (SCI), characterized by paroxysmal hypertension. Mostly, it is combined with symptoms such as pounding headache, slowed heart rate, and upper body flushing, but it can also be asymptomatic. When resulting in hypertensive crisis, it can be life-threatening and result in seizures, cardiac arrest, retinal or subarachnoid hemorrhages, stroke, and even death. The aim of this study is to determine the risk level of vascular complications in SCI people by correlating the clinical symptoms with their individual perception during AD triggered below the level of injury.
This study looks to characterize autonomic nervous system dysfunction after spinal cord injury and identify the potential role that transcutaneous spinal cord stimulation may play at altering neuroregulation. The autonomic nervous system plays key parts in regulation of blood pressure, skin blood flow, and bladder health- all issues that individuals with spinal cord injury typically encounter complications. For both individuals with spinal cord injury and uninjured controls, experiments will utilize multiple parallel recordings to identify how the autonomic nervous system is able to inhibit and activate sympathetic signals. The investigators anticipate that those with autonomic dysfunction after spinal cord injury will exhibit abnormalities in these precise metrics. In both study populations, transcutaneous spinal cord stimulation will be added, testing previously advocated parameters to alter autonomic neuroregulation. In accomplishing this, the investigators hope to give important insights to how the autonomic nervous system works after spinal cord injury and if it's function can be improved utilizing neuromodulation.
This study looks to characterize gradients of dysfunction in the autonomic nervous system after spinal cord injury. The autonomic nervous system plays key roles in regulation of blood pressure, skin blood flow, and bladder health- all issues that individuals with spinal cord injury typically suffer. Focusing on blood pressure regulation, the most precise metric with broad clinical applicability, the investigators will perform laboratory-based tests to probe the body's ability to generate autonomic responses. For both individuals with spinal cord injury and uninjured controls, laboratory-based experiments will utilize multiple parallel recordings to identify how the autonomic nervous system is able to inhibit and activate signals. The investigators anticipate that those with autonomic dysfunction after spinal cord injury will exhibit abnormalities in these precise metrics. The investigators will further have research participants wear a smart watch that tracks skin electrical conductance, heart rate, and skin temperature, which can all provide clues as to the degree of autonomic dysfunction someone may suffer at home. The investigators will look to see if any substantial connections exist between different degrees of preserved autonomic function and secondary autonomic complications from spinal cord injury. In accomplishing this, the investigators hope to give scientists important insights to how the autonomic nervous system works after spinal cord injury and give physicians better tools to manage these secondary autonomic complications.
This study will incorporate critical cross viscero-visceral intersystem interactions to 1) investigate in a controlled laboratory setting and then with mobile at-home monitoring the extent, severity, and frequency of occurrence of autonomic dysreflexia with respect to daily bladder and bowel function, in conjunction with identifying potential underlying mechanisms by examining urinary biomarkers for several specific vasoactive hormones, and 2) to regulate cardiovascular function therapeutically as part of bladder and bowel management using spinal cord epidural stimulation.
Despite being studied less than half as frequently, autonomic dysfunction is a greater priority than walking again in spinal cord injury. One autonomic condition after spinal cord injury is orthostatic hypotension, where blood pressure dramatically declines when patients assume the upright posture. Orthostatic hypotension is associated with all-cause mortality and cardiovascular incidents as well as fatigue and cognitive dysfunction, and it almost certainly contributes to an elevated risk of heart disease and stroke in people with spinal cord injury. In addition, autonomic dysfunction leads to bladder, bowel, sexual dysfunctions, which are major contributors to reduced quality and quantity of life. Unfortunately, the available options for treating this condition, are primarily limited to pharmacological options, which are not effective and are associated with various side effects. It has been recently demonstrated that spinal cord stimulation can modulate autonomic circuits and improve autonomic function in people living with spinal cord injury. Neuroanatomically, the thoracolumbar sympathetic pathways are the primary spinal cord segments involved in blood pressure control. Recently, a pilot study has been published demonstrating that transcutaneous spinal cord stimulation of thoracolumbar afferents can improve cardiovascular function. However, some studies have shown that lumbosacral transcutaneous spinal cord stimulation can also elicit positive cardiovascular effects. Therefore, there is no consensus on the optimal strategy in order to deliver transcutaneous spinal cord stimulation to improve the function of the autonomic system, and it may be that lumbosacral (i.e. the stimulation site being used most commonly for restoring leg function is sufficient). Another key knowledge gap in terms of transcutaneous spinal cord stimulation is whether or not the current is directly or indirectly activating these spinal circuits. Last but not least, the effects of epidural spinal cord stimulation on the function of cardiovascular, bladder, bowel and sexual system in spinal cord injury have been investigated in no study yet. AIMS AND HYPOTHESES: Aim 1. To examine the effects of short-term (one session) transcutaneous spinal cord stimulation on the frequency and severity of episodes of orthostatic hypotension/autonomic dysfunction, and bladder, bowel, and sexual functions. These effects will be compared at two sites of stimulation. Hypothesis 1.1: Short-term transcutaneous mid-thoracic cord stimulation will mitigate the severity and frequency of orthostatic hypotension/autonomic dysfunction. Hypothesis 1.2: Lumbosacral transcutaneous spinal cord stimulation will improve bladder, bowel, and sexual functions. Aim 2. To examine the effects of long-term (one month) transcutaneous spinal cord stimulation on the severity and frequency of orthostatic hypotension/autonomic dysfunction. Hypothesis 2.1: Long-term stimulation of the mid-thoracic cord will result in sustained improvements in mitigated severity and frequency of orthostatic hypotension/autonomic dysfunction that is not dependent on active stimulation. Hypothesis 2.2: Long-term lumbosacral transcutaneous spinal cord stimulation will result in sustained improvements in bowel, bladder, and sexual function that is not dependent on active stimulation. Aim 3: To examine the effects of short-term (one session) epidural spinal cord stimulation on the severity and frequency of orthostatic hypotension/autonomic dysfunction, and bladder, bowel, and sexual functions. Hypothesis 3.1: Epidural spinal cord stimulation will mitigate the severity and frequency of orthostatic hypotension/autonomic dysfunction and improve bladder, bowel, and sexual function. Hypothesis 3.3: There is no significant difference between immediate effects of lumbosacral transcutaneous spinal cord stimulation and epidural spinal cord stimulation on bladder, bowel, and sexual function. For aim 1, 14 participants with spinal cord injury and no implanted electrodes on the spinal cord will be recruited. Participants will randomly receive one-hour stimulation under each of the two stimulation conditions in a crossover manner: Mid-thoracic and Lumbosacral. For aim 2, 28 individuals with spinal cord injury and no implanted electrode will be pseudo-randomized (1:1) to one of two stimulation sites. Participants will receive one-hour stimulation, five sessions per week for four weeks. Cardiovascular and neurological outcomes will be measured before the first stimulation session and after the last stimulation session. For aim 3, 4 participants with spinal cord injury with implanted electrodes on the spinal cord will be recruited to study the immediate effects of invasive epidural spinal cord stimulation. All outcomes will be measured in two positions: a) Supine, b) ~ 70° upright tilt-test. Additionally, bowel, bladder, and sexual functions in project 2 will be assessed weekly.
This is a preliminary study of the antihypertensive drug mecamylamine, used in the specific circumstance of hypertension caused by autonomic dysreflexia (AD), a condition that affects people with spinal cord injury (SCI). Initially, mild sensory stimulation of subjects' legs is used to intentionally provoke AD, as reflected by blood pressure elevation during such stimulation. In subsequent testing sessions, mecamylamine is given prior to sensory stimulation, to show the effect of the drug on preventing these AD-related blood pressure elevations.