Non-Invasively Estimated ICP Pulse Amplitude Strongly Correlates with Outcome After TBI

  • Karol P. BudohoskiEmail author
  • Bernhard Schmidt
  • Peter Smielewski
  • Magdalena Kasprowicz
  • Ronny Plontke
  • John D. Pickard
  • Jurgen Klingelhöfer
  • Marek Czosnyka
Part of the Acta Neurochirurgica Supplementum book series (NEUROCHIRURGICA, volume 114)


Introduction: An existing monitoring database of brain signal recordings in patients with head injury has been re-evaluated with regard to the accuracy of estimation of non-invasive ICP (nICP) and its components, with a particular interest in the implications for outcome after head injury.

Methods: Middle cerebral artery blood flow velocity (FV), ICP and arterial blood pressure (ABP) were recorded. Non-invasive ICP (nICP) was calculated using a mathematical model. Other signals analysed included components of ICP (n” indicates non-invasive): ICP pulse amplitude (Amp, nAmp), amplitude of the respiratory component (Resp, nResp), amplitude of slow vasogenic waves of ICP (Slow, nSlow) and index of compensatory reserve (RAP, nRAP). Mean values of analysed signals were compared against each other and between patients who died and survived.

Results: The correlation between ICP and nICP was moderately strong, R = 0.51 (95% prediction interval [PI] 17 mm Hg). The components of nICP and ICP were also moderately correlated with each other: the strongest correlation was observed for Resp vs. nResp (r = 0.66), while weaker for Amp vs. nAmp (r = 0.41). Non-invasive pulse amplitude of ICP showed the strongest association with outcome, with the ­difference between those who survived and those who died reaching a significance level of p < 0.000001.

Discussion: When compared between patients who died and who survived mean nAmp showed the greatest difference, suggesting its potential to predict mortality after TBI.


Intracranial pressure Non-invasive ICP Pulse amplitude of intracranial pressure Slow waves of intracranial pressure Traumatic brain injury Outcome 


Conflict of interest

KPB was sponsored by the Graduate Travel and Research Fund of St. Catharine’s College, University of Cambridge, UK and the Clifford and Mary Corbridge Trust. ICM+  software is licensed by the University of Cambridge, Cambridge Enterprise Ltd. PS and MC have a financial interest in a part of its licensing fee. Non-invasive ICP Plugin is protected by patent DE 19600983. BS and MC have a financial interest in part of its licensing fee.


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Copyright information

© Springer-Verlag/Wien 2012

Authors and Affiliations

  • Karol P. Budohoski
    • 1
    Email author
  • Bernhard Schmidt
    • 2
  • Peter Smielewski
    • 1
  • Magdalena Kasprowicz
    • 1
    • 3
  • Ronny Plontke
    • 2
  • John D. Pickard
    • 1
  • Jurgen Klingelhöfer
    • 2
  • Marek Czosnyka
    • 1
  1. 1.Department of Clinical Neurosciences, Division of NeurosurgeryAddenbrooke’s HospitalCambridgeUK
  2. 2.Department of NeurologyUniversity Hospital ChemnitzChemnitzGermany
  3. 3.Institute of Biomedical Engineering and InstrumentationWroclaw University of TechnologyWroclawPoland

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