Subpeak regional analysis of intracranial pressure waveform morphology based on cerebrospinal fluid hydrodynamics in the cerebral aqueduct and prepontine cistern

The objective of this study is to investigate the relationship between intracranial pressure (ICP) pulse waveform morphology and selected hydrodynamic metrics of cerebrospinal fluid (CSF) movement using a novel method for ICP pulse pressure regional analysis based on the Morphological Clustering and Analysis of Continuous Intracranial Pulse (MOCAIP) algorithm. Methods: Seven patients received both overnight ICP monitoring along with a phase contrast MRI (PC-MRI) of the cerebral aqueduct and prepontine cistern to measure peak velocity, peak to peak mean flow, and stroke volume. Waveform morphological analysis of the ICP signal was performed by the MOCAIP algorithm. Following extraction of morphological metrics from the ICP signal, each ICP metric (128 metrics) was compared to each CSF metric via Spearman´s rank correlation. The ICP results were further analyzed using a binary scheme which assigned the individual metrics a regional contribution based on the characteristic triphasic ICP pulse waveform. Results: All three aqueductal CSF metrics were shown to be significantly correlated with region 2 of the triphasic ICP pulse pressure waveform. Furthermore, the prepontine cistern showed two significant correlations between the CSF metrics and region 3 of the ICP waveform. Conclusion: In this study we showed that non-invasive measures of CSF movement in two different anatomical locations are significantly related to different sub-peak regions of the ICP pulse pressure waveform.