View clinical trials related to Brain Ischemia.
Filter by:To perform an exploratory single center randomized study that will form the basis for a larger scale, more definitive randomized clinical trial to determine the optimal time after stroke for intensive motor training. The investigators will perform a prospective exploratory study of upper extremity (UE) motor training delivered at higher than usual intensity at three different time points after stroke: - early (initiated within 30 days) - subacute/outpatient (initiated within 2-3 months) - chronic (initiated within 6-9 months) The control group will not receive the therapy intervention during the 1-year study. Outcome measures will be assessed at baseline, pre-treatment, post-treatment, 6 months and one year after stroke onset. Compared to individuals randomized during the outpatient (2-3 months after stroke onset) or chronic (6-9 months after stroke onset) time points, participants randomized to early intensive motor training will show greater upper extremity motor improvement measured at one year post stroke.
The primary objective of HOPE is to improve the accuracy of outcome prediction in anoxic-ischemic encephalopathy following cardiac arrest by bringing under close scrutiny some of the existing methods used for this purpose (e.g. somato-sensory evoked potentials). HOPE is the first multicenter prospective cohort study on coma prognosis to control for the effect of a possible self-fulfilling prophecy at the ICU and to cover the acute and neurorehabilitation phases with a long-term follow-up longer than the usual three or six months.
Introduction Aneurysmal subarachnoid hemorrhage (aSAH) is bleeding around the under surface of the brain caused by rupture of an aneurysm arising from a blood vessel. Stroke may occur in approximately one third of patients as a result of narrowing of the blood vessels around the brain, following aSAH. One theory as to why this may happen is because bleeding around the base of the brain damages particular cells (neurons) that control blood flow around the rest of the brain. These neurons may control blood flow by releasing a neurotransmitter called Acetyl Choline (ACh). Our hypothesis is that damage to these neurons may prevent the production of ACh, which then causes reduced blood flow and stroke if left untreated. By stimulating these neurons, we aim to investigate whether it is possible to improve the blood flow around brain and ultimately prevent strokes in patients following subarachnoid haemorrhage. Donepezil, a drug widely used in dementia, inhibits the brain's natural break down of ACh. We predict that by increasing the amount of Ach in these neurons, donepezil may improve blood flow to the brain, reducing the chance of developing stroke. Trial Protocol All patients admitted to St George's hospital with a confirmed aneurysmal subarachnoid haemorrhage between the ages of 18 and 85 years old will be invited to participate in the trial. The protocol has been designed to take place around the patients' aneurysm treatment, which is performed under general anesthesia (GA). Recruited participants will be anesthetized for their aneurysm treatment and then enter the study. All trial participants will have a Xenon CT scan under GA to assess brain blood flow prior to having treatment of their aneurysm. Patients randomized to donepezil treatment will receive a loading dose of 20mg via a feeding tube immediately after their Xenon scan. Patients in the control group will not receive the drug. All patients in the trial will undergo repeat Xenon perfusion scanning under GA between 3 and 4 hours after their first scan, which coincides with the completion of their aneurysm treatment. Those in the donepezil group will then receive a daily dose of 5 mg for a period of 21 days. All aspects of care other than those related to the trial will be the same as for any other subarachnoid haemorrhage patients. Patients (or their legal representative for those unable to consent) will be able to decline participation in the trial or withdraw at any point.
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.
The purpose of this study is to measure cerebral oxygenation and cardiac output of total shoulder replacement patients undergoing general anesthesia (GA) and positive-pressure ventilation (PPV). We hypothesize that cerebral desaturation occurs frequently during GA with PPV, but is rare during GA and spontaneous ventilation. We also hypothesize that cardiac output usually is well maintained under GA in the sitting position when epinephrine is used, but that decreased cardiac output increases the risk of cerebral desaturation.
Coronary artery disease (CAD) is the leading cause of death worldwide. Patients with severe CAD are often treated with coronary artery bypass grafting (CABG). Novel treatment strategies need to be pursued to respond to the continuous increase in the risk profile of contemporary CABG patients. Surgical myocardial revascularization is commonly performed with the use of cardiopulmonary bypass (CPB). Neurological impairment following CABG may take on the form of a new-onset motor deficit or postoperative cognitive dysfunction. The former is rare, but potentially devastating. Conversely, declines in attention, memory and fine motor skills can frequently be documented. Ischemic preconditioning is a phenomenon of an endogenous protective response to organ ischemia, which is triggered by brief cycles of nonlethal ischemia and reperfusion in tissues known to be more resistant to ischemic insults. In clinical practice remote ischemic preconditioning (RIPC) is achieved by inflicting short periods of ischemia with intermittent restitution of flow to the upper extremity. This intervention has been shown to be effective in the reduction of myocardial injury in cardiac surgical patients. The hypothesis tested in this research proposal is that RIPC will decrease the extent of postoperative neurological injury following CABG. In this research project, 70 patients scheduled for an elective CABG will be recruited at a single center. They will be randomly allocated to either undergo RIPC (intervention arm) or a sham procedure (control arm). Inflating a blood pressure cuff to 200 mmHg for 5 min will induce RIPC, thereby inducing a brief period of ischemia. This will be followed by a 5-minute arm reperfusion. In total, three cycles of arm ischemia and reperfusion will be induced in this fashion. All patients will undergo pre- and post-procedural magnetic resonance imaging (MRI) of the brain, as well as neurocognitive testing. The array of MRI tools that will be used for the quantification of brain injury will include fluid attenuated inversion recovery, diffusion weighted and susceptibility weighted imaging, coupled with resting state functional MRI. The investigators aim to determine whether RIPC can reduce the adverse impact of CPB on neurological outcome as evaluated by MRI detectable brain ischemia and neurocognition.
To compare the effectiveness of unilateral pulmonary collapse (right lung) to bilateral pulmonary collapse for cardiac de-airing in open left-sided heart surgery.
Rationale The only proven therapy for acute stroke is tPA within 4.5 hours of symptom onset. This is the standard of care for patients presenting to our hospital within that time frame. Thrombolysis outside the 4.5 hour window is considered only on experimental or compassionate grounds. Tenecteplase (TNK) is a genetically modified variant of tPA that has many theoretical advantages in acute stroke. Studies show that systemic plasminogen activation is higher after tPA administration, relative to TNK and this is associated with an increased risk of bleeding events. Imaging cerebral blood flow (CBF) with MRI (perfusion weighted imaging-PWI) and CT perfusion (CTP) can be performed routinely with standard clinical scanners. Patients with evidence of large volumes of tissue with low CBF, that is also structurally intact, as demonstrated by either normal signal on Diffusion weighted imaging (DWI) or normal cerebral blood volume (CBV) are considered to have penumbral patterns. Patients with penumbral patterns appear to be the ideal candidates for thrombolytic therapy, regardless of time from onset. Study Hypotheses 1. The primary aim of this study is to demonstrate the feasibility and safety of TNK based thrombolysis in ischemic stroke patients presenting 4.5-24 hours after symptom onset. 2. It is hypothesized that treatment with TNK in patients with penumbral patterns will be associated with reperfusion, early neurological improvement and penumbral tissue salvage. Study Design The study is planned as an open label feasibility and safety study of acute treatment with TNK in ischemic stroke patients with penumbral patterns evident on advanced MRI or CT perfusion sequences. Study Outcomes The primary outcome of this study is a safety endpoint, specifically the frequency of symptomatic hemorrhagic transformation evident on MRI or CT images on 24 h or day 5 scans. The ECASS II system for rating hemorrhagic transformation will be applied to all GRE/SWI images Significance Current treatment paradigms have not permitted success of tPA to be extended beyond narrow and limiting therapeutic window of 4.5 hours. Clearly, more effective patient selection criteria are required. Penumbral imaging is biologically plausible, practical and has been shown to be predictive of outcome. Application of these imaging techniques to the acute stroke population is the most promising strategy for extending the therapeutic window and for introducing superior thrombolytic agents.
The objective of this trial is to visualize blood brain barrier function and metabolic changes in the first days after ischemic stroke with new investigational MRI sequences.
This study examines the effect of inhaled xenon gas in the treatment of newborn infants with hypoxic-ischemic encephalopathy (HIE) in combination with cooling, which is the standard treatment for this condition. The hypothesis is that the xenon + cooling combination will produce better neuroprotection than the standard treatment of cooling alone.