J Neuroeng Rehabil. 2006 Jul 19;3:16. doi: 10.1186/1743-0003-3-16.
Relationship between oxygen supply and cerebral blood flow assessed by transcranial Doppler and near-infrared spectroscopy in healthy subjects during breath-holding.
Journal of neuroengineering and rehabilitation
Filippo Molinari, William Liboni, Gianfranco Grippi, Emanuela Negri
PMID: 16854224
PMCID: PMC1544341 DOI: 10.1186/1743-0003-3-16
Abstract
BACKGROUND: Breath-holding (BH) is a suitable method for inducing cerebral vasomotor reactivity (VMR). The assessment of VMR is of clinical importance for the early detection of risk conditions and for the follow-up of disabled patients. Transcranial Doppler ultrasonography (TCD) is used to measure cerebral blood flow velocity (CBFV) during BH, whereas near-infrared spectroscopy (NIRS) measures the concentrations of the oxygenated (O2Hb) and reduced (CO2Hb) hemoglobin. The two techniques provide circulatory and functional-related parameters. The aim of the study is the analysis of the relationship between oxygen supply and CBFV as detected by TCD and NIRS in healthy subjects performing BH.
METHODS: 20 healthy subjects (15 males and 5 females, age 33 +/- 4.5 years) underwent TCD and NIRS examination during voluntary breath-holding. VMR was quantified by means of the breath-holding index (BHI). We evaluated the BHI based on mean CBFV, O(2)Hb and CO(2)Hb concentrations, relating the baseline to post-stimulus values. To quantify VMR we also computed the slope of the linear regression line of the concentration signals during BH. From the NIRS signals we also derived the bidimensional representation of VMR, plotting the instantaneous O(2)Hb concentration vs the CO(2)Hb concentration during the BH phase. Two subjects, a 30 years old current smoker female and a 63 years old male with a ischemic stroke event at the left middle cerebral artery, were tested as case studies.
RESULTS: The BHI for the CBFV was equal to 1.28 +/- 0.71 %/s, the BHI for the O(2)Hb to 0.055 +/- 0.037 micromol/l/s and the BHI for CO2Hb to 0.0006 +/- 0.0019 micromol/l/s, the O2Hb slope was equal to 0.15 +/- 0.09 micromol/l/s and the CO(2)Hb slope to 0.09 +/- 0.04 micromol/l/s. There was a positive correlation between the CBFV and the O(2)Hb increments during BH (r = 0.865). The bidimensional VMR pattern shows common features among healthy subjects that are lost in the control studies.
CONCLUSION: We show that healthy subjects present a common VMR pattern when counteracting cerebral blood flow perturbations induced by voluntary BH. The proposed methodology allows for the monitoring of changes in the VMR pattern, hence it could be used for assessing the efficacy of neurorehabilitation protocols.
References
- Stroke. 2000 Apr;31(4):924-9 - PubMed
- J Neurol Sci. 2002 Dec 15;205(1):71-5 - PubMed
- J Neurol Sci. 2002 Dec 15;205(1):15-20 - PubMed
- Headache. 2004 Jan;44(1):29-34 - PubMed
- Stroke. 1990 Sep;21(9):1306-11 - PubMed
- Arch Gerontol Geriatr. 2004 Nov-Dec;39(3):207-25 - PubMed
- Appl Opt. 1997 Jan 1;36(1):21-31 - PubMed
- JAMA. 1983 Nov 25;250(20):2796-800 - PubMed
- J Auton Pharmacol. 1999 Apr;19(2):105-8 - PubMed
- Stroke. 1983 Sep-Oct;14(5):720-4 - PubMed
- J Neurol Neurosurg Psychiatry. 2002 Jul;73(1):34-9 - PubMed
- Funct Neurol. 1990 Jan-Mar;5(1):33-41 - PubMed
- J Physiol Anthropol Appl Human Sci. 2004 Jul;23(4):105-10 - PubMed
- Neuroimage. 1998 Jul;8(1):69-78 - PubMed
- Biophys J. 1993 Mar;64(3):803-12 - PubMed
- Stroke. 1995 Dec;26(12):2285-92 - PubMed
- Br J Anaesth. 2003 Jun;90(6):774-86 - PubMed
- Stroke. 2002 Aug;33(8):2032-6 - PubMed
- Stroke. 2004 Jan;35(1):64-70 - PubMed
- Yakubutsu Seishin Kodo. 1993 Jun;13(3):183-90 - PubMed
Publication Types