Neurocognitive screening with the Brigance Preschool screen-II in 3-year-old children with sickle cell disease

Background: Neurocognitive deficits have been described in school age children with sickle cell disease (SCD), even in the absence of stroke or silent infarcts. However, the age of onset and factors contributing to this problem have not been well studied. We hypothesized that in children with SCD the failure rate with Brigance screening would be higher than in the normal population. Methods: We reviewed retrospectively the Brigance Preschool Screen-II test results in 3-year-old children with SCD. Findings were correlated with hemoglobinopathy genotype, hemoglobin level, transcranial Doppler ultrasound (TCD) velocities, and treatment with hydroxyurea, as well as with psychosocial factors. Results: Eighty-eight children with SCD followed by the St. Jude Sickle Cell Center (mean age 3.5 years) had neurocognitive screening during their regular clinic visits. Forty-four (50%) children had scores below the normal cut-off value for their age (twice the national failure rate of 25%). Failures were associated with less parental education (P=0.005 for maternal and P=0.03 for paternal education levels) and with speech deficits (P=0.01), but were not associated with sickle cell genotype or hemoglobin concentration. Conclusion: These preliminary data suggest that psychosocial factors may have more profound effects on early childhood development than disease-related factors in this group of young sickle cell patients. A larger prospective study with appropriate controls is warranted to validate these findings, which have implications for the etiology and prevention of neurocognitive decline in children with SCD.