In vivo vascular hallmarks of diffuse leukoaraiosis

Abstract

Purpose To characterize multiple patterns of vascular changes in leukoaraiosis using in vivo magnetic resonance imaging (MRI) techniques. Materials and Methods We measured cerebral blood flow (CBF), cerebrovascular reactivity (CVR), and blood–brain-barrier (BBB) leakage in a group of 33 elderly subjects (age: 72.3 ± 6.8 years, 17 males, 16 females). Leukoaraiosis brain regions were identified in each subject using fluid-attenuated inversion-recovery (FLAIR) MRI. Vascular parameters in the leukoaraiosis regions were compared to those in the normal-appearing white matter (NAWM) regions. Vascular changes in leukoaraiosis were also compared to structural damage as assessed by diffusion tensor imaging. Results CBF and CVR in leukoaraiosis regions were found to be 39.7 ± 5.2% (P < 0.001) and 52.5 ± 11.6% (P = 0.005), respectively, of those in NAWM. In subjects who did not have significant leukoaraiosis, CBF and CVR in regions with high risk for leukoaraiosis showed a slight reduction compared to the other white matter regions. Significant BBB leakage was also detected (P = 0.003) in leukoaraiosis and the extent of BBB leakage was positively correlated with mean diffusivity. In addition, CVR in NAWM was lower than that in white matter of subjects without significant leukoaraiosis. Conclusion Leukoaraiosis was characterized by reduced CBF, CVR, and a leakage in the BBB.

Vascular Dysfunction in Leukoaraiosis

“…These results are similar to findings from a previous study by Uh et al 22 reporting lower CVR values in leukoaraiosis. However, the approach to CVR quantification in the present study is more accurate.…”

“…Our results are consistent with those in other studies reporting CBF reductions in leukoaraiosis compared with NAWM, 22,[45][46][47] but they are not in agreement for CBV. We found a reduction in CBV, possibly due to a loss of vascular density, whereas another study showed no difference in CBV between leukoaraiosis and NAWM.…”

“…40 Quantitative T2 values were higher in leukoaraiosis, which is to be expected because this indicates increased water content due to loss in tissue structure. 41 CBF was reduced; this change indicated a reduction in blood supply, 22 CBV was also reduced; this change suggested decreased density of the local microvasculature. 42 Finally, timedependent MR imaging metrics such as time-to-maximum and TTP were prolonged in leukoaraiosis; this finding demonstrates a delay in the blood supply to areas of leukoaraiosis.…”

“…Moreover, vascular dysfunction in the form of blood-brain barrier leakage in WMH is also associated with increased MD. 22 We evaluated CVR in regions of WMH and normal-appearing white matter (NAWM) by measuring the change in blood oxygen level-dependent (BOLD) MR imaging in response to a standard CO 2 challenge. To characterize the hemodynamic properties and microstructure of WMH, we obtained additional MR images and performed DTI and DSC perfusion MR imaging.…”

Leukoaraiosis Predicts Poor 90-Day Outcome after Acute Large Cerebral Artery Occlusion

“…Originally noted as diffuse, non-specific subcortical white matter lesions on CT, leukoaraiosis (LA) is a common finding among patients with ischemic stroke and has been associated with poor post-stroke outcomes as well as increased risk for recombinant tissue plasminogen activator (rtPA)-associated intracranial hemorrhage [4,5,6,7]. LA has been associated with reduced brain perfusion and cerebrovascular reactivity and may therefore considerably decrease penumbral survival and negatively affect outcome [8,9]. Yet, contribution of LA to outcome in stroke patients with ILAO remains to be clarified.…”