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Brain-Related Assessments for Investigating the Neurophysiology of SANS (BRAIN-SANS) (80NSSC20K0841)
Research Area:
Behavior and performance
Human factors
Species Studied
Scientific Name: Homo sapiens Species: Human


Spaceflight associated neuro-ocular syndrome (SANS) remains an important and unmitigated risk to long duration spaceflight. Out of 68 astronauts, about 10 have shown SANS with ocular findings such as acquired hyperopia, globe flattening and choroidal folds. While the cause of SANS remains unknown, the observed ocular symptoms coupled with the slightly elevated (or normal) intra-ocular pressure shows that intracranial pressure may be elevated compared to average Earth levels. These symptoms point towards possible involvement of cephalad fluid shifts being the cause. A major challenge for understanding SANS has been availability of suitable, non-invasive assessments beyond the ocular and ophthalmological measures used for diagnosis. Current hypotheses suggest that the lack of gravity leads to fluid shifting towards the head, resulting in congestion and/or elevated pressures in the cranial, vascular and/or lymphatic compartments. This study proposed to provide numerous key measures to meet NASA’s proposal to conduct 30-day head-down tilt (HDT) experiments to test SANS countermeasures (CM) at the :envihab facility in Germany. This study proposed key measurements in support of these planned 30-day missions. Focus will be placed on developing a toolkit for detailed neurophysiological and fluid shift assessment and monitoring suitable for measuring SANS and countermeasure related changes. These tools will be designed to complement the standard ocular measures used for SANS diagnosis and monitoring.

This study proposes to address the following aims:
  1. 1. Develop an integrated hardware and software toolbox to support multiple simultaneous, continuous brain monitoring and imaging capabilities.
  2. 2. Test SANS hypotheses and also characterize and quantify individual subjects’ physiological responses to HDT and each planned SANS CMs.
  3. 3. Relate neurophysiological changes over the 30- day HDT, with and without CMs to cognitive and operational performance, ocular measures, sleep, and mood.

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Blood pressure
Blood volume

Data Information
Data Availability
Archiving in progress. Data is not yet available for this experiment.

Blood pressure
blood volume shifts
Cerebral Edema assessment
Cerebral electrical activity
Cerebral pulsatility assessment
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Ground 05/01/2009 In Progress

Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Institutional Support
National Aeronautics and Space Administration (NASA)
Proposal Date
Proposal Source
2018-2019 HERO 80JSC018N0001-SANS: Spaceflight Associated Neuro-ocular Syndrome Countermeasures. Appendix C