Edinburgh Imaging

05 May 20. Featured Paper

Intracranial hemodynamic relationships in patients with cerebral small vessel disease.

Link to paper on American Academy of Neurology

 

Authors

Gordon W. BlairMichael J. Thrippleton, Yulu Shi, Iona HamiltonMichael StringerFrancesca ChappellDavid Alexander DickiePeter AndrewsIan MarshallFergus N. DoubalJoanna M. Wardlaw

 

Abstract

Objective: To investigate cerebrovascular reactivity (CVR), blood flow, vascular & CSF pulsatility, & their independent relationship with cerebral small vessel disease (SVD) features in patients with minor ischemic stroke & MRI evidence of SVD.

Methods: We recruited patients with minor ischemic stroke & assessed CVR using blood oxygen level–dependent MRI during a hypercapnic challenge, cerebral blood flow (CBF), vascular & CSF pulsatility using phase-contrast MRI, & structural magnetic resonance brain imaging to quantify white matter hyperintensities (WMHs) & perivascular spaces (PVSs).

We used multiple regression to identify parameters associated with SVD features, controlling for patient characteristics.

Results: Fifty-three of 60 patients completed the study with a full data set (age 68.0% ± 8.8 years, 74% male, 75% hypertensive).

After controlling for age, sex, & systolic blood pressure, lower white matter CVR was associated with higher WMH volume (−0.01%/mm Hg per log10 increase in WMH volume, p = 0.02), basal ganglia PVS (−0.01%/mm Hg per point increase in the PVS score, p = 0.02), & higher venous pulsatility (superior sagittal sinus −0.03%/mm Hg, p = 0.02, per unit increase in the pulsatility index) but not with CBF (p = 0.58).

Lower foramen magnum CSF stroke volume was associated with worse white matter CVR (0.04%/mm Hg per mL increase in stroke volume, p = 0.04) & more severe basal ganglia PVS (p = 0.09).

Conclusions: Lower CVR, higher venous pulsatility, & lower foramen magnum CSF stroke volume indicate that dynamic vascular dysfunctions underpin PVS dysfunction & WMH development.

Further exploration of microvascular dysfunction & CSF dynamics may uncover new mechanisms & intervention targets to reduce SVD lesion development, cognitive decline, & stroke.

 

Keywords