Pulsatile microvascular cerebral blood flow waveforms change with intracranial compliance and age

Diffuse correlation spectroscopy (DCS) is an optical method to mea- sure relative changes in cerebral blood flow (rCBF) in the microvasculature. Each heartbeat generates a pulsatile signal with distinct morphological features that we hypothesized to be related to intracranial compliance (ICC).

We aim to study how three features of the pulsatile rCBF waveforms: the augmentation index (AIx), the pulsatility index, and the area under the curve, change with respect to ICC. We describe ICC as a combination of vascular compliance and extravascular compliance.

Our results suggest that the AIx measured in the cerebral micro-vasculature using DCS may be correlated to changes in ICC.