Executive function in patients with sickle cell disease

Abstract

The pathological sequelae of Sickle Cell Disease extend to multiple body systems. This study intended to extend the findings of a small body of literature suggesting neuropsychological deficits in children with SCD, by examining the performance of 21 adult SCD patients and 16 sibling/acquaintance controls ages 19 to 41 years, free of frank neurological impairment, Mental Retardation, psychiatric disturbance, narcotic medication, or specific hematological therapy, to test the following hypotheses: (1) that SCD patients would show deficiency on executive tasks relative to controls, (2) that SCD patients and controls would not differ on tasks tapping posterior cortical functions, such as I.Q., and (3) that age would be negatively associated with performance on executive tasks.;The study battery included tasks chosen for specific sensitivity to executive function as follows: Rey-Osterrieth Complex Figure Test, Design Fluency Test, Wisconsin Card Sorting Test, Stroop Color/Word Test, as well as a range of cognitive tasks considered to be more specifically sensitive to the functioning of the posterior cortex, including the following: abbreviated WAIS-R, WRAT-R Reading, Token Test, Sentence Repetition, Controlled Oral Word Association, WMS-R-Logical Memory and Visual Reproduction, Selective Reminding Test, Stroop Word and Color Tests, and Purdue Pegboard.;The study findings indicated strong support for the first two hypotheses with no significant group differences indicated for the nonfrontal measures included and MANOVA analysis of the executive tasks indicating significant findings of deficient performance of the SCD group in comparison to the controls. No age related association with executive task performance nor I.Q. was demonstrated. In addition, post hoc analysis of the SCD patients showed no significant association between disease severity (measured by hospitalization frequency) and executive task performance nor I.Q. The findings suggest specific dysfunction associated with frontal lobe function.