Adults with sickle cell disease may perform cognitive tests as well as controls when processing speed is taken into account: a preliminary case-control study.
OBJECTIVE
This study aimed to: (1) evaluate cognitive function among adults with sickle cell disease using a computer-administered neuropsychological test; and (2) replicate previously identified differences in processing speed between patients with sickle cell disease and controls.


BACKGROUND
Previous evidence suggests that, compared with controls, adult patients with sickle cell disease have poorer cognitive functioning across most domains but the most significant deficits appear to be in the area of processing speed.


METHODS
Cross-sectional case-control study conducted from June 2008-June 2010.


METHODS
Cognitive functioning was measured using computerized, self-administered, neuropsychological tests among 31 patients with sickle cell disease and 17 controls matched for age, gender and race. The assessment averaged 30 minutes and scores were recorded for seven computerized tests: verbal and visual memory, finger tapping, symbol digit coding, Stroop test, shifting attention and continuous performance.


RESULTS
Patients with sickle cell disease scored 10·76 points lower on the CNS Vital Signs processing speed domain than controls. Although non-significant, patients scored 5·73 points lower on the full index than controls but after adjusting for processing speed, mean scores for patients were 3 points greater compared with controls. Differences in executive functioning and attention were not significant and memory did not differ between groups.


CONCLUSIONS
Using a brief, computer-administered 30-minute neuropsychological test, we were able to replicate previous findings showing a greater than 10-point deficit in processing speed among patients with sickle cell disease. When differences in processing speed are taken into account, patients perform equally well or better than controls on cognitive tasks.
Division of Hematology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA.
Regina D
RD
Crawford
School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Charles R
CR
Jonassaint
D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000523:psychology; D016022:Case-Control Studies; D003071:Cognition; D003072:Cognition Disorders; D003430:Cross-Sectional Studies; D006801:Humans; D009483:Neuropsychological Tests
case-control studies; computer neurocognitive testing; nursing; sickle cell disease