| Sickle-cell disease (SCD) is the most common cause of stroke in children, which follows the exhaustion of vasodilatory capacity known as cerebrovascular reserve. Cerebrovascular reserve may be impaired in SCD due to chronic anemia and endothelial dysfunction, which may place SCD children at an increased risk for stroke. Therefore, we set out to assess cerebrovascular reserve in children with SCD using MR-based measures of cerebrovascular reactivity (CVR). We demonstrated that SCD children with a greater severity of anemia have higher cerebral blood flow and lower CVR. In addition, we have shown that SCD children on hydroxyurea or transfusion treatments have reduced severity of anemia and greater CVR than untreated patients. These results suggest that SCD children with greater severity of anemia access more of their cerebrovascular reserve in an attempt to maintain adequate oxygen supply and hydroxyurea or transfusion-treated patients have increased reserve, which may be beneficial in stroke prevention. |
