Sickle cell disease may affect brain function in adults

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SICKLE cell disease may affect brain function in adults who have few or mild complications of the inherited blood disease, according to results of the first study to examine cognitive functioning in adults with sickle cell disease. The multicenter study, funded by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, compared brain function scores and imaging tests in adult patients with few sickle cell complications with results in similar adults who did not have the blood disease.
Researchers report that the brain function scores in sickle cell patients were, on average, in the normal range. However, twice as many patients as healthy adults (33 percent versus 15 percent) scored below normal levels.
Those who were more likely to score lower were older and had the lowest levels of hemoglobin, the protein in red blood cells that carries oxygen in the blood, compared to sickle cell participants who scored higher. Findings from brain magnetic resonance imaging scans did not explain differences in scores.
Researchers at 12 sites within the NHLBI-supported Comprehensive Sickle Cell Centers conducted the study. Their results are published in the May 12 issue of the Journal of the American Medical Association. An editorial accompanies the article. “This study suggests that some adult patients who have sickle cell disease may develop cognitive problems, such as having difficulty organizing their thoughts, making decisions, or learning, even if they do not have severe complications such as stroke related to sickle cell disease,” said NHLBI Acting Director Susan B. Shurin, M.D.
“Such challenges can tremendously affect a patient’s quality of life, and we need to address these concerns as part of an overall approach to effectively managing sickle cell disease.”
Researchers tested cognitive functioning of 149 adult sickle cell disease patients (between the ages of 19 and 55) and compared them to 47 healthy study participants of similar age and education levels from the same communities.
All of the participants were African-American. More sickle cell disease patients scored lower on measures such as intellectual ability, short-term memory, processing speed, and attention, than participants in the healthy group.
The sickle cell disease participants did not have a history of end-organ failure, stroke, high blood pressure, or other conditions that might otherwise affect brain function.