Frequency-resolved analysis of coherent oscillations of local cerebral blood volume, measured with near-infrared spectroscopy, and systemic arterial pressure in healthy human subjects

PLoS One. 2019 Feb 12;14(2):e0211710. doi: 10.1371/journal.pone.0211710. eCollection 2019.

Abstract

We report a study on twenty-two healthy human subjects of the dynamic relationship between cerebral hemoglobin concentration ([HbT]), measured with near-infrared spectroscopy (NIRS) in the prefrontal cortex, and systemic arterial blood pressure (ABP), measured with finger plethysmography. [HbT] is a measure of local cerebral blood volume (CBV). We induced hemodynamic oscillations at discrete frequencies in the range 0.04-0.20 Hz with cyclic inflation and deflation of pneumatic cuffs wrapped around the subject's thighs. We modeled the transfer function of ABP and [HbT] in terms of effective arterial (K(a)) and venous (K(v)) compliances, and a cerebral autoregulation time constant (τ(AR)). The mean values (± standard errors) of these parameters across the twenty-two subjects were K(a) = 0.01 ± 0.01 μM/mmHg, K(v) = 0.09 ± 0.05 μM/mmHg, and τ(AR) = 2.2 ± 1.3 s. Spatially resolved measurements in a subset of eight subjects reveal a spatial variability of these parameters that may exceed the inter-subject variability at a set location. This study sheds some light onto the role that ABP and cerebral blood flow (CBF) play in the dynamics of [HbT] measured with NIRS, and paves the way for new non-invasive optical studies of cerebral blood flow and cerebral autoregulation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Arterial Pressure* / physiology
  • Cerebral Blood Volume* / physiology
  • Cerebrum / blood supply
  • Cerebrum / chemistry
  • Cerebrum / physiology
  • Female
  • Hemodynamics
  • Hemoglobins / analysis
  • Humans
  • Male
  • Middle Aged
  • Plethysmography
  • Spectroscopy, Near-Infrared
  • Young Adult

Substances

  • Hemoglobins