@inbook{ad33ca60f033419c93ce569eece21911,
title = "Pulse amplitude of intracranial pressure waveform in hydrocephalus",
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.",
keywords = "Improvement, Intracranial pressure, Normal pressure hydrocephalus, Pulse waveform, Shunting",
author = "Z. Czosnyka and N. Keong and Kim, {D. J.} and D. Radolovich and P. Smielewski and A. Lavinio and Schmidt, {E. A.} and S. Momjian and B. Owler and Pickard, {J. D.} and M. Czosnyka",
year = "2008",
doi = "10.1007/978-3-211-85578-2_28",
language = "English",
isbn = "9783211855775",
series = "Acta Neurochirurgica, Supplementum",
publisher = "Springer-Verlag Wien",
number = "102",
pages = "137--140",
booktitle = "Intracranial Pressure and Brain Monitoring XIII",
edition = "102",
}