Fluctuations in intracranial pressure can be estimated non-invasively using near-infrared spectroscopy in non-human primates. Issue 11 (November 2020)

• Record Type: Journal Article
• Authors: Ruesch, Alexander; Schmitt, Samantha; Yang, Jason; Smith, Matthew A; Kainerstorfer, Jana M
• Is Part Of: Journal of cerebral blood flow & metabolism. Volume 40:Issue 11(2020)
• Page Start: 2304
• Page End: 2314
• Publication Date: 2020-11
• Subjects: Intracranial pressure -- near-infrared spectroscopy -- non-human primates -- transfer function -- hemodynamics; Cerebral circulation -- Periodicals; Brain -- Metabolism -- Periodicals; Brain -- Blood-vessels -- Periodicals; Cerebrovascular disease -- Periodicals; 612.824
• DOI: 10.1177/0271678X19891359
• Languages: English
• ISSNs: 0271-678X

Abstract

Intracranial pressure (ICP) is typically measured invasively through a sensor placed inside the brain or a needle inserted into the spinal canal, limiting the patient population on which this assessment can be performed. Currently, non-invasive methods are limited due to lack of sensitivity and thus only apply to extreme cases of increased ICP, instead of use in general clinical practice. We demonstrate a novel application for near-infrared spectroscopy (NIRS) to accurately estimate ICP changes over time. Using a non-human primate (Rhesus Macaque) model, we collected optical data while we induced ICP oscillations at multiple ICP levels obtained by manipulating the height of a fluid column connected via a catheter to the lateral ventricle. Hemodynamic responses to ICP changes were measured at the occipital pole and compared to changes detected by a conventional intraparenchymal ICP probe. We demonstrate that hemoglobin concentrations are highly correlated with induced ICP oscillations and that this response is frequency dependent. We translated the NIRS data into non-invasive ICP measurements via a fitted non-parametric transfer function, demonstrating a match in both magnitude and time alignment with an invasively measured reference. Our results demonstrate that NIRS has the potential for non-invasive ICP monitoring.