Working...
ClinicalTrials.gov
ClinicalTrials.gov Menu

Cerebral Blood Flow Distribution During Parabolic Flight-induced Microgravity (GraCer)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT03986788
Recruitment Status : Enrolling by invitation
First Posted : June 14, 2019
Last Update Posted : June 14, 2019
Sponsor:
Collaborators:
Centre National d'Etudes Spatiales
Université de Caen Normandie
The University of New South Wales
Information provided by (Responsible Party):
University Hospital, Caen

Brief Summary:

When astronauts return from space flight, they manifest a set of symptoms, the most striking of which is orthostatic intolerance, that is, the inability to stay upright. This orthostatic intolerance is related to cardiovascular adaptation and disappears in a few days, but the prospect of long-term space travel makes this maladaptation a major concern of space agencies, at a time when there is serious consideration to make " land "a ship on Mars.

Previous studies suggest that brain vessel adaptation may contribute to spatial post-flight orthostatic intolerance. The question remains controversial because not all studies are consistent. These studies are all based on the measurement of blood flow in a single artery of the brain (the average cerebral, see cerebral circulation diagram) easily accessible with a Doppler ultrasound machine. Our team has good reason to believe that the adaptation of the cerebral vessels is not carried out in the same way in all the arteries of the brain and that in particular the arteries that irrigate the posterior and inferior parts of the brain are a major determinant. from cerebrovascular adaptation to orthostatism and that orthostatic intolerance is more specifically related to a decrease in blood flow in these arteries. On the other hand our team has shown that the external carotid artery plays, under certain conditions, a buffer role of the sudden variations of perfusion pressure of the brain.

During the weightless phase of parabolic flight, part of the blood from the legs and abdomen "rises" to the thorax and this transfer of fluid induces changes in blood pressure and cardiac output that affect the cerebral circulation. From a cardiovascular point of view, it is the same thing for a seated subject to lie down, but the parabolic flight offers the unique possibility of achieving this transfer in a fraction of a second and thus allowing to study the immediate response of the cerebral circulation. .

Investigators goal is therefore to quantify the changes in blood flow in the posterior and anterior territories of the brain (transcranial ultrasound) as well as in the internal carotid and vertebral (Doppler ultrasound) during changes in blood pressure and cardiac output induced by transfers. liquid resources associated with the transition to weightlessness.

The oxidative stress generated by weightlessness has been identified as a determining factor in cerebrovascular deconditioning associated with orthostatic intolerance. In order to quantify the biochemical markers of this stress, a venous sample will be taken before and just after the parabolic flight.


Condition or disease Intervention/treatment Phase
Weightlessness Cerebral Blood Flow Other: Weightlessness Not Applicable

  Show Detailed Description

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 18 participants
Intervention Model: Single Group Assignment
Intervention Model Description: Comparison of cerebral blood flow in 1G, 1.8 G and 0G conditions
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Effet de l'Impesanteur Sur la Distribution du débit Sanguin cérébral.
Actual Study Start Date : October 1, 2018
Estimated Primary Completion Date : September 30, 2021
Estimated Study Completion Date : September 30, 2021

Arm Intervention/treatment
Weightlessness
Weightlessness measurements during flight
Other: Weightlessness
Volunteers will be studied during parabolic flight. Cerebral blood flow will be measured in different part of the brain during weightlessness ans compared to 1g and hypergravity measurements.




Primary Outcome Measures :
  1. Cervical blood flow [ Time Frame: baseline ]
    Measurement of the cervical blood flow in external, internal and vertebral arteries.

  2. Transcranial blood flow [ Time Frame: baseline ]
    Measurement of the transcranial blood flow in anterior, middle and posterior cerebral arteries.



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Layout table for eligibility information
Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Healthy volunteers (men or women)
  • Aged from 18 to 65
  • Affiliated to a Social Security system and, for non-French resident, holding a European Health Insurance Card (EHIC)
  • Who accepted to take part in the study
  • Who have given their written stated consent
  • Who have passed a medical examination similar to a standard aviation medical examination for private pilot aptitude (JAR FCL3 Class 2 medical examination). There will be no additional test performed for subject selection.

Exclusion Criteria:

  • Persons who took part in a previous biomedical research protocol, of which exclusion period is not terminated.
  • Persons with history of cerebral, cardiovascular or vestibular diseases.
  • Pregnant women (urine pregnancy test for women of childbearing potential)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03986788


Locations
Layout table for location information
France
Novespace A310-0G
Mérignac, France, 33700
Sponsors and Collaborators
University Hospital, Caen
Centre National d'Etudes Spatiales
Université de Caen Normandie
The University of New South Wales
Investigators
Layout table for investigator information
Study Director: Christophe Kassel, Hospital Manager University Hospital, Caen

Additional Information:
Layout table for additonal information
Responsible Party: University Hospital, Caen
ClinicalTrials.gov Identifier: NCT03986788     History of Changes
Other Study ID Numbers: 2018-A01090-55
First Posted: June 14, 2019    Key Record Dates
Last Update Posted: June 14, 2019
Last Verified: May 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No