Non-invasive assessment of intracranial pressure for space flight and related visual impairment (IPVI) - 05.17.18

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ISS Science for Everyone

Science Objectives for Everyone
Long-duration spaceflight increases pressure in the head, resulting in changes to the shape of crew members’ eyes and optic nerves and causing vision changes. The Intracranial Pressure and Visual Impairment (IPVI) investigation studies these changes by analyzing arterial blood pressure and blood flow in the brain before and after spaceflight.
Science Results for Everyone
Information Pending

The following content was provided by Hiroshi Ohshima, M.D., Ph.D., and is maintained in a database by the ISS Program Science Office.
Information provided courtesy of the Japan Aerospace and Exploration Agency (JAXA).
Experiment Details

OpNom: Intracranial Pressure & Visual Impairment

Principal Investigator(s)
Kenichi Iwasaki, M.D., Ph.D., Nihon University School of Medicine, Tokyo, Japan

Yojiro Ogawa, D.D.S., Ph.D., Nihon University School of Medicine, Tokyo, Japan
Ari Shinojima, M.D., Ph.D., Nihon University School of Medicine, Tokyo, Japan
Ryo Yanagida, M.D., Ph.D., Nihon University School of Medicine, Tokyo, Japan
Thomas Heldt, Ph.D., Computational Physiology & Clinical Inference Group, Cambridge, MA, United States
Benjamin D. Levine, M.D., University of Texas Southwestern Medical Center, Dallas, TX, United States

Tsukuba Space Center, Tsukuba, Ibaraki, Japan

Sponsoring Space Agency
Japan Aerospace Exploration Agency (JAXA)

Sponsoring Organization
Japan Aerospace Exploration Agency

Research Benefits
Earth Benefits, Scientific Discovery, Space Exploration

ISS Expedition Duration
March 2015 - March 2016; March 2016 - August 2018

Expeditions Assigned

Previous Missions
Neurolab Mission (STS-90)

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Experiment Description

Research Overview

Very recently, medical doctors found that some crew members on the International Space Station (ISS) seem to be at risk for impairments of the eye (e.g. optic disc edema). This may be due to elevations in intracranial pressure induced by long-duration spaceflight. So, this experiment investigates “intracranial pressure“ on crew members, by using multiple indexes that can be obtained non-invasively.
Non-invasively, this investigation estimates the changes in intracranial pressure and brain circulation before, and after long-duration spaceflights, by analyzing the “arterial blood pressure waveform” and the “brain blood flow waveform.” In addition, the investigation team hopes to confirm that abnormalities of the eye occur among the crew members whose intracranial pressure has increased.
The major impact of this research seeks to advance the understanding of human pathophysiology during spaceflight. Moreover, it is hoped that this investigation method leads to a screening examination for elevated intracranial pressure on crew members. The non-invasive method may be appropriate for the monitoring of space-related intracranial alterations, and can be used for preventing visual impairments (e.g. optic disc edema).

Information Pending

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Space Applications
Recent studies have shown some crew members on the ISS experience swelling of the optic nerve, which can affect their vision. This may be because of elevated intracranial pressure, or pressure inside the head, which happens in microgravity. The investigation aims to confirm that eye abnormalities, such as swelling of the optic nerve, happen in crew members whose cranial pressure has increased. The investigation’s non-invasive measurement methods could be used for early detection of this pressure change.

Earth Applications
Physicians currently use invasive procedures to measure intracranial pressure, including inserting a needle in a person’s spine. The IPVI investigation uses a non-invasive method instead, gauging intracranial pressure by combining arterial blood pressure and brain blood flow. Results from this investigation can benefit patients on Earth who need to be tested for high intracranial pressure, or who need other measurements for ailments such as fluid on the brain, brain swelling, or low intracranial pressure.

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Operational Requirements and Protocols

Number of subjects:  10 astronauts
In flight
There is no constraint during flight.
Downlink of crew image of in-flight facial edema check by the principal investigator (PI) on the ground.
Pre and Post-BDC
Constraints for subjects are shown below:
a.  Crews whose ABP and CBFV wave form can be measured (check at screening or #1pre-BDC).
b.  No maximal exercise including VO2 Max, and NBL within 12 hours before each BDC session.
c.  More than 6 hours should elapsed after nitroglycerin, and more than 1 hour should be elapsed after catecholamines, etc.
d.  No caffeine, nicotine, or alcohol for 12 hours prior to testing.
e.  No heavy meals within last 4 hours. Light snack of complex carbohydrates are OK within 2 hours of testing.
f.  Other medicine and exercise logs of subjects for 6 hours prior to testing are required if acceptable.
Data sharing
The following data sharing are requested:
Ophthalmology/Optometry (MEDB 1.10), (MR014L)
If acceptable Laboratory Testing (MEDB2.1)
On-Orbit Strength & Conditioning Monitoring (MEDB 5.2), Medication history at pre-/in-/post-flight
In flight
Principal investigator (PI) on the ground checks facial edema for crew in-flight around L+4(+1/-1) month.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites

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