Epidemiology of Silent and Overt Strokes in Sickle Cell Disease

Study Summary

Sickle Cell Disease (SCD) is a rare disease occurring in an estimated 100,000 individuals, often poor and underserved, in the US. Silent and overt strokes contribute significantly to morbidity in adults with SCD, resulting in functional impairment, challenges with school and job performance, and premature death. Five NIH-funded randomized controlled trials have identified therapies to prevent silent and overt strokes in children with SCD, including monthly blood transfusion therapy (for preventing initial and recurrent strokes) and hydroxyurea (for preventing initial strokes). Despite the observation that at least 99% of children with SCD in high-income countries reach adulthood, and approximately 60% of adults will experience one or more strokes (\~50% with silent strokes and \~10% with overt strokes), no stroke trials have established therapeutic approaches for adults with SCD. For adults with SCD, inadequate evidence-based guidelines exist for secondary stroke prevention strategies. Applying stroke prevention strategies in children may not be effective for stroke prevention in adults with SCD, particularly given the high rate of co-morbidities. Identifying subgroups of adults with SCD and higher incidence coupled with the contribution of established stroke risk factors in the general population (smoking, diabetes, obesity, renal disease) will provide the requisite data required for the first-ever phase III clinical trials focused on secondary stroke prevention in adults.

Primary Outcome

Based on results of an MRI exam and a neurological exam, performed by a physician, the Neuroradiology Committee and the Neurology Committee will come to consensus on whether a silent stroke has occurred. Radiologically, silent stroke will be defined as a FLAIR T2W hyperintensity greater than 3 mm, visible in two planes. Neurologically, a silent stroke has no neurological sequelae.

Conditions Studied

Study Locations (4)