{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T12:29:28Z","timestamp":1789129768913,"version":"build-2803163510"},"reference-count":32,"publisher":"Public Library of Science (PLoS)","issue":"6","license":[{"start":{"date-parts":[[2023,6,22]],"date-time":"2023-06-22T00:00:00Z","timestamp":1687392000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100008131","name":"Rheinische Friedrich-Wilhelms-Universit\u00e4t Bonn","doi-asserted-by":"publisher","award":["2018-FKS-04"],"award-info":[{"award-number":["2018-FKS-04"]}],"id":[{"id":"10.13039\/501100008131","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\">\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>Recently, cerebral autoregulation indices based on moving correlation indices between mean arterial pressure (MAP) and cerebral oximetry (NIRS, ORx) or transcranial Doppler (TCD)-derived middle cerebral artery flow velocity (Mx) have been introduced to clinical practice. In a pilot study, we aimed to evaluate the validity of these indices using incremental lower body negative pressure (LBNP) until presyncope representing beginning cerebral hypoperfusion as well as lower body positive pressure (LBPP) with added mild hypoxia to induce cerebral hyperperfusion in healthy subjects.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec002\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Five male subjects received continuous hemodynamic, TCD and NIRS monitoring. Decreasing levels of LBNP were applied in 5-minute steps until subjects reached presyncope. Increasing levels of LBPP were applied stepwise up to 20 or 25 mmHg. Normobaric hypoxia was added until an oxygen saturation of 84% was reached. This was continued for 10 minutes. ORx and Mx indices were calculated using previously described methods.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec003\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Both Indices showed an increase &gt; 0.3 indicating impaired cerebral autoregulation during presyncope. However, there was no significant difference in Mx at presyncope compared to baseline (p = 0.168). Mean arterial pressure and cardiac output decreased only in presyncope, while stroke volume was decreased at the last pressure level. Neither Mx nor ORx showed significant changes during LBPP or hypoxia. Agreement between Mx and ORx was poor during the LBNP and LBPP experiments (R\n                      <jats:sup>2<\/jats:sup>\n                      = 0.001, p = 0.3339).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec004\">\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Mx and ORx represent impaired cerebral autoregulation, but in Mx this may not be distinguished sufficiently from baseline. LBPP and hypoxia are insufficient to reach the upper limit of cerebral autoregulation as indicated by Mx and ORx.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1371\/journal.pone.0287578","type":"journal-article","created":{"date-parts":[[2023,6,23]],"date-time":"2023-06-23T05:35:48Z","timestamp":1687498548000},"page":"e0287578","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":5,"title":["Cerebral blood flow autoregulation assessment by correlation analysis between mean arterial blood pressure and transcranial doppler sonography or near infrared spectroscopy is different: A pilot 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Blood Flow and Oxygen Consumption in Man","volume":"39","author":"NA Lassen","year":"1959","journal-title":"Physiol Rev"},{"key":"pone.0287578.ref002","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1093\/qjmed\/hcm009","article-title":"Cerebral hyperperfusion syndrome following carotid endarterectomy","volume":"100","author":"V Adhiyaman","year":"2007","journal-title":"QJM"},{"key":"pone.0287578.ref003","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1213\/ANE.0b013e31823d292a","article-title":"Predicting the limits of cerebral autoregulation during cardiopulmonary bypass","volume":"114","author":"B Joshi","year":"2012","journal-title":"Anesth Analg"},{"key":"pone.0287578.ref004","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1213\/ANE.0b013e3181c6fd12","article-title":"Impaired Autoregulation of Cerebral Blood Flow During Rewarming from Hypothermic Cardiopulmonary Bypass and Its Potential Association with Stroke","volume":"110","author":"B Joshi","year":"2010","journal-title":"Anesth Analg"},{"key":"pone.0287578.ref005","doi-asserted-by":"crossref","first-page":"R181","DOI":"10.1186\/cc11665","article-title":"Impaired cerebrovascular autoregulation in patients with severe sepsis and sepsis-associated delirium","volume":"16","author":"P Schramm","year":"2012","journal-title":"Crit Care"},{"key":"pone.0287578.ref006","doi-asserted-by":"crossref","first-page":"1951","DOI":"10.1161\/STROKEAHA.109.575159","article-title":"Real-time continuous monitoring of cerebral blood flow autoregulation using near-infrared spectroscopy in patients undergoing cardiopulmonary bypass","volume":"41","author":"K Brady","year":"2010","journal-title":"Stroke"},{"key":"pone.0287578.ref007","doi-asserted-by":"crossref","first-page":"719","DOI":"10.1093\/bja\/48.8.719","article-title":"PHYSIOLOGY OF CEREBRAL BLOOD FLOW","volume":"48","author":"NA Lassen","year":"1976","journal-title":"Br J Anaesth"},{"key":"pone.0287578.ref008","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1007\/s00421-013-2667-y","article-title":"Blood pressure regulation IX: cerebral autoregulation under blood pressure challenges","volume":"114","author":"Y-C Tzeng","year":"2014","journal-title":"Eur J Appl Physiol"},{"key":"pone.0287578.ref009","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1038\/sj.jcbfm.9600384","article-title":"Acute Exposure to Normobaric Mild Hypoxia Alters Dynamic Relationships between Blood Pressure and Cerebral Blood Flow at Very Low Frequency","volume":"27","author":"K Iwasaki","year":"2007","journal-title":"J Cereb Blood Flow Metab"},{"key":"pone.0287578.ref010","doi-asserted-by":"crossref","first-page":"1133","DOI":"10.1213\/01.ANE.0000111101.41190.99","article-title":"Continuous Assessment of Cerebral Autoregulation in Subarachnoid Hemorrhage","author":"M Soehle","year":"2004","journal-title":"Anesth 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Flow Response to Anesthesia, Pneumoperitoneum, and Head-up Tilt during Laparoscopic Cholecystectomy","volume":"131","author":"M Skytioti","year":"2019","journal-title":"Anesthesiology"},{"key":"pone.0287578.ref020","doi-asserted-by":"crossref","first-page":"e12969","DOI":"10.14814\/phy2.12969","article-title":"Internal carotid artery blood flow in healthy awake subjects is reduced by simulated hypovolemia and noninvasive mechanical ventilation","volume":"4","author":"M Skytioti","year":"2016","journal-title":"Physiol Rep"},{"key":"pone.0287578.ref021","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1111\/anae.12477","article-title":"Time course of cerebrovascular autoregulation during extreme Trendelenburg position for robotic-assisted prostatic surgery","volume":"69","author":"P Schramm","year":"2014","journal-title":"Anaesthesia"},{"key":"pone.0287578.ref022","doi-asserted-by":"crossref","first-page":"1324","DOI":"10.1111\/j.1399-6576.2009.02062.x","article-title":"Relationship between stroke volume, cardiac output and filling of the heart during tilt","volume":"53","author":"M Bundgaard-Nielsen","year":"2009","journal-title":"Acta Anaesthesiol Scand"},{"key":"pone.0287578.ref023","article-title":"Middle cerebral artery blood flow velocity in response to lower body positive pressure","author":"BG Perry","year":"2013","journal-title":"Clin Physiol Funct Imaging"},{"key":"pone.0287578.ref024","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1152\/japplphysiol.00778.2007","article-title":"Differential effects of acute hypoxia and high altitude on cerebral blood flow velocity and dynamic cerebral autoregulation: alterations with hyperoxia","volume":"104","author":"PN Ainslie","year":"2008","journal-title":"J Appl Physiol"},{"key":"pone.0287578.ref025","doi-asserted-by":"crossref","first-page":"H976","DOI":"10.1152\/ajpheart.00639.2006","article-title":"Alterations in cerebral autoregulation and cerebral blood flow velocity during acute hypoxia: rest and exercise","volume":"292","author":"PN Ainslie","year":"2007","journal-title":"Am J Physiol-Heart Circ Physiol"},{"key":"pone.0287578.ref026","doi-asserted-by":"crossref","first-page":"1165","DOI":"10.1152\/japplphysiol.00498.2009","article-title":"Acute hypoxia impairs dynamic cerebral autoregulation: results from two independent techniques","volume":"107","author":"AW Subudhi","year":"2009","journal-title":"J Appl Physiol"},{"key":"pone.0287578.ref027","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1113\/expphysiol.2008.045575","article-title":"Regulation of cerebral blood flow in mammals during chronic hypoxia: a matter of balance","volume":"95","author":"N. Ainslie Philip","year":"2010","journal-title":"Exp Physiol"},{"key":"pone.0287578.ref028","doi-asserted-by":"crossref","first-page":"2019","DOI":"10.1038\/jcbfm.2011.81","article-title":"Cerebral Artery Dilatation Maintains Cerebral Oxygenation at Extreme Altitude and in Acute Hypoxia\u2014An Ultrasound and MRI Study","volume":"31","author":"MH Wilson","year":"2011","journal-title":"J Cereb Blood Flow Metab"},{"key":"pone.0287578.ref029","first-page":"196","article-title":"Regulation of Cerebral Autoregulation by Carbon Dioxide","volume":"122","author":"L Meng","year":"2015","journal-title":"Anesthesiol J Am Soc Anesthesiol"},{"key":"pone.0287578.ref030","doi-asserted-by":"crossref","first-page":"H1461","DOI":"10.1152\/ajpheart.00948.2004","article-title":"Dynamic cerebral autoregulation during exhaustive exercise in humans","volume":"288","author":"S Ogoh","year":"2005","journal-title":"Am J Physiol\u2014Heart Circ Physiol"},{"key":"pone.0287578.ref031","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1152\/jappl.1998.85.1.160","article-title":"Effects of posture on cardiovascular responses to lower body positive pressure at rest and during dynamic exercise","volume":"85","author":"T Nishiyasu","year":"1998","journal-title":"J Appl Physiol"},{"key":"pone.0287578.ref032","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1007\/s12028-008-9140-5","article-title":"Near-Infrared Spectroscopy can Monitor Dynamic Cerebral Autoregulation in Adults","volume":"10","author":"LA Steiner","year":"2009","journal-title":"Neurocrit Care"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0287578","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,6,23]],"date-time":"2023-06-23T05:36:08Z","timestamp":1687498568000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0287578"}},"subtitle":[],"editor":[{"given":"Stephan","family":"Meckel","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2023,6,22]]},"references-count":32,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2023,6,22]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0287578","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,6,22]]}}}