Diffuse optical assessment of cerebral-autoregulation in older adults stratified by cerebrovascular risk

Ahmed A. Bahrani, Weikai Kong, Yu Shang, Chong Huang, Charles D. Smith, David K. Powell, Yang Jiang, Abner O. Rayapati, Gregory A. Jicha, Guoqiang Yu

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Diagnosis of cerebrovascular disease (CVD) at early stages is essential for preventing sequential complications. CVD is often associated with abnormal cerebral microvasculature, which may impact cerebral-autoregulation (CA). A novel hybrid near-infrared diffuse optical instrument and a finger plethysmograph were used to simultaneously detect low-frequency oscillations (LFOs) of cerebral blood flow (CBF), oxy-hemoglobin concentration ([HbO2]), deoxy-hemoglobin concentration ([Hb]) and mean arterial pressure (MAP) in older adults before, during and after 70° head-up-tilting (HUT). The participants with valid data were divided based on Framingham risk score (FRS, 1-30 points) into low-risk (FRS ≤15, n = 13) and high-risk (FRS '15, n = 11) groups for developing CVD. The LFO gains were determined by transfer function analyses with MAP as the input, and CBF, [HbO2] and [Hb] as the outputs (CA ∝ 1/Gain). At resting-baseline, LFO gains in the high-risk group were relatively lower compared to the low-risk group. The lower baseline gains in the high-risk group may attribute to compensatory mechanisms to maintain stronger steady-state CAs. However, HUT resulted in smaller gain reductions in the high-risk group compared to the low-risk group, suggesting weaker dynamic CAs. LFO gains are potentially valuable biomarkers for early detection of CVD based on associations with CAs.

Original languageEnglish
Article numbere202000073
JournalJournal of Biophotonics
Issue number10
StatePublished - Oct 1 2020

Bibliographical note

Funding Information:
We acknowledge the support from The Higher Committee for Education Development in Iraq, and the advice from Dr Fred Schmitt at the University of Kentucky Alzheimer's Disease Center (ADC) and Dr. Erin Abner at the Department of Epidemiology and Department of Biostatistics, University of Kentucky. This work was partially supported by the National Institutes of Health (NIH, 5P30‐AG028383, R21‐HD091118, R01‐HD101508 and R01‐AG062480), American Heart Association (AHA, 16GIA‐30820006) and National Science Foundation (NSF, EPSCoR‐1539068). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH, AHA, or NSF.

Funding Information:
American Heart Association, Grant/Award Number: 16GIA30820006; Higher Committee for Education Development in Iraq, Grant/Award Number: Supporting the primary author scholarship; National Institutes of Health, Grant/Award Numbers: 1R01AG062480, 5P30AG028383, R01‐HD101508, R21‐HD091118; National Science Foundation (NSF), Grant/Award Number: EPSCoR1539068 Funding information 2

Publisher Copyright:
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • cerebral blood flow
  • cerebral blood oxygenation
  • cerebral-autoregulation
  • cerebrovascular disease
  • diffuse correlation spectroscopy
  • head-up-tilting
  • low-frequency oscillation
  • near-infrared spectroscopy

ASJC Scopus subject areas

  • Chemistry (all)
  • Materials Science (all)
  • Biochemistry, Genetics and Molecular Biology (all)
  • Engineering (all)
  • Physics and Astronomy (all)


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