Sickle cell disease patients experienced sufficient oxygen delivery at rest, but achieved this only by marked increases in resting cerebral blood flow in a study involving 91 individuals. This limited their ability to further increase flow in response to stress.

Participants included patients with sickle cell disease (n=37), ethnicity matched controls (n=38), and patients with anemia of non-sickle origin (n=16). Investigators measured cerebral blood flow via MRI of the carotid and vertebral arteries. Among the results:

• Cerebral blood flow increased inversely to oxygen content.

• Brain oxygen delivery was normal in all groups.

• Brain composition was a strong predictor of cerebral blood flow.

• Grey matter/white matter ratio and cerebral blood flow barely declined until the age of 25 in all participants.

• There were further cerebral blood flow reductions in those older than 35 years of age.

• Cerebral blood flow was independent of disease state, hemoglobin S, hemoglobin F, reticulocyte count and cell free hemoglobin.

Citation: Bush A, Borzage M, Choi S, et al. Determinants of resting cerebral blood flow in sickle cell disease. [Published online ahead of print July 4, 2016]. Am J Hematol. doi:10.1002/ajh.24441.