TY - JOUR
T1 - Assessing low-frequency oscillations in cerebrovascular diseases and related conditions with near-infrared spectroscopy
T2 - A plausible method for evaluating cerebral autoregulation?
AU - Andersen, Adam Vittrup
AU - Simonsen, Sofie Amalie
AU - Schytz, Henrik Winther
AU - Iversen, Helle Klingenberg
PY - 2018
Y1 - 2018
N2 - Cerebral autoregulation (CA) is the brain's ability to always maintain an adequate and relatively constant blood supply, which is often impaired in cerebrovascular diseases. Near-infrared spectroscopy (NIRS) examines oxygenated hemoglobin (OxyHb) in the cerebral cortex. Low- and very low-frequency oscillations (LFOs 0.1 Hz and VLFOs 0.05 to 0.01 Hz) in OxyHb have been proposed to reflect CA. Aim: To systematically review published results on OxyHb LFOs and VLFOs in cerebrovascular diseases and related conditions measured with NIRS. Approach: A systematic search was performed in the MEDLINE database, which generated 36 studies relevant for inclusion. Results: Healthy people have relatively stable LFOs. LFO amplitude seems to reflect myogenic CA being decreased by vasomotor paralysis in stroke, by smooth muscle damage or as compensatory action in other conditions but can also be influenced by the sympathetic tone. VLFO amplitude is believed to reflect neurogenic and metabolic CA and is lower in stroke, atherosclerosis, and with aging. Both LFO and VLFO synchronizations appear disturbed in stroke, while the former is also altered in internal carotid stenosis and hypertension. Conclusion: We conclude that amplitudes of LFOs and VLFOs are relatively robust measures for evaluating mechanisms of CA and synchronization analyses can show temporal disruption of CA. Further research and more coherent methodologies are needed.
AB - Cerebral autoregulation (CA) is the brain's ability to always maintain an adequate and relatively constant blood supply, which is often impaired in cerebrovascular diseases. Near-infrared spectroscopy (NIRS) examines oxygenated hemoglobin (OxyHb) in the cerebral cortex. Low- and very low-frequency oscillations (LFOs 0.1 Hz and VLFOs 0.05 to 0.01 Hz) in OxyHb have been proposed to reflect CA. Aim: To systematically review published results on OxyHb LFOs and VLFOs in cerebrovascular diseases and related conditions measured with NIRS. Approach: A systematic search was performed in the MEDLINE database, which generated 36 studies relevant for inclusion. Results: Healthy people have relatively stable LFOs. LFO amplitude seems to reflect myogenic CA being decreased by vasomotor paralysis in stroke, by smooth muscle damage or as compensatory action in other conditions but can also be influenced by the sympathetic tone. VLFO amplitude is believed to reflect neurogenic and metabolic CA and is lower in stroke, atherosclerosis, and with aging. Both LFO and VLFO synchronizations appear disturbed in stroke, while the former is also altered in internal carotid stenosis and hypertension. Conclusion: We conclude that amplitudes of LFOs and VLFOs are relatively robust measures for evaluating mechanisms of CA and synchronization analyses can show temporal disruption of CA. Further research and more coherent methodologies are needed.
KW - cerebral autoregulation
KW - cerebrovascular diseases
KW - low-frequency oscillations
KW - near-infrared spectroscopy
KW - risk of stroke.
U2 - 10.1117/1.NPh.5.3.030901
DO - 10.1117/1.NPh.5.3.030901
M3 - Review
C2 - 30689678
AN - SCOPUS:85054061899
SN - 2329-423X
VL - 5
JO - Neurophotonics
JF - Neurophotonics
IS - 3
M1 - 030901
ER -