7 Clinical Trials for Various Conditions
In this prospective, single-arm, open-label, imaging and treatment study, the investigator will test the hypothesis that crizanlizumab will prevent the progression of silent cerebral infarcts in patients with sickle cell disease. Study participants will undergo brain MRI before initiation of crizanlizumab and at 6 and 30 months after starting crizanlizumab infusions. The crizanlizumab cohort will be compared to a matched, observational cohort of patients not receiving crizanlizumab.
Silent brain infarctions (SBIs) are a manifestation of covert cerebrovascular disease, without obvious clinical deficit, noted very often in patients presenting with a new stroke or new transient ischemic attack. SBIs are linked to a significant increase in risk for subsequent stroke and cognitive decline. However, no biomarker is currently available that can predict the recurrence of these subclinical lesions. Coated-platelets are a measure of platelet procoagulant potential significantly increased in patients with ischemic stroke or transient ischemic attack compared to unaffected controls. Higher coated-platelet levels are strongly associated with both the presence and number of SBIs. Among medications approved for preventing stroke recurrence, we identified clopidogrel as a pharmacological agent leading to a decrease in coated-platelet levels. In this project, we plan to evaluate if clopidogrel can decrease the rate of occurrence of new silent brain infarctions. The result will enhance the investigators understanding of the relationship between platelets and silent brain infarcts, leading to improved health care delivery and also potential targets for novel preventive pharmacological interventions.
The investigators' central hypothesis is that in patients with atrial fibrillation, anticoagulation with Apixaban reduces the rate of decline in cognitive function, when compared to Warfarin. The investigators also hypothesize that Apixaban reduces cognitive decline by reducing the rate of new cerebral infarction and cerebral microbleeds detected by cerebral MRI compared to warfarin.
The goal of this study is to determine the effectiveness of blood transfusion therapy for prevention of silent cerebral infarct (stroke) in children with sickle cell anemia.
Sickle cell disease (SCD) is the most common genetic disease, affecting about 25 million people worldwide. Approximately 150,000 Nigerian children are born each year with sickle cell disease (SCD), making it the country with the largest burden of SCD in the world. Recent advancements in care for children with SCA have translated into improved survival of children in both high and low-resource settings. However, more complications of SCD are seen in those who survive to adulthood. Silent cerebral infarcts (SCI) and strokes are among the most devastating complications of SCD, affecting 40% and 10% of children, respectively. The overall goal of this study is to extend the Investigator's successful capacity-building effort in the assessment of neurological morbidity in children with SCD living in northern Nigeria (Kano) to young adults with SCD living in the same region. About 50% of all adults with SCD live in Nigeria. Despite the high prevalence of SCD in Africa, the neurological morbidity is not well characterized, limiting opportunities for primary and secondary stroke prevention strategies. At least 50% of young adults with sickle cell anemia (SCA), the most severe form of the disease, will have SCIs and an estimated 10% will have strokes, based on studies in high-resource settings. In high-resource settings, screening for abnormal transcranial Doppler (TCD) velocities in children with SCA, coupled with regular blood transfusion has resulted in a 92% reduction of relative risk for strokes. Despite this effective strategy, regular blood transfusion therapy does not seem sustainable in sub-Saharan Africa due to shortages and the risk of transfusion transmissible infections. Additionally, there is a lack of evidence-based stroke prevention strategies in young adults with SCA, either in the high-income or in low-resource settings. Based on the foregoing, the Investigators propose to determine the prevalence of neurological injury (overt stroke, transient ischemic attacks, and silent cerebral infarcts) in young adults at the transition age from 16-25 years. The Investigators will also, for the first time, assess conventional risk factors of stroke in the general population to determine whether a different prevention strategy is required to reduce the incidence of neurological injury in this high-risk population.
This is a pilot study of hydroxyurea versus placebo to reduce central nervous system complications (abnormally fast blood flow to the brain, silent cerebral infarct or stroke) in young children with sickle cell disease. The investigators plan to identify children 12 to 48 months old without central nervous system complications and randomly assign 20 to treatment with hydroxyurea and 20 to treatment with placebo for 36 months. Neither the study doctors nor the participants will know which treatment they are receiving.
A silent stroke is a type of stroke that does not produce any severe symptoms, but may slightly affect memory or thinking abilities. Women who take hormone replacement therapy (HRT) may have a higher risk of experiencing a silent stroke than women who do not use HRT. This study will use magnetic resonance imaging (MRI) to determine the prevalence of silent strokes and other changes in brain tissue in women who participated in the Women's Health Initiative Memory Study (WHIMS), a study in which women received HRT, either as estrogen alone or as estrogen and progesterone combined, or placebo.