Obstructive sleep apnea (OSA) subjects show brain injury in sites that control autonomic, cognitive, and mood functions that are deficient in the condition. The processes contributing to injury may include altered blood-brain barrier (BBB) actions. Our aim was to examine BBB function, based on diffusion-weighted pseudo-continuous arterial spin labeling (DW-pCASL) procedures, in OSA compared to controls.
We performed DW-pCASL imaging in 9 OSA and 9 controls on a 3.0-Tesla MRI scanner. Global mean gray and white matter arterial transient time (ATT, an index of large artery integrity), water exchange rate across the BBB (Kw, BBB function), DW-pCASL ratio, and cerebral blood flow (CBF) values were compared between OSA and control subjects.
Global mean gray and white matter ATT (OSA vs controls; gray matter, 1.691±0.120 vs 1.658±0.109 sec, p=0.49; white matter, 1.700±0.115 vs 1.650±0.114 sec, p=0.44), and CBF values (gray matter, 57.4±15.8 vs 58.2±10.7 ml/100g/min, p=0.67; white matter, 24.2±7.0 vs 24.6±6.7 ml/100g/min, p=0.91) did not differ significantly, but global gray and white matter Kw (gray matter, 158.0±28.9 vs 220.8±40.6 min −1, p=0.002; white matter, 177.5±57.2 vs 261.1±51.0 min −1, p=0.006), and DW-pCASL ratio (gray matter, 0.727±0.076 vs 0.823±0.069, p=0.011; white matter, 0.722±0.144 vs 0.888±0.100, p=0.004) values were significantly reduced in OSA over controls.