• Neurological research · Jan 1998

    Resolving extra- and intracranial signal changes during adult near infrared spectroscopy.

    • P J Kirkpatrick, P Smielewski, P Al-Rawi, and M Czosnyka.
    • University Department of Neurosurgery, Addenbrookes Hospital, Cambridge, UK.
    • Neurol. Res. 1998 Jan 1; 20 Suppl 1: S19-22.

    AbstractExtracranial tissues have a significant effect on cerebral near infrared spectroscopy (NIRS) measurements in adults. Carotid surgery provides the opportunity to determine the relative contributions from the intra- and extracranial vascular territories. To assist, a specifically gated Laser Doppler flowmetry probe can be inserted between the NIRS optodes to co-monitor cutaneous blood flow associated with external carotid artery (ECA) clamping, whilst transcranial Doppler can be employed to monitor relative changes in the intracranial blood flow seen during internal carotid artery (ICA) clamping. Established criteria for severe cerebral ischemia (SCI) following carotid cross clamping was applied to 703 consecutive patients undergoing carotid surgery for high grade stenosis. Ipsilateral frontal NIRS recorded the difference (Total-deltaHbdiff) in concentrations of oxy- and deoxy-hemoglobin. Interrupted time series analysis following clamping of the ECA and ICA allowed the different vascular components of Total-deltaHbdiff (ECA-deltaHbdiff and ICA-deltaHbdiff) to be identified. Data from 76 patients was suitable. Sixteen (21%) patients fulfilled the criteria for SCI. Patients who demonstrated an ICA-deltaHbdiff of > 6.8 micromol l(-1) all showed SCI. No patient with an ICA-deltaHbdiff < 5.0 micromol l(-1) showed SCI. Thus an ICA-deltaHbdiff threshold of 6.8 micromol l(-1) provided a 100% specificity for SCI, whereas an ICA-deltaHbdiff < 5.0 micromol l(-1) was 100% sensitive for excluding SCI. When Total-deltaHbdiff was used without removing the ECA component, thresholds for SCI could not be resolved. NIRS can provide quantified thresholds for severe ischemia in the adult brain provided the extracranial component is removed.

      Pubmed     Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…

What will the 'Medical Journal of You' look like?

Start your free 21 day trial now.

We guarantee your privacy. Your email address will not be shared.