Cerebrovascular Regulation and Sleep Apnea
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Purpose of Review
The brain relies on a constant blood flow to match nutrient delivery with the local metabolic demands. Cerebral blood flow (CBF) autoregulation is particularly important under hypoxic conditions such as obstructive sleep apnea (OSA) to prevent brain hypoxia. We aim to give a brief overview of cerebral blood flow regulation and evaluate the current evidence for cerebrovascular sensitivity to hypoxia, the capacity of cerebral arteries to respond to reduced oxygen supply during normal sleep and OSA.
In clinical conditions such as intermittent hypoxia as well as untreated OSA, cerebrovascular system becomes less reactive to CO2 and impaired autoregulation, and makes the brain more susceptible to ischemic stroke.
Results from studies in patients with OSA indicate worse clinical outcome including higher chance of cerebrovascular events, impaired functional capacity and cognition. Early treatment of OSA with continuous positive airway pressure (CPAP), resulting in reversal of cerebral autoregulation.
KeywordsObstructive sleep apnea Sleep disordered breathing Cerebral blood flow Stroke Cerebral autoregulation
Compliance with Ethical Standards
Conflict of Interest
Behrouz Jafari declares no conflicts of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
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- 9.Cheyne JA. A case of apoplexy in which the fleshy part of the heart was converted into fat. Dublin Hosp Rep. 1818;2:216–22.Google Scholar
- 11.Somers VK, White DP, Amin R, Abraham WT, Costa F, Culebras A, et al. Sleep apnea and cardiovascular disease: an American Heart Association/American College Of Cardiology Foundation scientific statement from the American Heart Association Council for high blood pressure research professional education committee, council on clinical cardiology, stroke council, and council on cardiovascular nursing. In collaboration with the National Heart, Lung, and Blood Institute National Center on sleep disorders research (National Institutes of Health). Circulation. 2008;118(10):1080–111.CrossRefPubMedGoogle Scholar
- 27.Henriksen L, Paulson OB. The effects of sodium nitroprusside on cerebral blood flow and cerebral venous blood gases in man. Acta Medica Scand Suppl. 1983;678:91–6.Google Scholar
- 30.Van de Borne P, Nguyen H, Biston P, Linkowski P, Degaute JP. Effects of wake and sleep stages on the 24-h autonomic control of blood pressure and heart rate in recumbent men. Am J Phys. 1994;266(2 Pt 2):H548–54.Google Scholar
- 35.Burgess HJ, Trinder J, Kim Y, Luke D. Sleep and circadian influences on cardiac autonomic nervous system activity. Am J Phys. 1997;273(4 Pt 2):H1761–8.Google Scholar
- 46.•• Jackman KA, Zhou P, Faraco G, Peixoto PM, Coleman C, Voss HU, et al. Dichotomous effects of chronic intermittent hypoxia on focal cerebral ischemic injury. Stroke. 2014;45(5):1460–7. This study suggest chronic mild intermittent hypoxia can elicit ischemic preconditionioning and have neuroprotective effect. CrossRefPubMedPubMedCentralGoogle Scholar
- 53.•• Waltz X, Beaudin AE, Hanly PJ, Mitsis GD, Poulin MJ. Effects of continuous positive airway pressure and isocapnic-hypoxia on cerebral autoregulation in patients with obstructive sleep apnoea. J Physiol. 2016;594(23):7089–104. This study suggest that sympathetic overactivity may be responsible for cerebral dysregulation in more severe forms of OSA. CrossRefPubMedPubMedCentralGoogle Scholar
- 58.• Hayen A, Herigstad M, Kelly M, Okell TW, Murphy K, Wise RG, et al. The effects of altered intrathoracic pressure on resting cerebral blood flow and its response to visual stimulation. NeuroImage. 2013;66:479–88. This study suggest altered intrathoracic pressures, whether induced experimentally, therapeutically or through a disease process, have possible significant effects on CBF. CrossRefPubMedPubMedCentralGoogle Scholar
- 64.• Vigetun-Haughey H, Appelberg J, Forsberg T, Kaldensjo M, Schagatay E. Voluntary apnea evokes diving responses in obstructive sleep apnea patients. Eur J Appl Physiol. 2015;115(5):1029–36. This study represent an important mechanism to match temporal brain oxygen demand. Sympathetic overactivity also causes spleen contraction, results in autotransfusion of red blood cells and improve oxygen transport to the vital organs. CrossRefPubMedGoogle Scholar
- 85.Martinez-Garcia MA, Soler-Cataluna JJ, Ejarque-Martinez L, Soriano Y, Roman-Sanchez P, Illa FB, et al. Continuous positive airway pressure treatment reduces mortality in patients with ischemic stroke and obstructive sleep apnea: a 5-year follow-up study. Am J Respir Crit Care Med. 2009;180(1):36–41.CrossRefPubMedGoogle Scholar