Brain MRI/MRA Findings after Hydroxyurea Treatment in Children with Sickle Cell Anemia

Background: Up to 40% of children with sickle cell anemia (SCA) will have abnormalities on brain imaging due to their hematologic disorder, much of which is subclinical. Common abnormalities on brain magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) include leukoencephalopathy from microvascular ischemic insult and vascular stenosis from endothelial damage. Silent cerebral ischemic insults are progressive; further neurologic abnormalities, including overt stroke, are more common among children with ischemic findings on MRI compared to children without them. Furthermore, poor performance on neuropsychological testing, lower IQ, and higher rates of grade retention are common in children with SCA and cerebral ischemic disease. The effect of hydroxyurea treatment on the development and progression of vascular stenosis and leukoencephalopathy is unclear. This study aimed to longitudinally evaluate the development of intracerebral abnormalities through serial MRI/MRA in children with SCA (HbSS and HbSβ0-thalassemia) who receive long-term therapy with hydroxyurea.