14 Clinical Trials for Various Conditions
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.
The purpose of this research study is to determine if DBS is a feasible, safe and effective therapy for pain and autonomic dysreflexia after spinal cord injury.
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.
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.
This study will determine if posture and heart rate variability will significantly improve in Parkinsons disease with camptocormia after osteopathic manual treatments dystonia.
While treatment strategies for OH have been identified for use in persons with acute SCI, the field of SCI medicine lacks a gold standard for treatment thresholds and well-defined outcome parameters. Comprehensively documenting the impact of orthostatic hypotension (OH), regardless of symptoms, during acute rehabilitation and identifying the effects of two different treatment approaches on therapy participation and adherence to an intended rehabilitation plan could have a significant impact on clinical practice in the acute rehabilitation setting following SCI.
Dysregulation of blood pressure (BP), secondary to decentralized autonomic nervous system (ANS) control of the cardiovascular system, often results in chronic hypotension and orthostatic hypotension (OH) in persons with spinal cord injury (SCI), particularly in those with high cord lesions (i.e., above T6). While most hypotensive individuals with chronic SCI remain asymptomatic and do not complain of symptoms associated with cerebral hypoperfusion, evidence of reduced resting cerebral blood flow (CBF) has been reported in association with low systemic BP in the SCI and non-SCI populations. Reduced CBF in hypotensive individuals may lead to cognitive dysfunction, and we reported significantly impaired memory and marginally impaired attention processing in hypotensive individuals with SCI compared to a normotensive SCI cohort. Furthermore, we found that CBF was not increased during cognitive testing in individuals with SCI, which may contribute to impaired cognitive function compared to non-SCI controls. Although asymptomatic hypotension may have an adverse impact on cognitive function and quality of quality of life (QOL) clinical management of this condition is extremely low. In fact, we reported that while nearly 40% of Veterans with SCI were hypotensive, less than 1% carried the diagnosis of hypotension or were prescribed an anti-hypotensive medication. The discrepancy between incidence and treatment of asymptomatic hypotension in the SCI population may relate to a paucity of treatment options which are supported by rigorous clinical trials documenting safe and effective use of anti-hypotensive therapy on BP, CBF and cognitive function. We hypothesize these study medications may increase systolic blood pressure to the normal range and improve cerebral blood flow velocity. Results and conclusions will not be removed from the record.
The investigators would like to improve our understanding of how early intervention with the use of bladder chemodenervation can preserve bladder function in those with a new SCI. Although detrimental cystometric and tissue changes are known to occur, often within 3 months after SCI, the investigators seek to document the time course of these changes and the range of severity of those changes in both those participants that receive prophylactic treatment and those who do not.
The general population is aging, today 12% of the United States population is older than 65 and it is estimated that by 2020 the number of people in the United States older than 65 will outnumber children younger than 5. As the general population ages, the spinal cord injury (SCI) population is also aging and it is estimated that 14% is older than 60. Although persons with SCI are living longer, life expectancy remains below that of the general population with cardiovascular and cerebrovascular diseases accounting for more than 25% of all deaths since 1995. Similar to findings in the general population, BP dysregulation may impact cognitive function, and investigators reported poorer performance on tasks of memory and attention processing in hypotensive individuals with SCI compared to a normotensive SCI cohort. Thus, it is imperative that investigators work to minimize the impact of cognitive deficits on these aspects of life quality in persons with SCI as they age. Therefore the goals of this study are: Study 1) to compare cardiovascular, cerebrovascular and cognitive function and fMRI between older individuals with SCI (50-75 years) and older age-matched controls and Study 2) to determine 3-5 year longitudinal changes in cardiovascular, cerebrovascular and cognitive function and fMRI in relatively young individuals with SCI (28-54 years) compared to relatively young age-matched controls.
Increased life expectancy in individuals with spinal cord injury (SCI) present clinicians with the challenge of managing the secondary complications of SCI with the chronic diseases common in an aging population. Cardiovascular disease, cerebral vascular disease, and cognitive dysfunction are among the primary challenges facing clinicians in the treatment of an aging population. Cognitive dysfunction has been reported in upwards of 60% of the SCI population, which have been primarily attributed to concomitant traumatic brain injury or pre-morbid conditions. Identifying possible modifiable risk factors which contribute to the increased prevalence of cognitive dysfunction in the SCI population is of significant clinical relevance and cardiovascular and cerebrovascular disorders have emerged as possible contributors to the cognitive disorders in the general population. These risk factors include: physical inactivity, chronically low or high blood pressure (BP), reduced blood flow to the brain, arterial stiffening, and impaired nervous system regulation of the cardiovascular system. These risk factors are particularly prominent in the SCI population as they represent a model of profound inactivity, have trouble regulating blood pressure, and suffer impaired cardiovascular regulation from their injury. In addition, we've recently reported deficits in blood flow to the brain at rest and during cognitive tests; with results being further impaired in SCI with chronically low blood pressure. Therefore the goals of this project are to determine the influence of cardiovascular and cerebral vascular responses at rest and during cognitive testing on test performance in 80 individuals with SCI compared to 50 age-matched non-SCI controls. All potential subjects will undergo a rigorous two-part screening process which consists of an initial screening via telephone and a detailed, in-person screening. Eligible subjects will be invited to participate in a 3 hour laboratory visit during which their arterial stiffness, blood pressure, heart rate, respiration rate and, blood flow to the brain will be monitored at rest and during a comprehensive series of cognitive tests. We hypothesize that blood pressure and cerebrovascular response to testing will account significantly for performance in cognitive testing that otherwise would have been attributable to SCI status.
As the spinal cord injured population ages, these individuals are being exposed to an increased prevalence of age-associated diseases, which coupled with the secondary complications of the injury may contribute to the reduced life expectancies. Decentralized autonomic regulation in persons with SCI results in a multitude of cardiovascular changes, which may contribute to accelerated aging. Adverse cardiovascular changes may have deleterious effects on cerebral blood flow dynamics and an increase in cerebral vascular resistance index in individuals with SCI during cognitive testing. Deficits in memory and processing speed in individuals with SCI may relate to cardiovascular and cerebrovascular dysfunction. Identifying the associations between healthy aging versus premature or accelerated aging in organ system function in the SCI population is an important first step towards prevention and amelioration of these changes. Therefore the study objectives are to compare, among individuals with SCI, age-matched non-SCI and older non-SCI individuals arterial stiffness and cerebral vascular resistance index; memory, processing speed, and executive function; and volume of white matter hyperintensities. 60 individuals with SCI, 30 age-matched non-SCI controls, and 20 older non-SCI controls will be recruited for this study. All potential subjects will undergo a two-part screening process which consists of an initial screening via telephone and a detailed, in-person screening. Eligible subjects will be invited to participate in a 4 hour laboratory visit during which their arterial stiffness, blood pressure, heart rate, respiration rate and, blood flow to the brain will be monitored at rest and during a comprehensive series of cognitive tests. A subset of the participants will be asked to take part in an MRI brain imaging session: 40 persons with SCI, 10 age-matched non-SCI and 10 older non-SCI. Eligible subjects will be asked to participate in a 1 hour MRI/functional magnetic resonance imaging(fMRI) session. We hypothesize that arterial stiffness and cerebral vascular resistance index will be increased in the SCI group compared to the age-matched non-SCI but will be comparable to the older non-SCI groups. In addition, we hypothesize that the prevalence of mild to moderate cognitive impairments in memory, processing speed, and executive function will be increased in the SCI individuals compared to the age-matched non-SCI but will be comparable to the older non-SCI individuals.
People with a spinal cord injury (SCI) have limited ability to move and feel sensation below the level of the SCI. Doctors and researchers have tests which determine the level of function and sensation, this test was developed by the American Spinal Cord Injury Association (ASIA) and has been modified over the years to improve use and sensitivity. Most recently, the ASIA Injury classification Scale (AIS) was modified in 2011, but this test does not include the evaluation of autonomic nervous system (ANS) impairment. However, people with SCI do have impairment of the ANS and this may adversely affect how organ systems in the body function. Specifically, ANS impairment tends to result in changes in heart rate and blood pressure that may relate to the level of the SCI, but this is not fully understood. In this investigation we hope to develop simple tests which will allow doctors and scientist the ability to measure the amount of ANS impairment to the cardiovascular system, specifically the heart. The first part of the study will be to determine the heart rate response to several tests (administration of drugs and physical challenges) which will change heart rate. These tests will be given to people with and without SCI and the heart rate response will be compared between people with and without SCI. The bigger the difference in the heart rate response to these test between people with and without SCI the greater degree of ANS impairment in the people with SCI. Once this heart rate difference is determined, several simple tests (deep breathing, saliva test, Valsalva) will be performed in people with and without SCI to again compare the heart rate response. The second part of this study will be to determine if the heart rate responses to the first set of tests (administration of drugs and physical challenges) can predict the heart rate response to these simple tests (deep breathing, saliva test, Valsalva). The aim of this study is to develop a simple battery of tests which can be easily used by doctors and scientists to determine the degree of ANS impairment to the heart in persons with SCI.