Intracranial Pressure Changes Derived from Near Infrared Spectroscopy Measurements in Non-Human Primates

2018 ◽  
Author(s):  
Alexander Ruesch ◽  
Samantha Schmitt ◽  
Jason Yang ◽  
Matthew A. Smith ◽  
Jana M. Kainerstorfer
Keyword(s):  
Infrared Spectroscopy ◽  
Intracranial Pressure ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Pressure Changes

scholarly journals Increased cerebral blood volume pulsatility during head-down tilt with elevated carbon dioxide: the SPACECOT Study

2017 ◽  
Vol 123 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Gary E. Strangman ◽  
Quan Zhang ◽  
Karina Marshall-Goebel ◽  
Edwin Mulder ◽  
Brian Stevens ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Intracranial Pressure ◽  
Blood Volume ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Blood Volume ◽  
Optic Disk ◽  
Fluid Shifts ◽  
Mayer Wave ◽  
Over Time

Astronauts aboard the International Space Station (ISS) have exhibited hyperopic shifts, posterior eye globe flattening, dilated optic nerve sheaths, and even optic disk swelling from spaceflight. Elevated intracranial pressure (ICP) consequent to cephalad fluid shifts is commonly hypothesized as contributing to these ocular changes. Head-down tilt (HDT) is frequently utilized as an Earth-based analog to study similar fluid shifts. Sealed environments like the ISS also exhibit elevated CO2, a potent arteriolar vasodilator that could further affect cerebral blood volume (CBV) and cerebral blood flow, intracranial compliance, and ICP. A collaborative pilot study between the National Space Biomedical Research Institute and the German Aerospace Center tested the hypotheses that 1) HDT and elevated CO2 physiologically interact and 2) cerebrovascular pulsatility is related to HDT and/or elevated CO2. In a double-blind crossover study ( n = 6), we measured CBV pulsatility via near-infrared spectroscopy, alongside noninvasive ICP and intraocular pressure (IOP) during 28-h −12° HDT at both nominal (0.04%) and elevated (0.5%) ambient CO2. In our cohort, CBV pulsatility increased significantly over time at cardiac frequencies (0.031 ± 0.009 μM/h increase in total hemoglobin concentration pulsatility amplitude) and Mayer wave frequencies (0.019 ± 0.005 μM/h increase). The HDT-CO2 interaction on pulsatility was not robust but rather driven by one individual. Significant differences between atmospheres were not detected in ICP or IOP. Further work is needed to determine whether individual differences in pulsatility responses to CO2 relate to visual changes in space. NEW & NOTEWORTHY Cerebral blood volume (CBV) pulsatility—as measured by near-infrared spectroscopy—increases over time during −12° head-down tilt at both cardiac and Mayer wave frequencies. CBV pulsatility appeared to increase more under elevated (0.5%) CO2 at Mayer wave frequencies in some individuals. If similar dynamic pulsatility increases occur in astronauts, there is the potential to initiate vascular and possibly other remodeling processes that lead to symptoms associated with sustained increases in intracranial pressure.

Cytochrome aa3 and Intracranial Pressure in Newborn Infants; A Near Infrared Spectroscopy Study*

1992 ◽  
Vol 23 (02) ◽  
pp. 111-111 ◽  
Author(s):  
P. Casaer ◽  
K. Siebenthal ◽  
A. van der Vlugt ◽  
L. Lagae ◽  
H. Devlieger
Keyword(s):  
Infrared Spectroscopy ◽  
Intracranial Pressure ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Newborn Infants ◽  
Spectroscopy Study ◽  
Cytochrome Aa3

scholarly journals EFFECT OF CHANGES IN INTRACRANIAL PRESSURE ON CYTOCHROME AA3 (CYTAA3) AND HAEMOGLOBINVOLUME (HBVOL): A NEAR INFRARED SPECTROSCOPY (NIRS)

1992 ◽  
Vol 32 (5) ◽  
pp. 612-612 ◽  
Author(s):  
Study Kurt Von Siebenthai ◽  
Amerins Van Der Vlugt ◽  
Hugo Devlieger ◽  
Paul Casaer
Keyword(s):  
Infrared Spectroscopy ◽  
Intracranial Pressure ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cytochrome Aa3

scholarly journals Fluctuations in intracranial pressure can be estimated non-invasively using near-infrared spectroscopy in non-human primates

2019 ◽  
Vol 40 (11) ◽  
pp. 2304-2314 ◽  
Author(s):  
Alexander Ruesch ◽  
Samantha Schmitt ◽  
Jason Yang ◽  
Matthew A Smith ◽  
Jana M Kainerstorfer
Keyword(s):  
Infrared Spectroscopy ◽  
Intracranial Pressure ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Optical Data ◽  
Macaque Model ◽  
Non Invasive ◽  
Time Alignment ◽  
Highly Correlated ◽  
Changes Over Time

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.

Assessment of Cerebral Autoregulation Patterns with Near-infrared Spectroscopy during Pharmacological-induced Pressure Changes

2015 ◽  
Vol 123 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Annelies T. Moerman ◽  
Valerie M. Vanbiervliet ◽  
Astrid Van Wesemael ◽  
Stefaan M. Bouchez ◽  
Patrick F. Wouters ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Cerebral Autoregulation ◽  
Near Infrared ◽  
Pressure Effects ◽  
Cerebral Oximetry ◽  
Spearman Correlation ◽  
Elective Cardiac Surgery ◽  
Pressure Changes

Abstract Background: Previous work has demonstrated paradoxical increases in cerebral oxygen saturation (ScO2) as blood pressure decreases and paradoxical decreases in ScO2 as blood pressure increases. It has been suggested that these paradoxical responses indicate a functional cerebral autoregulation mechanism. Accordingly, the authors hypothesized that if this suggestion is correct, paradoxical responses will occur exclusively in patients with intact cerebral autoregulation. Methods: Thirty-four patients undergoing elective cardiac surgery were included. Cerebral autoregulation was assessed with the near-infrared spectroscopy–derived cerebral oximetry index (COx), computed by calculating the Spearman correlation coefficient between mean arterial pressure and ScO2. COx less than 0.30 was previously defined as functional autoregulation. During cardiopulmonary bypass, 20% change in blood pressure was accomplished with the use of nitroprusside for decreasing pressure and phenylephrine for increasing pressure. Effects on COx were assessed. Data were analyzed using two-way ANOVA, Kruskal–Wallis test, and Wilcoxon and Mann–Whitney U test. Results: Sixty-five percent of patients had a baseline COx less than 0.30, indicating functional baseline autoregulation. In 50% of these patients (n = 10), COx became highly negative after vasoactive drug administration (from −0.04 [−0.25 to 0.16] to −0.63 [−0.83 to −0.26] after administration of phenylephrine, and from −0.05 [−0.19 to 0.17] to −0.55 [−0.94 to −0.35] after administration of nitroprusside). A negative COx implies a decrease in ScO2 with increase in pressure and, conversely, an increase in ScO2 with decrease in pressure. Conclusions: In this study, paradoxical changes in ScO2 after pharmacological-induced pressure changes occurred exclusively in patients with intact cerebral autoregulation, corroborating the hypothesis that these paradoxical responses might be attributable to a functional cerebral autoregulation.

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