Clinical Research Directory

Stroke Prevention in Young Adults 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.

Prevalence of Attributable Etiology and Modifiable Stroke Risk Factors in Patients With Covert Brain Infarctions

The CBI registry is a prospective, interdisciplinary, multimodal observational registry of patients with covert brain infarction. Methods: A standardized workup in analogy to manifest ischemic stroke including cerebral MRI, long-term rhythm monitoring (3 x 7 days ECG), echocardiography, laboratory work-up and risk factor assessment as well as noninvasive angiography of the cervical and intracranial arteries will be performed.

Incidence of Silent Atrial Fibrillation in Patients With Clinically Silent Brain Ischemic Lesions

Arterial Fibrillation (AF) is well-recognized as a cause for cryptogenic Acute Ischemic Stroke (AIS) and is associated with Silent Brain Infarction (SBI). However, the role of AF in the formation of lesions (SBIs) is less well established than its role in AIS and needs clarification. The investigators hypothesize that continuous rhythm monitoring will yield a similar incidence of AF diagnosis in patients with SBI as compared to patients with cryptogenic AIS. The primary objective is to assess the cumulative incidence of AF diagnosis at 24 months in patients with SBI.