This Article Full Text Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schmidt, B. Articles by Wittich, I. Search for Related Content PubMed PubMed Citation Articles by Schmidt, B. Articles by Wittich, I.

(Stroke. 1997;28:2465-2472.)
© 1997 American Heart Association, Inc.

Articles

Noninvasive Prediction of Intracranial Pressure Curves Using Transcranial Doppler Ultrasonography and Blood Pressure Curves

Bernhard Schmidt, PhD; Jürgen Klingelhöfer, MD; Jens Jürgen Schwarze, MD; Dirk Sander, MD; Ingo Wittich, MD

From the Department of Neurology, Technical University of Munich (Germany).

Background and Purpose Until now the assessment of intracranial pressure (ICP) required invasive methods. The objective of this study was to introduce an approach to a noninvasive assessment of continuous ICP curves.

Methods The intracranial compartment was considered a "black box" system with an input signal, the arterial blood pressure (ABP), and an output signal, the ICP. A so-called weight function described the relationship between ABP and ICP curves. Certain parameters, called transcranial Doppler (TCD) characteristics, were calculated from the cerebral blood flow velocity (FV) and the ABP curves and were used to estimate this weight function. From simultaneously sampled FV, ABP, and (invasively measured) ICP curves of a defined group of patients with severe head injuries, the TCD characteristics and the weight function were computed. Multiple regression analysis revealed a mathematical formula for calculating the weight function from TCD characteristics. This formula was used to generate the ICP simulation. FV, ABP, and ICP recordings from 11 patients (mean age, 46±14 years) with severe head injury were studied. In each patient, ICP was computed by a simulation procedure, generated from the data of the remaining 10 patients. The simulation period was 100 seconds.

Results Corresponding pressure trends with a mean absolute difference of 4.0±1.8 mm Hg between computed and measured ICP were observed. Shapes of pulse and respiratory ICP modulations were clearly predicted.

Conclusions These results demonstrate that this method constitutes a promising step toward a noninvasive ICP prediction that may be clinically applicable under well-defined conditions.

Key Words: blood flow velocity • blood pressure • head injury • intracranial pressure • ultrasonics

This article has been cited by other articles:

				J. Marti-Fabregas, R. Belvis, E. Guardia, D. Cocho, and J.-L. Marti-Vilalta Relationship between Transcranial Doppler and CT Data in Acute Intracerebral Hemorrhage AJNR Am. J. Neuroradiol., January 1, 2005; 26(1): 113 - 118. [Abstract] [Full Text] [PDF]

				M Czosnyka and J D Pickard Monitoring and interpretation of intracranial pressure J. Neurol. Neurosurg. Psychiatry, June 1, 2004; 75(6): 813 - 821. [Abstract] [Full Text] [PDF]

				J. Marti-Fabregas, R. Belvis, E. Guardia, D. Cocho, J. Munoz, L. Marruecos, and J.-L. Marti-Vilalta Prognostic value of Pulsatility Index in acute intracerebral hemorrhage Neurology, October 28, 2003; 61(8): 1051 - 1056. [Abstract] [Full Text] [PDF]

				B. Schmidt, M. Czosnyka, A. Raabe, H. Yahya, J. J. Schwarze, D. Sackerer, D. Sander, and J. Klingelhofer Adaptive Noninvasive Assessment of Intracranial Pressure and Cerebral Autoregulation Stroke, January 1, 2003; 34(1): 84 - 89. [Abstract] [Full Text] [PDF]

				S. A. Mayer and J. Y. Chong Critical Care Management of Increased Intracranial Pressure J Intensive Care Med, March 1, 2002; 17(2): 55 - 67. [Abstract] [PDF]

				N. J. Alperin, S. H. Lee, F. Loth, P. B. Raksin, and T. Lichtor MR-Intracranial Pressure (ICP): A Method to Measure Intracranial Elastance and Pressure Noninvasively by Means of MR Imaging: Baboon and Human Study Radiology, December 1, 2000; 217(3): 877 - 885. [Abstract] [Full Text]