Pulse amplitude of intracranial pressure waveform in hydrocephalus

Z. Czosnyka, N. Keong, D. J. Kim, D. Radolovich, P. Smielewski, A. Lavinio, E. A. Schmidt, S. Momjian, B. Owler, J. D. Pickard, M. Czosnyka

Research output: Chapter in Book/Report/Conference proceedingChapter

9 Citations (Scopus)

Abstract

Background There is increasing interest in evaluation of the pulse amplitude of intracranial pressure (AMP) in explaining dynamic aspects of hydrocephalus. We reviewed a large number of ICP recordings in a group of hydrocephalic patients to assess utility of AMP. Materials and methods From a database including approximately 2,100 cases of infusion studies (either lumbar or intraventricular) and overnight ICP monitoring in patients suffering from hydrocephalus of various types (both communicating and non-communicating), etiology and stage of management (non-shunted or shunted) pressure recordings were evaluated. For subgroup analysis we selected 60 patients with idiopathic NPH with full follow-up after shunting. In 29 patients we compared pulse amplitude during an infusion study performed before and after shunting with a properly functioning shunt. Amplitude was calculated from ICP waveforms using spectral analysis methodology. Findings A large amplitude was associated with good outcome after shunting (positive predictive value of clinical improvement for AMP above 2.5 mmHg was 95%). However, low amplitude did not predict poor outcome (for AMP below 2.5 mmHg 52% of patients improved). Correlations of AMP with ICP and Rcsf were positive and statistically significant (N=131 with idiopathic NPH; R= 0.21 for correlation with mean ICP and 0.22 with Rcsf; p< 0.01). Correlation with the brain elastance coefficient (or PVI) was not significant. There was also no significant correlation between pulse amplitude and width of the ventricles. The pulse amplitude decreased (p<0.005) after shunting. Conclusions Interpretation of the ICP pulse waveform may be clinically useful in patients suffering from hydrocephalus. Elevated amplitude seems to be a positive predictor for clinical improvement after shunting. A properly functioning shunt reduces the pulse amplitude.

Original languageEnglish
Title of host publicationIntracranial Pressure and Brain Monitoring XIII
Subtitle of host publicationMechanisms and Treatment
PublisherSpringer-Verlag Wien
Pages137-140
Number of pages4
Edition102
ISBN (Print)9783211855775
DOIs
Publication statusPublished - 2008

Publication series

NameActa Neurochirurgica, Supplementum
Number102
ISSN (Print)0065-1419

Keywords

  • Improvement
  • Intracranial pressure
  • Normal pressure hydrocephalus
  • Pulse waveform
  • Shunting

ASJC Scopus subject areas

  • Surgery
  • Clinical Neurology

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  • Cite this

    Czosnyka, Z., Keong, N., Kim, D. J., Radolovich, D., Smielewski, P., Lavinio, A., Schmidt, E. A., Momjian, S., Owler, B., Pickard, J. D., & Czosnyka, M. (2008). Pulse amplitude of intracranial pressure waveform in hydrocephalus. In Intracranial Pressure and Brain Monitoring XIII: Mechanisms and Treatment (102 ed., pp. 137-140). (Acta Neurochirurgica, Supplementum; No. 102). Springer-Verlag Wien. https://doi.org/10.1007/978-3-211-85578-2_28