Neurocognitive deficits in children with sickle cell disease are associated with the severity of anemia

Background: Although neurocognitive deficits in children with sickle cell disease (SCD) have been well documented, the etiology of these deficits has not been completely clarified. The aim of this study was to investigate the association of laboratory markers of disease severity and radiological parameters with neurocognitive functioning in children with SCD. Design and Methods: Participants were 37 children with SCD ((HbSS or HbS-β⁰-thalassemia) aged 6-18 years. All participants underwent extensive neurocognitive assessment. Further data (TCD values, laboratory test results, and MRI data) were obtained from medical charts. Associations were analyzed by hierarchical regression analysis. Results: Hemoglobin was associated with a decrease in verbal short-term memory. There was no association between TCD velocities and neurocognitive functioning, when controlled for age. Children with silent infarcts did not differ from children with normal MRI in neurocognitive functioning. Children with right-left asymmetries in cerebral blood flow as measured by continuous arterial spin labelling (CASL) MRI had better sustained attention than children without asymmetries. Conclusions: Neurocognitive deficits are associated with the severity of anemia, indicating reduced oxygen delivery to the brain as an etiological mechanism. This implies that children with SCD and normal MRIs may still suffer from neurocognitive impairments, possibly affecting their academic development and full participation in society.