title: Analysis of slow wave oscillations in cerebral haemodynamics and metabolism following subarachnoid haemorrhage.
abstract: Aneurysmal subarachnoid haemorrhage (SAH) causes the greatest loss of productive life years of any form of stroke. Emerging concepts of pathophysiology highlight early abnormalities of microvascular function, including impaired autoregulation of cerebral blood flow and flow-metabolism coupling, as key causes of cerebral ischaemia and poor outcome. Near infrared spectroscopy (NIRS) is a non-invasive optical technique which may help identify cerebral microvascular dysfunction. The aim of this research is to investigate the status of flow-metabolism coupling by examining phase relationships between NIRS-derived concentrations of oxy-haemoglobin ([HbO₂]), deoxy-haemoglobin ([HHb]) and cytochrome c oxidase oxidation ([oxCCO]). Eight sedated ventilated patients with SAH were investigated. A combined NIRS broadband and frequency domain spectroscopy system was used to measure [HbO₂], [HHb] and [oxCCO] alongside other multimodal neuromonitoring. Wavelet analysis of phase relationships revealed antiphase [HbO₂]-[oxCCO] and in-phase [HbO₂]-[HHb] oscillations between 0.1Hz-0.01Hz consistent with compromised flow-metabolism coupling. NIRS derived variables might offer unique insights into microvascular and metabolic dysfunction following SAH, and in the future identify therapeutic windows or targets.
authors.affiliation: Neurocritical Care, University College Hospitals, Queen Square, London, UK. d.highton@ucl.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Highton
authors.affiliation: Neurocritical Care, University College Hospitals, Queen Square, London, UK.
authors.forename: Arnab
authors.initials: A
authors.lastname: Ghosh
authors.affiliation: Medical Physics & Bioengineering, University College London, Malet Place, London, UK.
authors.forename: Ilias
authors.initials: I
authors.lastname: Tachtsidis
authors.affiliation: Medical Physics & Bioengineering, University College London, Malet Place, London, UK.
authors.forename: Clare
authors.initials: C
authors.lastname: Elwell
authors.affiliation: Neurocritical Care, University College Hospitals, Queen Square, London, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Smith
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000503:physiopathology*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000503:physiopathology*; D055815:Young Adult
references.citation: Biomed Opt Express. 2012 Oct 1;3(10):2550-66
references.pmid: 23082295
references.citation: J Neurosurg. 2008 Sep;109(3):424-32
references.pmid: 18759572
references.citation: Neurocrit Care. 2010 Jun;12(3):313-6
references.pmid: 20390380
references.citation: Neuroimage. 2014 Jan 15;85 Pt 1:234-44
references.pmid: 23707584
references.citation: Adv Exp Med Biol. 2011;701:233-9
references.pmid: 21445792
references.citation: Mol Neurobiol. 2011 Feb;43(1):27-40
references.pmid: 21161614
references.citation: Lancet Neurol. 2009 Apr;8(4):355-69
references.pmid: 19233729
references.citation: Neuroimage. 2000 Dec;12(6):623-39
references.pmid: 11112395
references.citation: Neuroimage. 2013 Aug 1;76:70-80
references.pmid: 23507389
references.citation: Stroke. 2012 Dec;43(12):3230-7
references.pmid: 23150652
references.citation: Adv Exp Med Biol. 2012;737:307-13
references.pmid: 22259118