| dc.description.abstract | Children and adults with sickle cell anemia (SCA) are at significantly increased risk for deficits in multiple domains of cognitive functioning. Hemodynamic factors have been shown to be related to cognitive deficits in this population; however, no study has assessed cerebral oxygen extraction fraction (OEF) in relation to cognitive function. Further, studies have shown that problems with executive function in particular are associated with difficulties in coping with stress, and deficits are also associated with increased risk for emotional distress. The primary aim of Study 1 was to examine executive function in participants with SCA and healthy controls in relation to a novel MRI-derived measure of OEF and cerebral blood flow (CBF), while also controlling for other measures of pathophysiology and environmental factors. Results found that OEF and CBF were uniquely related to measures of executive function, and OEF remained a significant predictor of processing speed after controlling for history of infarct and environmental risks. Study 2 examined psychosocial correlates (secondary control coping, perceived control of stressors, and depressive symptoms) of cognitive function, with a focus on working memory. Results indicate that there were no significant direct or indirect associations between working memory and depressive symptoms through secondary control coping, and age did not moderate the association of working memory with coping or symptoms. Parent-reported perceived control, however, was positively related to depressive symptoms and had a significant interaction with secondary control coping, such that there was a significant negative association of secondary control coping with depressive symptoms only for low perceived control. Future research assessing hemodynamic predictors and psychosocial outcomes of cognitive function in sickle cell disease across the lifespan will be important for understanding these processes and designing biological and environmental interventions. | |
