Intracranial pulsatility in patients with cerebral small vessel disease: a systematic review

Abstract

Growing evidence suggests that increased intracranial pulsatility is associated with cerebral small vessel disease (SVD). We systematically reviewed papers that assessed intracranial pulsatility in subjects with SVD. We included 27 cross-sectional studies (=3356): 20 used Doppler ultrasound and 7 used phase-contrast MRI. Most studies measured pulsatility in the internal carotid or middle cerebral arteries (ICA, MCA), whereas few assessed veins or cerebrospinal fluid (CSF). Methods to reduce bias and risk factor adjustment were poorly reported. Substantial variation between studies in assessment of SVD and of pulsatility indices precluded a formal meta-analysis. Eight studies compared pulsatility by SVD severity (=26-159, median = 74.5): arterial pulsatility index was generally higher in more severe SVD (e.g. MCA: standardized mean difference = 3.24, 95% confidence interval [2.40, 4.07]), although most did not match for age. Seventeen studies (=9-700; median = 110) performed regression or correlation analysis, of which most showed that increased pulsatility was associated with SVD after adjustment for age. In conclusion, most studies support a cross-sectional association between higher pulsatility in large intracranial arteries and SVD. Future studies should minimize bias, adjust for potential confounders, include pulsatility in veins and CSF, and examine longitudinal relationship between pulsatility and SVD. Agreement on reliable measures of intracranial pulsatility would be helpful.

White matter hyperintensities and the pulsatility index: fellow travelers or partners in crime?

“…They observed that the elevated pulsatility index obtained in the middle cerebral artery was significantly correlated with severe WMHs, using the Fazekas scale. They confirmed the growing evidence supporting the association between increased intracranial pulsatility and cerebral small vessel disease 24 .…”

Small vessel disease is associated with altered cerebrovascular pulsatility but not resting cerebral blood flow

“…[12][13][14] However, in these studies, pulsatility was assessed in one (or at most two) main cerebral arteries by ultrasound. 15 Very few studies assessed pulsatility in the arteries, veins and CSF contemporaneously in the same subjects, 16 limiting the clinical evidence.…”

“…21 However, so far, no clinical studies have measured cranial vascular pulsatility and PVS visibility. 15 Pulse-gated phase-contrast MRI is able to detect flow and pulsatility in major cerebral vessels and CSF spaces.…”

Intracranial functional haemodynamic relationships in patients with cerebral small vessel disease

“…aqueduct, foramen magnum) within one examination, concurrently with CVR, making it possible to assess relationships between CVR, CBF and pulsatility directly. However, there are very few studies of intracranial pulsatility assessed with MRI in ageing or SVD(19) and no studies in humans of CVR assessed concurrently with intracranial vascular pulsatility, CSF flow dynamics, or resting CBF, to provide a complete assessment of intracranial haemodynamics.…”