Sickle cell anemia, although best characterized by chronic anemia, pain, and vascular occlusion, is also associated with strokes and cognitive problems in children, and magnetic resonance imaging is key to proper monitoring and managing of the disease, researchers in China reported.
Researchers at the Xuzhou Children’s Hospital highlighted the neurological complications of sickle cell disease in their review article, “Magnetic resonance imaging in pediatric sickle cell anemia,” published in Experimental and Therapeutic Medicine.
Patients with sickle cell anemia often have blood vessel occlusion and impaired blood flow, which can lead to severe such complications as pulmonary disease, growth restriction, and stroke.
Strokes, either caused by infarction, where the arterial or venous blood flow is compromised by blood clots, or hemorrhage, can be common in children with sickle cell anemia. The onset of strokes is most often seen in the first 10 years of life, but can occur as early as 6 to 12 months of age.
Major risk factors associated with ischemic stroke in these patients are low hemoglobin, high white blood cell counts, hypertension, previous transient ischemic attack (similar to a stroke but associated with a shorter and reversible neurological event), a history of acute chest syndrome, and low hemoglobin oxygen saturation.
Silent cerebral infarction (SCI), also known as ‘silent’ stroke, is the most common type of stroke in young sickle cell patients, with evidence of SCIs in 35 percent of these children, the researchers wrote. SCI can only be diagnosed using magnetic resonance imaging (MRI).
Chronic complications of sickle cell anemia, such as strokes, are managed in the short term through blood transfusions. The transfusions improve blood flow and increase its oxygen-carrying capacity, working against cerebrovascular events. However, they are associated with other complications, such as iron overload and blood hyperviscosity, and raise the risk of transfusion with contaminated blood.
Other strategies for disease management in children include administration of hydroxycarbamine, or hydroxyurea, which inhibits the polymerization of hemoglobin molecules. Bone marrow transplants are the only successful treatment for sickle cell anemia thus far, but such an approach is used only for the severely ill and children typically need a matching sibling donor.
Parents and caretakers need to be educated early about the disease and its aspects to help reduce the risks of vaso-occlusive episodes. Similarly, patients must be taught about the limitations of their disease as they become independent to best prevent or manage neurological events.
A key step, however, is monitoring these patients with imaging techniques, such as MRI, for signs of cerebral infarction. Recent studies have shed some light on the vessels that are more commonly affected in sickle cell patients, knowledge that may lead to targeted therapies.