Near infrared spectroscopy as possible non-invasive monitor of slow vasogenic ICP waves

Ruwan Alwis Weerakkody, Marek Czosnyka*, Christian Zweifel, Gianluca Castellani, Peter Smielewski, Kenneth Martin Brady, John D. Pickard, Zofia Czosnyka

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

30 Scopus citations


We aimed to study synchronisation between ICP and near infrared spectroscopy (NIRS) variables induced by vasogenic waves of ICP during an infusion study in hydrocephalic patients and after TBI. Nineteen patients presenting with hydrocephalus underwent a diagnostic intraventricular constant-flow infusion test. The original concept of the methodology, presented in the current paper, was derived from this material. Then the method was applied in 40 TBI patients, with results reported in an observational manner. During monitoring, NIRS deoxygenated and oxygenated haemoglobin (Hb, HbO 2) were recorded simultaneously with ICP. Moving correlation coefficient (6 min) between Hb and HbO2 was tested as a marker of the slow vasogenic waves of ICP. During infusion studies ICP increased from 10.7 (5.1) mmHg to a plateau of 18.9 (7.6) mmHg, which was associated with an increase in the power of slow ICP waves (p = 0.000017). Fluctuations of Hb and HbO2 at baseline negatively correlated with each other, but switched to high positive values during periods of increased ICP slow-wave activity during infusion (p < 0.001). Similar behaviour was observed in TBI patients: baseline negative Hb/HbO2 correlation changed to positive values during peaks of ICP of vasogenic nature. Correlating changes in Hb and HbO 2 may be of use as a method of non-invasive detection of vasogenic ICP waves.

Original languageEnglish (US)
Title of host publicationIntracranial Pressure and Brain Monitoring XIV
PublisherSpringer-Verlag Wien
Number of pages5
ISBN (Print)9783709109557
StatePublished - 2012

Publication series

NameActa Neurochirurgica, Supplementum
ISSN (Print)0065-1419
ISSN (Electronic)0001-6268


  • Infusion test
  • Intracranial pressure
  • Near infrared spectroscopy
  • Traumatic brain injury

ASJC Scopus subject areas

  • Surgery
  • Clinical Neurology


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