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Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure
A siphon is suggested to support cerebral blood flow but appears not to be established because internal jugular venous (IJV) pressure is close to zero in upright humans. Thus, in eleven young healthy males, IJV pressure was 9 ± 1 mmHg (mean ± SE) when supine and fell to 3 ± 1 mmHg when seated, and m...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2014
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4139713/ https://www.ncbi.nlm.nih.gov/pubmed/25191276 http://dx.doi.org/10.3389/fphys.2014.00317 |
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author | Olesen, Niels D. van Lieshout, Johannes J. Fisher, James P. Seifert, Thomas Nielsen, Henning B. Secher, Niels H. |
author_facet | Olesen, Niels D. van Lieshout, Johannes J. Fisher, James P. Seifert, Thomas Nielsen, Henning B. Secher, Niels H. |
author_sort | Olesen, Niels D. |
collection | PubMed |
description | A siphon is suggested to support cerebral blood flow but appears not to be established because internal jugular venous (IJV) pressure is close to zero in upright humans. Thus, in eleven young healthy males, IJV pressure was 9 ± 1 mmHg (mean ± SE) when supine and fell to 3 ± 1 mmHg when seated, and middle cerebral artery mean blood velocity (MCA V(mean); P < 0.007) and the near-infrared spectroscopy-determined frontal lobe oxygenation (S(c)O(2); P = 0.028) also decreased. Another subject, however, developed (pre)syncopal symptoms while seated and his IJV pressure decreased to −17 mmHg. Furthermore, his MCA V(mean) decreased and yet within the time of observation S(c)O(2) was not necessarily affected. These findings support the hypothesis that a negative IJV pressure that is a prerequisite for creation of a siphon provokes venous collapse inside the dura, and thereby limits rather than supports CBF. |
format | Online Article Text |
id | pubmed-4139713 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-41397132014-09-04 Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure Olesen, Niels D. van Lieshout, Johannes J. Fisher, James P. Seifert, Thomas Nielsen, Henning B. Secher, Niels H. Front Physiol Physiology A siphon is suggested to support cerebral blood flow but appears not to be established because internal jugular venous (IJV) pressure is close to zero in upright humans. Thus, in eleven young healthy males, IJV pressure was 9 ± 1 mmHg (mean ± SE) when supine and fell to 3 ± 1 mmHg when seated, and middle cerebral artery mean blood velocity (MCA V(mean); P < 0.007) and the near-infrared spectroscopy-determined frontal lobe oxygenation (S(c)O(2); P = 0.028) also decreased. Another subject, however, developed (pre)syncopal symptoms while seated and his IJV pressure decreased to −17 mmHg. Furthermore, his MCA V(mean) decreased and yet within the time of observation S(c)O(2) was not necessarily affected. These findings support the hypothesis that a negative IJV pressure that is a prerequisite for creation of a siphon provokes venous collapse inside the dura, and thereby limits rather than supports CBF. Frontiers Media S.A. 2014-08-21 /pmc/articles/PMC4139713/ /pubmed/25191276 http://dx.doi.org/10.3389/fphys.2014.00317 Text en Copyright © 2014 Olesen, van Lieshout, Fisher, Seifert, Nielsen and Secher. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Physiology Olesen, Niels D. van Lieshout, Johannes J. Fisher, James P. Seifert, Thomas Nielsen, Henning B. Secher, Niels H. Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure |
title | Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure |
title_full | Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure |
title_fullStr | Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure |
title_full_unstemmed | Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure |
title_short | Case report: (Pre)syncopal symptoms associated with a negative internal jugular venous pressure |
title_sort | case report: (pre)syncopal symptoms associated with a negative internal jugular venous pressure |
topic | Physiology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4139713/ https://www.ncbi.nlm.nih.gov/pubmed/25191276 http://dx.doi.org/10.3389/fphys.2014.00317 |
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