Regional oxygen extraction predicts border zone vulnerability to stroke in sickle cell disease

Melanie E. Fields, Kristin P. Guilliams, Dustin K. Ragan, Michael M. Binkley, Cihat Eldeniz, Yasheng Chen, Monica L. Hulbert, Robert C. McKinstry, Joshua S. Shimony, Katie D. Vo, Allan Doctor, Hongyu An, Andria L. Ford, Jin-Moo Lee. Neurology, Volume 90, Issue 13, 27 March 2018, Pages e1134-e1144 Read More

Abstract

Objective To determine mechanisms underlying regional vulnerability to infarction in sickle cell disease (SCD) by measuring voxel-wise cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen utilization (CMRO 2) in children with SCD. Methods Participants underwent brain MRIs to measure voxel-based CBF, OEF, and CMRO 2. An infarct heat map was created from an independent pediatric SCD cohort with silent infarcts and compared to prospectively obtained OEF maps. Results Fifty-six participants, 36 children with SCD and 20 controls, completed the study evaluation. Whole-brain CBF (99.2 vs 66.3 mL/100 g/min, p < 0.001), OEF (42.7% vs 28.8%, p < 0.001), and CMRO 2 (3.7 vs 2.5 mL/100 g/min, p < 0.001) were higher in the SCD cohort compared to controls. A region of peak OEF was identified in the deep white matter in the SCD cohort, delineated by a ratio map of average SCD to control OEF voxels. CMRO 2 in this region, which encompassed the CBF nadir, was low relative to all white matter (p < 0.001). Furthermore, this peak OEF region colocalized with regions of greatest infarct density derived from an independent SCD cohort. Conclusions Elevated OEF in the deep white matter identifies a signature of metabolically stressed brain tissue at increased stroke risk in pediatric patients with SCD. We propose that border zone physiology, exacerbated by chronic anemic hypoxia, explains the high risk in this region. © 2018 American Academy of Neurology.

Full Text

.

Posted on October 16, 2018
Posted in: HPAN, Lysosome, Neurodegeneration, Neurogenetics & Transcriptomics, Publications Authors: