High incidence of cerebrovascular accidents in children and adults with SCD prior to the onset of primary stroke prevention with transcranial Doppler (TCD) and regular blood transfusion or hydroxyurea. Data from the 3647 children and adults with SCD followed prospectively from 1978 to 1988 in the Cooperative Study for Sickle Cell Disease cohort. The incidence rates of cerebrovascular accidents (CVA) were used to determine CVA-free survival curves. The estimated age at first CVA was significantly different for individuals with HbSS (SS) and HbSC (SC; P < .001). Chances of having a first CVA by 20 years of age, 30 years of age, and 45 years of age were estimated at 11%, 15%, and 24%, respectively, for HbSS patients and 2%, 4%, and 10%, respectively, for those with HbSC.¹  Reprinted from Ohene-Frempong et al with permission.¹