FRIDAY, Dec. 2 (HealthDay News) -- Children with sickle cell
disease, an inherited blood disorder, who also have high blood
pressure and/or anemia are at increased risk for so-called "silent
strokes," according to a new study.
Silent strokes, which cause no symptoms, "are typically seen in
older adults, and these findings give us additional insight into
why they tend to occur so often in children with sickle cell
disease," senior study investigator Dr. James Casella, director of
hematology at Johns Hopkins Children's Center, said in a center
Casella and his colleagues performed MRI brain scans on 814
children with sickle cell disease, aged 5 to 15, and found that 31
percent of them had suffered silent strokes. None of the children
had a history of strokes or seizures, and none showed any signs of
stroke at the time of the study.
After examining the children's medical histories, the
researchers concluded that anemia and high blood pressure
individually increased the risk of silent stroke in the study
participants, but the combination of the two carried the highest
Among these sickle cell patients, those with the highest
systolic blood pressure (the top number in their blood pressure
reading) was above 113 and the lowest hemoglobin (below 7.6 grams
per deciliter) had a nearly four times greater risk of silent
stroke than those with the lowest blood pressure and highest
hemoglobin. Hemoglobin is the protein in red blood cells that
carries oxygen. Anemia is defined by low levels of hemoglobin.
Compared to children with the lowest blood pressure readings,
those with the highest blood pressure had a 1.7 times greater risk
of silent stroke. And the risk was more than doubled for kids with
the lowest hemoglobin levels versus kids with the highest
hemoglobin levels, the investigators found.
The researchers said their findings highlight the need to
identify children with sickle cell disease who have early signs of
anemia and high blood pressure, both of which are modifiable risk
factors. The findings may also lead to new treatments for sickle
The study was published online Nov. 17 in the journal
While extremely rare in children overall, stroke is a common
complication in children with sickle cell disease. Nearly 100,000
people in the United States have sickle cell disease. The disease,
inherited from both parents, causes red blood cells to take the
shape of crescents or sickles, and results in less oxygen being
delivered to the body's tissues. These fragile cells can interrupt
blood flow when they get stuck in small blood vessels. Patients
with sickle cell disease require ongoing treatment, according to
the U.S. National Institutes of Health, which funded the study.
The Nemours Foundation has more about
sickle cell disease.