title: Hemodynamic responses to visual stimulation in children with sickle cell anemia.
abstract: Blood oxygenation level-dependent (BOLD) and cerebral blood flow (CBF)-based functional magnetic resonance imaging (fMRI) were used to measure primary visual cortex responses to photic stimulation in 23 children (12.4  ±  0.7 years old) with sickle cell anemia (SCA) and 21 clinical controls (11  ±  1.0 years old). The objectives were to investigate the effect of SCA on detection of brain activation with fMRI and to explore the relationship between fMRI responses and global cognitive function. The BOLD responses were diminished in children with SCA. Clinical indicators of disease severity were greatest in patients without detectable visual cortex activation, but blood hemoglobin concentration and resting CBF were not predictive of BOLD signal amplitude in the SCA patients. Unexpectedly, the BOLD signal amplitude was positively associated (r(s)  ≥  0.8, p  ≤  0.05) with Wechsler Abbreviated Scale of Intelligence scores, suggesting that fMRI may help clarify medical, hemodynamic, and neural factors that mediate adverse effects of SCA on neurocognitive function.
authors: Department of Radiological Sciences, St. Jude Children's Research Hospital, MS 220, 262 Danny Thomas Place, Memphis, TN 38105, USA.
authors: Ping
authors: P
authors: Zou
authors: Kathleen J
authors: KJ
authors: Helton
authors: Matthew
authors: M
authors: Smeltzer
authors: Chin-Shang
authors: CS
authors: Li
authors: Heather M
authors: HM
authors: Conklin
authors: Amar
authors: A
authors: Gajjar
authors: Winfred C
authors: WC
authors: Wang
authors: Russell E
authors: RE
authors: Ware
authors: Robert J
authors: RJ
authors: Ogg
mesh_terms: D000465:Algorithms; D000755:Anemia, Sickle Cell / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D002648:Child; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology; D014888:Wechsler Scales
chemical_list: D010100:Oxygen