65 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.
This study is being done to examine whether transcranial direct current stimulation (tDCS) will increase cerebral blood flow which may provide a clinical benefit such as improving cognitive impairment.
Study using ultrasound of the brain as a diagnostic tool to differentiate between ischemic stroke and hemorrhagic stroke. Correlation of brain perfusion and size of stroke in relation to systemic hemodynamic targets will be assessed on serial scans.
The purpose of this study is to determine if intensive lowering of systolic blood pressure (SBP), using FDA approved medications (antihypertensive), reduces Alzheimer's Disease pathology (i.e., excessive brain amyloid and tau protein deposition) in older adults at high risk for memory decline or dementia.
The study aims to investigate the relationship between neuropsychological functioning and brain perfusion in patients undergoing carotid endarterectomy and control patients undergoing other peripheral vascular procedures.
Across broad surgical populations, cerebral hypoperfusion is associated with increased mortality, stroke, brain cellular injury, and poor functional outcomes. Based on available evidence, The Brain Trauma Foundation recommends that cerebral perfusion pressure (CPP) be maintained greater than 60 mmHg in high-risk settings to minimize risk of cerebral ischemia. Though several lines of investigation have focused on optimal cerebrovascular management in the intensive care unit and cardiac surgery settings, much less focus has been placed on cerebrovascular management during non-cardiac surgery. Preliminary data indicate that intraoperative CPP routinely falls below 60 mmHg in neurosurgical and trauma surgery settings, though the relationship between reduced intraoperative CPP and outcomes remains unclear. Furthermore, effective methods by which low intraoperative CPP could be prevented have not been thoroughly investigated, which represents the first required step prior to studying the relationship between intraoperative CPP and clinical outcomes. Thus, the aim of this study is to evaluate the efficacy of an automated algorithm that alerts clinicians to a decrease in CPP below 60 mmHg. This study tests the hypothesis that an automated pager alert system (triggered by CPP falling below 60 mmHg) will increase intraoperative CPP compared to standard of care.
This is a double blind placebo controlled trial in Parkinson's disease (PD) patients with neurogenic orthostatic hypotension (NOH). Investigators hypothesize that the study drug (droxidopa) may improve cerebral perfusion more robustly than systemic BP, possibly by direct action within the CNS vasculature. This study is designed to determine if droxidopa improves cerebral perfusion measures in PD patients with NOH, in addition to peripheral BP measures and subjective responses.
The overall objective of this study is to test for perturbations in intraoperative electroencephalogram (EEG) , cerebral blood flow (CBF), cerebral metabolic rate of oxygen consumption (CMRO2), oxygen extraction fraction (OEF), and serum and cerebral spinal fluid biomarkers associated with delirium in high risk population having elective hip arthroplasty at Penn Presbyterian Medical Center (PPMC).
The purpose of the study is to evaluate the physiological response to application of the Intrathoracic Pressure Regulator (ITPR) in patients with compromised cerebral circulation. The study will evaluate the physiological response to intrathoracic pressure regulation (IPR) therapy in hemodynamically stable patients with compromised cerebral circulation who are on ventilatory support.
The goal of this study is to demonstrate Or-Nim's CerOx monitor ability to monitor changes in cerebral blood flow and oximetry during CEA surgery. Procedures include: Screening: ECG, blood draw, neurological assessment, NIHSS study: CerOX and TCD clock during CEA procedure, data collection from the medical record/monitors, neurological assessment, NIHSS 30 day follow-up
The purpose of this study is to learn whether blood flow in the brain is normal in people with pantothenate kinase-associated neurodegeneration (PKAN). Specifically, preliminary data suggest a region of the brain called the globus pallidus (GP), a key region affected by PKAN, may have reduced blood flow. Standard MRI and perfusion scanning techniques will be used to learn about cerebral blood flow in the globus pallidus and compare it to blood flow in other brain regions as well as to healthy controls.
The purpose of the study is to evaluate the physiological response to application of the Intrathoracic Pressure Regulator (ITPR) in patients with compromised cerebral circulation. The study will evaluate the physiological response to intrathoracic pressure regulation (IPR) therapy in hemodynamically stable patients with compromised cerebral circulation who are on ventilatory support.
The long-term goal is to determine if decreased blood flow to the brain (cerebral hypoperfusion) is predictive of antidepressant outcomes in late-life depression (LLD). Studies in younger adult report that successful antidepressant treatment is associated with increases in cerebral blood flow, with no change in blood flow being observed in nonresponders. Thus cerebral hypoperfusion may be a biomarker of poor response to antidepressants. In LLD, this may occur secondarily to underlying vascular disease. If LLD is characterized by cerebral hypoperfusion and it does have predictive power to identify individuals who will poorly respond to conventional antidepressants, this would support the study of interventions that improve cerebral perfusion and may improve antidepressant outcomes. As an initial step in this research, this pilot study will utilize MRI to examine if resting blood flow deficits predict and persist with antidepressant nonremission in an elderly population. The rationale for this proposal is that it will guide the design and power requirements of a larger, definitive trial examining the relationship between cerebral perfusion and depression outcomes. Importantly, support for this mechanism being linked to LLD would also support studies examining the antidepressant efficacy of drugs that may improve cerebral perfusion. The primary purpose of this pilot study is a) to demonstrate feasibility by recruiting, scanning, and treating depressed elders; and b) to acquire preliminary data for competitive grant submissions. SPECIFIC AIM: To use MRI to test for differences in cerebral perfusion between individuals who do and do not remit to a 8-week course of sertraline.
Ventricular tachycardia (VT) is a life-threatening, fast heart rhythm that starts in the lower chambers of the heart (the ventricles). This fast heartbeat is caused by abnormal electrical pathways located in the heart tissue. A standard procedure called a catheter ablation has been used for several years to help correct these abnormal pathways and, in some cases, improve or even eliminate the ventricular tachycardia. During a VT ablation it is routine to monitor your vital signs (blood pressure, heart rate, and oxygen saturation in your blood). If you choose to participate in this study we will also monitor your cerebral oximetry, the amount of blood flow and oxygen saturation to your brain during the ablation. By doing this study, we hope to have a better understanding of patients' blood and oxygen flow to their brain during an episode of Ventricular Tachycardia (VT).
The focus of this study is to gather preliminary data regarding the effects of a psychological therapy-Problem Solving Therapy-and an antidepressant medication-sertraline-on 1) cerebral perfusion (CP), 2) brain derived neurotrophic factor (BDNF), and 3) measures of cognitive function in subjects with late life major depression (LLMD). This research goal will be achieved by recruiting 38 individuals over the age of 65 with LLMD. The primary outcomes will be change in CP, change in BDNF, and change in cognitive measures from baseline to the end of 12 weeks of either therapy. We will also examine predictors of treatment outcome including severity of executive dysfunction, baseline BDNF concentrations, and baseline CP measures. The baseline neuropsychological testing, brain imaging, and depression assessment will be obtained in a companion study (PI S. Mackin; CHR #H42689-32681-01) that is IRB approved and is already in progress. In the current study a baseline serum BDNF level will be added to Dr. Mackin's protocol. Patients will then receive either 12 weeks of Problem Solving Therapy or antidepressant treatment with sertraline. Both treatments are evidence based and commonly administered in our clinic. Outcome variables will be measures of depression severity, the BDNF serum concentration, cerebral perfusion using a MRI arterial spin labeling (ASL) technique and cognitive changes in memory and executive dysfunction. This is a preliminary or pilot study. The primary objectives are to determine if the methods appear feasible and to determine if change in BDNF or CP occur after treatment and secondarily to determine if there are changes in cognitive functioning. The study is not powered to show differences between treatments. The hypotheses are 1) PST will result in increased perfusion in frontal regions of the brain but that frontal perfusion will not change with sertraline; 2)sertraline will result in an increase in BDNF but PST will not. Change in cognitive measures of memory, learning, and executive dysfunction will be examined on an exploratory basis.
Patients who have a functioning intracranial pressure-monitoring device (either a subarachnoid bolt, or an intraventricular catheter) in place, and are either sedated, intubated, and mechanically ventilated (i.e. in the NNICU), or are scheduled to undergo an operation or interventional neuroradiological procedure at the University of Virginia. Patients with a contraindication to TTE will be excluded. For patients in the NNICU, basic hemodynamic variables (systemic blood pressure, central venous pressure, etc.) will be collected. In addition, left ventricular performance (including estimates of LVEDV, LVESV, EF, FAC, and SV) will be assessed using TTE. Once these baseline data are recorded, the ITPR will be inserted in the ventilator circuit and activated to provide either -5 mm Hg or -9 mm Hg endotracheal rube pressure (ETP) (based on a randomization scheme). After the ITPR has been active for at least five minutes, the same intracranial, hemodynamic, and TTE data obtained above will be gathered. The ITPR will then be turned off for five minutes, and intracranial, hemodynamic, and TTE data will again be recorded. The ITPR will be activated a second time (-9 mm Hg or -5 mm Hg ETP, i.e. whichever value was not used previously), and after five minutes of use data will be recorded again. The ITPR will then be disconnected, data will be collected after waiting two minutes, and no further interventions will be made. ABG's will be obtained before and during the use of the device at each setting. This is a proof of concept/feasibility study designed to test the primary hypothesis that use of the ITPR will result in decreased intracranial pressure and increased cerebral perfusion pressure. The effect of the ITPR on secondary indicators of cardiac performance will also be examined. These include but are not limited estimates of ventricular end diastolic volume and pressure (LVEDV/P), ejection fraction (EF), left ventricular end systolic volume and pressure (LVESV/P), fractional area change (FAC), all of which will be assessed by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE).
The purpose of this study is to examine the effects of using dexmedetomidine (Precedex) in addition to the current standard-of-care for sedation.
The study hypothesizes that donepezil will have a positive impact on brain blood flow deficits in subjects with memory deficits and/or mild dementia and that improvements in brain blood flow will be accompanied by improvements in memory.
The purpose of this study is to use an experimental diagnostic tool(NIRS), combined with a known screening tool (cranial ultrasound), to analyze and evaluate cerebral blood flow and oxygenation, and determine if abnormal neurodevelopmental outcomes can be predicted and potentially improved upon in pediatric patients undergoing repair for congenital heart disease.
The purpose of the research is to see how simvastatin affects a substance in the body called beta-amyloid. Beta-amyloid is found in the brain and in the liquid around the brain and spinal cord. High amounts of beta-amyloid may be associated with a greater risk of getting Alzheimer's disease. This study will see if simvastatin can lower the amount of beta-amyloid in the spinal fluid. This study will also see if simvastatin affects memory and thinking, blood flow in the brain, and blood vessel function. The investigators hope that future studies show whether simvastatin might prevent memory loss and decrease the chance of developing Alzheimer's disease.
Alzheimer's disease (AD) often manifests as a memory disorder before dementia develops. Dementia is considered to be present when a person can no longer handle complex activities of daily living, such as managing finances. This study will investigate the relationship between changes in the ability to manage finances and brain perfusion, which will be measured using continuous arterial spin-labeling (an experimental MRI). Subjects will also undergo neuropsychological tests focusing on several types of memory and thought process, with special emphasis on semantic memory. An important question to be addressed is whether changes in function are better predicted by the neuropsychological tests or by the brain scan.
Traumatic brain injury (TBI) is among the leading causes of trauma death and disability in both civilian and military populations. The damage that occurs at the instant of trauma cannot be modified; the secondary injuries that occur afterward are the impediments to recovery and can be influenced by the physician. Cerebral ischemia is the most important secondary event that determines outcome following TBI. To minimize ischemic episodes once the patient has arrived at the hospital, most treatments are aimed at optimizing cerebral perfusion pressure (CPP). The cornerstones of these treatments include mannitol, to reduce intracranial pressure (ICP), and catecholamines, such as phenylephrine (PE), to increase mean arterial pressure (MAP), but these agents have undesired side effects. Nevertheless, once they lose potency, there are few alternatives. The main objective of this proposal to develop a new therapeutic option for CPP management in TBI patients using arginine vasopressin (AVP). AVP is the endogenous anti-diuretic hormone. It is FDA-approved for use in the diagnosis and treatment of diabetes insipidus, for the prevention and treatment of post-operative abdominal distention, and in abdominal radiography to dispel interfering gas shadows. It has been used off-label for several other conditions. There is minimal information on its therapeutic potential after TBI. The investigators have demonstrated that AVP during fluid resuscitation rapidly restored hemodynamics, CPP, and improves acute survival in a clinically-relevant model of TBI. The investigators observed similar short term benefits after chest and liver trauma. Nevertheless, AVP has actions that could mask any short term benefit. The investigators have already defined risks and benefits of AVP therapy, relative to PE, in four different clinically-relevant laboratory model. The investigators now plan to evaluate this new therapy relative to the current evidence-based guideline for CPP management in TBI patients. The working hypothesis is that the risk/benefit profile for AVP is equal, or superior to, PE at equi-effective doses for the management of CPP following TBI. A corollary is that a higher CPP can be safely tolerated with AVP vs catecholamines. THE INVESTIGATORS AIM TO: Determine whether AVP is safe and effective to maintain CPP = 60 mm Hg in TBI patients.
The specific aim of the research proposal in preterm infants with IVH and PHH who require placement of an Omaya reservoir or a shunt is to determine if decreasing ventricular volume improves, middle cerebral artery flow, cerebral oxygenation, and cortical neuronal electrical activity. To accomplish this aim, we will simultaneously perform the following evaluations prior to shunt placement or prior to and after routine CSF aspiration from reservoir in: 1. middle cerebral artery velocity time integral and resistive index using Doppler ultrasonography 2. cerebral oxygenation using near infrared spectroscopy (NIRS) 3. background neuronal electrical activity using an EEG. In addition, we will measure serial CSF concentration of neuroproteins, S100B, GFAP, NSE, TGF-ß, and IL-6, as evidence of ongoing neuronal damage and correlate the concentration with cerebral perfusion and activity as measured above.
There is a need to understand how long anesthetic drugs last in the brain during surgery on the ascending aorta or aortic arch. Drugs can have a prolonged effect when blood temperature is made cold therefore the influence of temperature needs to be studied. This type of surgery allows us to answer questions about how anesthetic drugs behave when they are given during a routine portion of surgery. Patients will be provided with anesthetic drugs during surgery while on a heart lung machine. After the drug is injected into the heart lung machine it will be delivered to the brain to provide more sleep and pain relief. Immediately after the injection of anesthetic drugs, blood samples will be taken from an existing intravenous line in the neck and plasma drug concentrations measured. This will help us to understand how long drugs last in the brain during this type of surgery.
The aim of the initial proposal was to evaluate, in the context of optimal medical management, the impact of a bedside system of cerebral perfusion pressure (CPP) information feedback on nursing moment-to-moment management of CPP, and the relationship of that management to patient functional outcome at discharge, 3 and 6 months. The primary hypothesis being tested is that Glasgow Outcome Score (GOS) 6 months post acute care discharge will be significantly better in those monitored with the continuous CPP display. In the second phase of the study the adult study will be extended to children to determine if there is a critical threshold for CPP in children following brain injury based on their outcome at 3, 6, and 12 months. The primary outcome measure is the GOS at 12 months post-injury. The GOS, Behavior Rating Inventory of Executive Function, and PedsQOL will also be assessed at 3, 6, \& 12 months, and the Adaptive Behavior Assessment System at 3 and 6 months post-injury. In addition, the researchers will examine variability and complexity of physiologic measures, such as blood pressure, recorded during the intensive care unit stay of adults and children enrolled in the study. The researchers will study the association of these measures with risk for secondary brain injury and ability to predict differences in outcome. The researchers will also assess the value individuals place on varying outcomes following brain injury.
This study uses magnetic resonance imaging to determine whether 3 weeks of repeated exposure to Acute Intermittent Hypoxia can improve brain blood flow or blood flow regulation in healthy adults.
The purpose of this study is to compare the changes measured by Somanetics Invos cerebral oximeter to the mean arterial pressure at brain level in patients having elective shoulder replacement surgery. The Somanetics Invos System measures and monitors the oxygen saturation (rS02) of blood in the brain tissues to help prevent brain injury or other complications. The investigators hypothesize that maintaining normocarbia and systemic mean arterial pressure at or above 70mmHg during general anesthesia in the beach chair position will decrease the number of cerebral deoxygenation events during the procedure.
The purpose of this study is to compare brain function after surgical circulatory arrest using either antegrade perfusion or retrograde perfusion.
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.
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.