Researchers at Cincinnati Children's Hospital and several additional centers in the US and UK studied the incidence of acute silent cerebral ischemic events (ASCIEs) in MRIs of children with asymptomatic sickle cell anemia (SCA). ASCIEs were detected in 1.3% of MRIs (10 of 771) in 652 children (mean age 10 years), with an incidence of 47.3 events per 100 patient-years. At follow-up MRIs in 2 of 10 children with ASCIEs, only 1 had silent cerebral infarction correlating with the location of a previously detected ASCIE. Children with SCA are at risk of frequent ongoing chronic, intermittent, cerebral ischemic events, sometimes reversible. 
COMMENT. The authors conclude that children with SCA experience clinically silent cerebral ischemia far more frequently than previously recognized. The brain in SCA is at constant threat of ischemic injury. The Nashville experience with neurologic injury in SCA finds that the specific morbidity includes a decrement in general intellectual abilities, poor academic achievement, progression in overt stroke, and new SC infarct despite regular blood transfusion therapy.