Neuropsychological dysfunction and neuroimaging abnormalities in neurologically intact adults with sickle cell anemia.
BACKGROUND
Sickle cell anemia (SCA) is a chronic illness causing progressive deterioration in quality of life. Brain dysfunction may be the most important and least studied problem affecting individuals with this disease.


OBJECTIVE
To measure neurocognitive dysfunction in neurologically asymptomatic adults with SCA vs healthy control individuals.


METHODS
Cross-sectional study comparing neuropsychological function and neuroimaging findings in neurologically asymptomatic adults with SCA and controls from 12 SCA centers, conducted between December 2004 and May 2008. Participants were patients with SCA (hemoglobin [Hb] SS and hemoglobin level < or = 10 mg/dL) aged 19 to 55 years and of African descent (n = 149) or community controls (Hb AA and normal hemoglobin level) (n = 47). Participants were stratified on age, sex, and education.


METHODS
The primary outcome measure was nonverbal function assessed by the Wechsler Adult Intelligence Scale, third edition (WAIS-III) Performance IQ Index. Secondary exploratory outcomes included performance on neurocognitive tests of executive function, memory, attention, and language and magnetic resonance imaging measurement of total intracranial and hippocampal volume, cortical gray and white matter, and lacunae.


RESULTS
The mean WAIS-III Performance IQ score of patients with SCA was significantly lower than that of controls (adjusted mean, 86.69 for patients with SCA vs 95.19 for controls [mean difference, -5.50; 95% confidence interval {CI}, -9.55 to -1.44]; P = .008), with 33% performing more than 1 SD (<85) below the population mean. Among secondary measures, differences were observed in adjusted mean values for global cognitive function (full-scale IQ) (90.47 for patients with SCA vs 95.66 for controls [mean difference, -5.19; 95% CI, -9.24 to -1.13]; P = .01), working memory (90.75 vs 95.25 [mean difference, -4.50; 95% CI, -8.55 to -0.45]; P = .03), processing speed (86.50 vs 97.95 [mean difference, -11.46; 95% CI, -15.51 to -7.40]; P < .001), and measures of executive function. Anemia was associated with poorer neurocognitive function in older patients. No differences in total gray matter or hippocampal volume were observed. Lacunae were more frequent in patients with SCA but not independently related to neurocognitive function.


CONCLUSIONS
Compared with healthy controls, adults with SCA had poorer cognitive performance, which was associated with anemia and age.
Vichinsky
Elliott P
EP
Department of Hematology/Oncology, Children's Hospital & Research Center Oakland, 747 52nd St, Oakland, CA 94609, USA. evichinsky@mail.cho.org
Neumayr
Lynne D
LD
Gold
Jeffrey I
JI
Weiner
Michael W
MW
Rule
Randall R
RR
Truran
Diana
D
Kasten
Jeffrey
J
Eggleston
Barry
B
Kesler
Karen
K
McMahon
Lillian
L
Orringer
Eugene P
EP
Harrington
Thomas
T
Kalinyak
Karen
K
De Castro
Laura M
LM
Kutlar
Abdullah
A
Rutherford
Cynthia J
CJ
Johnson
Cage
C
Bessman
Joel David
JD
Jordan
Lanetta B
LB
Armstrong
F Daniel
FD
D000328:Adult; D000367:Age Factors; D000740:Anemia / Q000150:complications* / Q000209:etiology; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000503:physiopathology*; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000150:complications*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D002534:Hypoxia, Brain / Q000150:complications / Q000209:etiology; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests
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