View clinical trials related to Stroke.
Filter by:The purpose of this study is to determine whether aspirin or warfarin is more effective in preventing stroke in patients with intracranial stenosis.
The African-American Antiplatelet Stroke Prevention Study is designed to prevent recurrent strokes by administration of aspirin or ticlopidine. The study also provides community information on reducing risk of stroke and recognizing the symptoms of stroke. The study involves more than 50 participating hospitals located throughout the United States. Study medication is provided free of charge, and a transportation stipend is available for those in need.
Effective treatment and prevention strategies for childhood stroke and porencephaly can only be developed once the causes are understood. There is increasing evidence that inherited and acquired coagulation abnormalities alone or in combination with environmental factors, predispose to arterial and venous thrombosis. Inherited abnormalities of factor V Leiden, prothrombin, protein C, protein S, and antithrombin III may account for many of these thromboses. At present there is little information on the existing distribution of these coagulation anomalies in children with thrombosis. Recent reports also suggest that these clotting abnormalities may be responsible for some instances of intracranial hemorrhage, porencephaly, cerebral palsy and fetal death. This study will measure the frequency of several coagulation factor abnormalities (factor V Leiden, prothrombin 20210A, protein C, protein S, antithrombin III, and antiphospholipid antibodies) in children with a history of porencephaly and stroke, and will compare these to the prevalence of these mutations in population controls and family members. We will also describe the exogenous conditions which in concert with these coagulation factors, may have led to the development of thrombosis in these children....
This project will investigate the evolution of treated and untreated stroke in patients recruited from the collaborative brain stroke program between NINDS, CC, and Suburban Hospital. The study will use anatomical and functional imaging techniques with emphasis on the acute and subacute stage (less than one month) of the disease. As the availability of new therapeutic options for the management of acute brain stroke increases, the need to define the evolution of the disease becomes paramount, particularly as therapeutic windows, defined by known and perhaps yet undiscovered parameters, may exist. Defining these parameters will be based on state-of-the-art imaging technology with the potential of clarifying the division between ischemia (reversible damage) and infarction (irreversible). Measures of lesion size and distribution along with vascular morphology, diffusion, perfusion, flow-related, and metabolic measures will be obtained over time. We foresee these measurements will significantly develop our understanding of cerebral ischemia and introduce diagnostic and quantitative tools to guide therapy and measure its efficacy.
The purpose of this study is to determine if giving amphetamines along with standard rehabilitation speeds motor recovery after a stroke. In addition, if motor recovery is improved, the study will also identify the areas of the brain involved with the recovery. Researchers will use motor function ratings, PET scans, functional MRI (fMRI), electroencephalographs, and transcranial magnetic stimulation (TMS) to evaluate patients. Patients participating in the study will be placed in one of two groups; 1. Patients receiving dextroamphetamine and routine Rehabilitation Medicine 2. Patients receiving a placebo "sugar pill" and routine Rehabilitation Medicine Patients that have improved motor recovery will undergo neuroimaging and neurophysiological studies to identify areas of the brain involved.
Fabry's disease a genetic disorder (X-linked recessive) due to the absence of the enzyme alpha-galactosidase A. The disease is characterized by abnormal collections of glycolipids in cells (histiocytes) within blood vessel walls, tumors on the thighs, buttocks, and genitalia, decreased sweating, tingling sensations in the extremities, and cataracts. Patients with Fabry 's disease die from complications of the kidney, heart, or brain. The objective of this study is to test the belief that patients with Fabry's disease have a problem with blood vessels becoming larger. The walls of blood vessels contain muscles that when they relax the vessel becomes larger. This process is referred to as vasodilation. It is controlled by a substance released by cells in blood vessels called EDRF (endothelium-derived relaxing factor). Several drugs can affect vasodilation. Researchers believe some drugs may work by blocking the affect of EDRF. Researchers would like to test the effects of these drugs on the blood vessels of normal volunteers and patients with Fabry's disease.
The purpose of this study is to investigate the physiology associated with plasticity of the motor system. Plasticity refers to the process by which neighboring brain cells assume the responsibilities of damaged or diseased brain cells. The mechanisms behind this process are unknown. However, researchers have several theories about how plastic changes take place. Possible explanations include the growth of new connections between brain cells and the use of previously unused connections. Researchers plan to use transcranial magnetic stimulation and drug intervention in order to determine the mechanisms responsible for specific types of plasticity. Previous studies have shown that certain drugs can affect the mechanisms involved in these changes. By using one drug at a time, researchers plan to evaluate the role of each of several different mechanisms in brain reorganization.
Researchers have been interested in the changes associated with motor function in humans after suffering a stroke. Presently, the mechanism by which a person recovers motor function following a stroke is poorly understood. There is little information available about the areas of the brain involved in the recovery of limb function. Recently, a new set of techniques have been developed that may be useful for reducing the physical impairment often associated with strokes. The best way to identify the areas of the brain associated with regaining function is to test patients before, during, and after function is regained. This study will compare two therapies and determine which is better at improving recovery of motor function. The first technique involves immobilizing the functional limb and actively training the affected dysfunctional limb. The second technique involves no immobilization, and passive movement of the affected limb. Results from this study will indicate which of the two therapies is better at improving motor function. Additional diagnostic tests will help to identify changes in brain function associated with recovered use of affected limbs.
Early studies have shown that the immune system may play a role in the development of strokes. Conditions such as high blood pressure, high cholesterol, diabetes, and old age can activate the immune system and increase the risk of developing hardening of the arteries (atherosclerosis) and damaged blood vessels. Researchers will attempt to characterize factors that may contribute to atherosclerosis and stroke by measuring certain components of the immune system, cytokines and leukocyte activation. Measurements will be taken from patients that are considered to be stroke prone and from patients without risk factors for the development of stroke. Researchers will measure the immune system components at the beginning of the study, at six months, and at the one-year completion of the study. The study will attempt to determine; I) If patients with risk factors for stroke have an increased activation of the immune system II) If patients with risk factors for stroke that are symptomatic have higher levels of immune system activation compared to patients who do not have symptoms III) If patients with increased activation of the immune system have accelerated hardening of the arteries (atherosclerosis)
Positron Emission Tomography (PET) is a technique used to investigate activity in areas of the brain. The PET technique allows researchers to study the normal processes in the brain (central nervous system) of normal individuals and patients with neurologic illnesses without physical / structural damage to the brain. When a region of the brain is active, it uses more fuel in the form of oxygen and sugar (glucose). As the brain uses more fuel it produces more waste products, carbon dioxide and water. Blood carries fuel to the brain and waste products away from the brain. As brain activity increases, blood flow to and from the area of activity also increases. This is known as regional cerebral blood flow (rCBF). Knowing these facts, researchers can use radioactive water (H215O) and PET scans to observe what areas of the brain are receiving more blood flow. In this study researchers plan to investigate the changes in regional cerebral blood flow (rCBF) as patients participate in different activities. The activities are designed to stimulate the areas of the brain responsible for voluntary motor activity and sensation. By comparing the results of PET scans performed in different conditions, researchers can locate regions of the brain responsible for specific tasks. This study should provide new information about voluntary movements in humans and the preparation involved in controlling them.