29 Clinical Trials for Various Conditions
Cognitive impairment after moderate to severe traumatic brain injury (msTBI) not only significantly affects the quality of life in individuals with msTBI, but also increases the possibility of late-life dementia. The goal of this study is to determine whether acute (\< 1 week) cerebrovascular injury and its recovery within the first year postinjury measured by cerebral autoregulation and brain perfusion are associated with cognitive outcome at 12 months after msTBI. The results from this study will improve our understanding of cerebrovascular contributions to cognitive decline related to TBI and provide critical data to inform the development of strategies based on vascular mechanisms to improve cognition and prevent neurodegeneration after msTBI.
The goal of this observational study is to learn the how to determine the mean arterial pressure(MAP) or blood pressure level to be maintained during non-cardiac surgery for optimal brain health in patients above the age of 60 undergoing major non-cardiac surgery. The main question\[s\] it aims to answer are: * Is there a way to tailor the blood pressure to be maintained in such patients during surgery for optimal brain health using non-invasive monitors that check the brains electrical activity, the electroencephalogram(EEG) monitor, and the brain's blood oxygen levels, the cerebral oximetry(CO) monitor? * How much does this optimal blood pressure level vary between patients? Participants will be asked to: * Complete a questionnaire at the time they enroll into the study, as well as a daily questionnaire to help determine their level of thinking and brain health. This questionnaire will be administered by a member of the study team. * They will also have an EEG and CO monitoring sticker placed on their foreheads. This will be connected to a monitor that will collect this data just before, during, and after their surgery. The data collected through these monitors will help us with our study goals.
The purpose of this study is to conduct a pilot trial to determine the feasibility, safety, and potential efficacy of targeting mean arterial blood pressure (MAP) within the limits of cerebral autoregulation during surgery compared with usual care.
The purpose of this research study is to develop a protocol for NIRS-based bedside monitoring to identify impaired cerebral autoregulation in women admitted to the high-risk obstetrics unit with postpartum hypertension. The investigators will then pilot this protocol in 10 patients with high-risk neurological features, such as headache.
Various methods have been studied to evaluate autoregulation. However, there is currently no universally accepted technique to assess integrity of the cerebral autoregulation neurovascular system. In the last decade, significant progress has been achieved in developing methods to assess cerebral autoregulation by quantifying cross-correlation between spontaneous oscillations in CBF or oxygenation and similar oscillations in arterial blood pressure. In this study the investigators will analyze the relationship between spontaneous fluctuations in mean arterial blood pressure and cerebral blood flow velocity or cerebral regional oxygenation to investigate two novel methods for measuring cerebral autoregulation, Transfer Function Analysis and Wavelet Coherence after acute pediatric brain injury.
This study will collect retrospective and prospective clinical data regarding the Principal Investigator's patient population to allow for data analysis seeking basic trends and to prepare academic reports, including journal manuscripts and presentations for scientific organizations.
Traumatic brain injury (TBI) affects 1.5 million patients per year in the United States, resulting in more than 50,000 deaths and more than 230,000 hospitalizations annually. Approximately 90,000 of these patients will suffer permanent impairment and more than half will experience short-term disability. Secondary injury processes play a critical role in the development of ischemia after trauma to the central nervous system and occur hours-to-days after the primary insult. Ischemia can lead to cerebral infarction or stroke. Ischemia has been described as the single most important secondary insult and has been identified histologically in approximately 90% of patients who die following closed head injury. Several factors resulting in post-traumatic cerebral ischemia have been identified: increased intracranial pressure (ICP), systemic arterial hypotension, and cerebral vasospasm. Cerebral vasospasm has been described as a sustained arterial narrowing. Clinically, the onset of new or worsening neurological symptoms is the most reliable indicator of cerebral vasospasm following a ruptured cerebral aneurysm. However, cerebral vasospasm is often unrecognized in patients suffering from moderate to severe TBI. These patients frequently have altered mental status due to the primary brain injury. In addition, they require narcotics for their pain and paralytics and/or sedatives while on a mechanical ventilator for airway protection. Thus, relying on the neurological exam to observe deteriorating neurological signs consistent with post-traumatic vasospasm (PTV) is reliable. While the etiology and outcome of patients with vasospasm secondary to ruptured aneurysm is well documented, the clinical significance of PTV after TBI is unknown. A better understanding of the role of cerebral autoregulation in the development of cerebral vasospasm could provide the answer. This proposal is for a pilot observational study describing the association of the impairment of cerebral autoregulation as measured by near infrared spectroscopy (NIRS) with the development of clinically significant vasospasm in patients with moderate to severe TBI. The information will serve as preliminary data for further study.
Cerebral autoregulation (CA) is a complex mechanism that serves the essential and vital purpose of controlling cerebral blood flow and metabolism. A stable and optimal brain blood flow is imperative for normal brain function. Diabetes Mellitus (DM ) is associated with microvascular disease that alters CA and also with autonomic failure that may lead to orthostatic hypotension (OH). These conditions may lead to decreased brain blood flow in upright position. This observational study will compare two technologies that evaluate brain blood flow during standing up and other maneuvers in people with and without type 2 diabetes. These technologies are transcranial Doppler and UTLight technology (CerOx). This study will determine the safety and feasibility of CerOx technology for continuous monitoring of cerebral blood flow.
This study investigates if there are hemodynamic alterations in acute stroke that predispose patients to impaired perfusion and regulation of cerebral blood flow. To test this, we will target recruitment of acute ischemic stroke patients who present to the ED within 12 hours of symptoms onset. Enrolled subjects will receive continuous noninvasive hemodynamic monitoring contemporaneous with measurements of cerebral blood flow velocities and cerebral oximetry.
Delirium (confusion) after surgery is common and associated with a longer hospitl stay and increased hopsital cost. There is very little information available about how often delirium occurs and the complications associated with it. Elderly patients are at high risk for delirium after surgery. This research is being done to measure how often delirium after spine surgery occurs and to see if there are ways to predict if delirium will develop. The results from this study will provide important information on a possible mechanism and predictor of delirium.
Neurological complications from cardiac surgery are an important source of operative mortality, prolonged hospitalization, health care expenditure, and impaired quality of life. New strategies of care are needed to avoid rising complications for the growing number of aged patients undergoing cardiac surgery. This study will evaluate novel methods for reducing brain injury during surgery from inadequate brain blood flow using techniques that could be widely employed.
The purpose of this study is to determine the feasibility of using the NeuraSignal transcranial doppler robot in a neuro ICU setting to measure cerebral blood flow correlated with arterial blood pressure to generate individualized cerebral autoregulatory curves
The purpose of this research, which has been determined as non-significant risk by the central IRB overseeing the study, is to obtain information to help further develop a machine (a medical device) to measure the pressure around the brain from the outside (this pressure is called intracranial pressure or ICP). Monitoring and managing ICP is an important part of care for patients with conditions such as Traumatic Brain Injury (TBI). However, the current way of measuring ICP requires surgery to drill a hole into the skull, and therefore can introduce additional risks such as infections and pain. Recent research has shown it may be possible to measure ICP without needing surgery. This technology is in development, but large amounts of data is required to build these new devices. Through collecting a large database of information from patients who have both the routine surgical device and the research device applied to their head, the research team will work to develop and test an effective and potentially safer way of monitoring patient ICP.
The objective of this project is to study the cerebrovascular response to a single bout of high intensity interval exercise (HIIT) in 25 individuals with chronic stroke compared to 25 age- and sex- matched healthy controls (CON). We will enroll 25 young healthy adults (CONyoung) as a reference group. Our hypothesis is that the cerebrovascular response in individuals with chronic stroke will be significantly lower: 1) during a single bout of HIIT, and 2) during the recovery immediately following and 30 minutes after HIIT, compared to CON. This study has 2 visits at the University of Kansas Medical Center Research in Exercise and Cardiovascular Health Laboratory. For the first visit, we will perform questionnaires about heart health, physical activity and overall health. Participants will then complete a submaximal exercise test on a seated stepper. Participants will also have a familiarization session to practice HIIT. The second visit will include cerebrovascular measures before, during, immediately after, and 30 minutes after performing HIIT.
Extremely low birth weight (ELBW), birth weight less than or equal to 1000 g, infants are at high risk for developing brain injury in the first week of life. Intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL) are the most common injuries in this group of infants. Their incidence is inversely proportional to gestational age (GA) and birth weight (BW). These lesions are associated with neurodevelopmental delay, poor cognitive performance, visual and hearing impairment, epilepsy, and cerebral palsy; and instability of systemic hemodynamics during transition from intra- to extra-uterine life and during the early neonatal period is believed to be at their genesis. While the incidence of ultrasound- diagnosed cystic PVL has decreased dramatically over the last 2 decades, diffuse PVL detected by magnetic resonance imaging (MRI) is still prevalent in survivors of neonatal intensive care. Moreover, PVL, even when non-cystic, is associated with decreased cortical complexity and brain volume and eventual neurocognitive impairment. Currently, clinicians lack the tools to detect changes in cerebral perfusion prior to irreversible injury. Unfortunately, the incidence of brain injury in ELBW infants has remained relatively stable. Once translated to the bedside, the goal of this research is to develop a monitoring system that will allow researchers to identify infants most at risk for IVH and PVL and in the future, intervention studies will be initiated to use the changes in cerebral perfusion to direct hemodynamic management. The purpose of this study is to first understand the physiology of brain injury and then to eventually impact the outcomes in this high-risk group of infants by assessing the ability of the diastolic closing margin (DCM), a non-invasive estimate of brain perfusion pressure, to predict hemorrhagic and ischemic brain injury in ELBW infants. The information collected for this study will help develop algorithms or monitoring plans that will maintain the appropriate brain perfusion pressure and thereby, prevent severe brain injury.
The investigators will test the central hypothesis that DFO treatment after SAH may improve cerebrovascular regulation, mitigate ischemic neural injury, and serve as an effective neuroprotectant against delayed ischemic injury after SAH.
One of the fundamental goals of anesthesia care is to optimize tissue perfusion and oxygenation, especially in critically ill patients. The standard monitors such as blood pressure, heart rate and pulse oximetry do not directly reflect tissue information and can be misleading sometimes. Coherent hemodynamics spectroscopy (CHS) based on cerebral oximetry is proposed as a continuous and non-invasive tool assessing cerebral microvascular hemodynamics. The investigators propose this study to explore the validity of CHS via comparison with transcranial Doppler measurement in anesthetized surgical patients. The hypotheses are: 1) CHS can effectively measure cerebral microvascular hemodynamic changes associated with mechanical ventilation adjustment during anesthesia. 2) CHS can assess functional status of cerebral autoregulation that is altered by hypercapnia and inhalational anesthetic agent.
Premature infants are at high risk for variations in blood pressure and oxygenation during the first few days of life. The immaturity of the premature brain may further predispose these infants to death or the development of neurologic problems. The relationship between unstable blood pressure and oxygen levels and brain injury has not been well elucidated. This study investigates the utility of near-infrared spectroscopy (NIRS), a non-invasive oxygen-measuring device, to identify preterm infants at highest risk for brain injury or death.
Annually, almost 5,000 extremely low birth weight (9 ounces to about 2 lbs) infants born in the US survive with severe bleeding in the brain (intraventricular hemorrhage); this devastating complication of prematurity is associated with many problems, including mental retardation, cerebral palsy, and learning disabilities, that result in profound individual and familial consequences. In addition, lifetime care costs for these severely affected infants born in a single year exceed $3 billion. The huge individual and societal costs underscore the need for developing care strategies that may limit severe bleeding in the brain of these tiny infants. The overall goal of our research is to evaluate disturbances of brain blood flow in these tiny infants in order to predict which of them are at highest risk and to develop better intensive care techniques that will limit severe brain injury. 1. Since most of these infants require ventilators (respirators) to survive, we will investigate how 2 different methods of ventilation affect brain injury. We believe that a new method of ventilation, allowing normal carbon dioxide levels, will normalize brain blood flow and lead to less bleeding in the brain. 2. We will also examine how treatment for low blood pressure in these infants may be associated with brain injury. We believe that most very premature infants with low blood pressure actually do worse if they are treated. We think that by allowing the infants to normalize blood pressure on their own will allow them to stabilize blood flow to the brain leading to less intraventricular hemorrhage. 3. In 10 premature infants with severe brain bleeding, we have developed a simple technique to identify intraventricular hemorrhage before it happens. Apparently, the heart rate of infants who eventually develop severe intraventricular hemorrhage is less variable than infants who do not develop this. We plan to test this method in a large group of infants, to be able to predict which infants are at highest risk of developing intraventricular hemorrhage and who could most benefit from interventions that would reduce disturbances of brain blood flow.
Advances in newborn intensive care have lead to dramatic improvements in survival for the most premature infants-often weighing 1 pound at birth. Unfortunately, cerebral palsy, mental retardation, and developmental delay affect more than 10,000 of these premature infants in the U.S. annually. In his studies, Dr. Jeffrey R. Kaiser is trying to understand why these premature infants are at such high risk of brain injury, and to learn ways to prevent injury. Experts believe that disturbances of brain blood flow regulation are important in causing these injuries. Using a novel continuous monitoring system, Dr. Kaiser is able to determine an infant's capacity for normal brain blood flow regulation. Contrary to previous thinking, he has shown that many of these babies in fact due have normal regulation of their brain blood flow. He has observed that brain blood flow may be disturbed during suctioning of the breathing tube. Further, he has also shown that infants with high carbon dioxide, those not breathing well, have impaired regulation of their brain blood flow. Thus, even stable infants are prone to disturbed brain regulation during routine intensive care, which may lead to bleeding in the brain and long-term neurologic problems. Dr. Kaiser will study up to 200 infants to determine 1) the developmental pattern of normal regulation of cerebral blood flow; 2) in those with impaired regulation, determine when it develops during the first week of life; and 3) determine the relationship between impaired brain blood flow regulation and brain injury. Results from this study will help us recognize when premature infants are most vulnerable to developing brain injury, allowing prevention and intervention strategies to be initiated in a timely fashion.
The overall objective of this study is to evaluate the use of diffuse correlation spectroscopy to non-invasively measure dynamic cerebral autoregulation in subjects with vascular risk factors. Optical cerebral blood flow measurements will be correlated with changes in arterial blood pressure to assess how CBF is maintained in response to changes in ABP, and will be compared to transcranial doppler reference measurements.
The goal of this trial is to assess the performance of the OxiplexTS-an absolute near-infrared oximeter-as an instrument to measure brain oxygenation and hemodynamics in sleep medicine as well as in the broader field of cardiovascular/cerebrovascular diagnostics.
Rheoencephalography (REG) shows promise as a method for noninvasive neuromonitoring, because it reflects cerebrovascular reactivity. This protocol will study clinical and technical conditions required to use REG. Additionally, our goal is to study noninvasive peripheral bioimpedance pulse waveforms in order to substitute invasive SAP. A previous study demonstrated that REG can be used to detect spreading depolarization (SD), the early sign of brain metabolic disturbance. SD can be measured invasively with DC EEG amplifiers only. Our goal is to create an automatic notification function for REG monitoring indicating change of clinical conditions.
BACKGROUND: The brain is very sensitive to both excessive and insufficient flow of blood. Cerebral blood flow (CBF) is normally auto-regulated by the blood vessels in the brain, but this protective mechanism is often disturbed after a traumatic brain injury (TBI). Impairment or loss of the CBF autoregulation makes the brain vulnerable to oscillations of either arterial blood pressure (ABP) or intracranial pressure (ICP). The ideal management of TBI patients, therefore, involves continuous measurement and management of the cerebral perfusion pressure (CPP = ABP - ICP) but the measurement of CPP is currently possible only with specialized equipment and expertise that is not available in all institutions. The investigators have converted a no-longer used system that continuously monitors CBF autoregulation using rheoencephalography (REG) technology into a modern, small, battery-powered, low-cost monitor (aka BM-1) that acquires the REG signals using only noninvasive electrodes placed on the skin/scalp. REG data can then be used to calculate the optimal CPP to maintain in each individual patient. BM-1 is also capable of monitoring electroencephalography (EEG) and impedance plethysmography (IPG), which can, respectively, be used to measure brain electrical activity and changes in peripheral blood flow caused by blood pressure changes. OBJECTIVES: The primary objectives are to (Obj. 1) demonstrate that REG acquired noninvasively is equal to the well-established but invasive method using intracranial pressure (ICP) monitoring, (Obj. 2) retrospectively test the idea that TBI patients have a less favorable outcome if their CPP were found less optimal using the REG data, and (Obj. 3) determine if noninvasive IPG or the PPG finger sensor monitoring (used to measure heart rate in doctor's offices) can replace the invasive monitoring of arterial blood pressure (ABP). METHODOLOGY: This is an observational study with retrospective data analysis. 20 adult patients (18-65 yrs) with acute TBI, who meet the inclusion/exclusion criteria, will be enrolled on a first-come-first-enroll basis. The enrolled patients will have the REG, EEG and IPG signals monitored for the duration of ICU stay or 15 days, whichever is shorter. Standard neurological assessment will be made at the patient's discharge from the ICU and at 3 months after injury. The study is expected to end June 2013.
Neurological injury after elective shoulder surgery in the beach chair position is thought to result from cerebral hypoperfusion and should therefore be preventable by appropriate hemodynamic monitoring and management. This proposal will use a system to continuously monitor cerebral blood flow autoregulation to identify safe arterial blood pressure targets in patients in the beach chair position, compared with a control cohort having orthopedic surgery in the lateral decubitus supine position. Autoregulation data will be compared against a new, highly specific and sensitive serum biomarker of neurologic injury, glial fibrillary acid protein, and postoperative neurocognitive testing results.
Blood flow to the brain is normally regulated to ensure a constant supply of blood with oxygen and nutrients. During heart surgery using cardiopulmonary bypass, blood pressure is kept at a level that may or may not be below an individual's lower level of brain blood flow autoregulation. If lower, the brain may be exposed to an inadequate blood flow that could result in brain damage. The purpose of this study is to examine whether monitoring with a non-invasive FDA approved device that measures oxygen saturation of the superficial layers of the brain (near infrared spectroscopy) can, when combined with blood pressure measurements, provide information on the blood pressure level where brain blood flow is not autoregulated. The goal of this research is to develop a method to individualize blood pressure during surgery to a level that is within a patient's brain blood flow autoregulation range as a means for improving outcomes for patient undergoing heart surgery.
One of the challenges in pediatric anesthesiology is to ensure adequate cerebral perfusion pressure to prevent cerebral ischemia or hyperemia from pressure-passive perfusion. However, there is no optimal tool for longitudinally monitoring cerebral perfusion under general anesthesia (GA). In addition, the safe limits of blood pressure that maintains adequate cerebral perfusion in infants and children are not clear. Furthermore, patients with neurological impairments may have impaired cerebral auto-regulation (CA) function which may associated with functional outcomes. To address the critical public health issues associated with the safe use of general anesthesia in during neurosurgery, monitoring cerebral perfusion and oxygenation continuously during the peri-operative period. The investigators have pioneered a novel technology, diffuse correlation spectroscopy (DCS), to optically measure cerebral blood flow (CBF) non-invasively and demonstrated that it is safe and practical as a bedside CBF monitor in the NICU. Blood flow is distinct from blood oxygenation, but both are important for brain health. Clinical near infrared spectroscopy (NIRS) devices are available to monitor oxygenation by light absorption, but CBF must be monitored by light scattering, which is only available with research DCS devices. While the physical principles of the methods are different, the sensors for both techniques are very similar. The investigators have therefore combined DCS with advanced frequency-domain NIRS (FDNIRS) in a single device to simultaneously monitor cerebral tissue oxygen saturation (cStO2), blood volume (CBV), CBF and oxygen metabolism (CMRO2), which cannot be monitored with existing clinical devices. The investigators have previously shown that these measures are far more sensitive than cStO2 alone in several infant brain pathologies. In this study, the investigators aim to test the feasibility of integrating the FDNIRS-DCS technology into perioperative monitoring to study cerebral hemodynamics and oxygen metabolism continuously in children during general anesthesia and surgery. Additionally, the investigators will determine how anesthesia-related events affect cerebral hemodynamic instability and how anesthetic level correlates with CA functions in children.
Cardiac surgery is associated with multiple events and issues that increase risk for adverse postoperative neurological outcomes including postoperative cognitive dysfunction. The risk for postoperative delirium is generally thought to result from some previous health factors added to the susceptibility of the cardiac surgery process.
The primary objective of this project is to investigate the effect of statin therapy on cerebral blood flow in patients with aneurysmal SAH who are randomized to receive or not receive statins in a blinded design.