Cortical Thickness Associated with Degree of Anemia in Children with Sickle Cell Disease

BACKGROUND AND PURPOSE: Sickle cell disease (SCD) is the most common inherited hemoglobinopathy that can cause multiorgan injury due to anemia, sickling, vaso-occlusive injury and vasculopathy. Silent cerebral infarct (SCI) is a common imaging abnormality identified in the brain in SCD. In this study, we assessed the impact of SCI and hemoglobin levels on brain morphometry in children with SCD.

MATERIALS AND METHODS: This retrospective study included pediatric patients with SCD and control sample of children without SCD. Morphometric analysis was performed on T1-weighted brain MR images. Morphometric measures include cortical regional gray matter volume, white matter volume, surface area, thickness, and gyrification index. The association of SCD and SCI with morphometric measurements were tested using a linear regression model accounting for age, sex, and race. Additionally, in children with SCD, the association of hemoglobin levels on morphometric measurements was assessed using a linear regression model.

RESULTS: There were 76 subjects including 43 with SCD and 33 controls. Of those with SCD, 20 had SCI. SCD was significantly associated with lower cortical gray matter volume in the left rostral middle frontal gyrus (p<0.001) and lower surface area in the rostral middle frontal gyrus (p<0.001), left frontal pole (p<0.001), and right insula (p=0.002). In children with SCD, hemoglobin levels were positively associated with increased mean cortical thickness in the left superior temporal gyrus (p<0.001) and both left and right cerebral hemispheres (p=0.002).

CONCLUSIONS: Hemoglobin levels were associated with cerebral cortical thickness in children with SCD.

ABBREVIATIONS: FDR＝ False discovery rate; OSA＝ Obstructive sleep apnea; SCD＝ Sickle cell disease; SCI＝ Silent cerebral infarcts