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Comparative Study
. 2021 Oct 1;4(10):e2131465.
doi: 10.1001/jamanetworkopen.2021.31465.

Comparison of Dural Venous Sinus Volumes Before and After Flight in Astronauts With and Without Spaceflight-Associated Neuro-Ocular Syndrome

Mark J Rosenberg  1 , Michael A Coker  2 , James A Taylor  2 , Milad Yazdani  2 , M Gisele Matheus  2 , Christopher K Blouin  2 , Sami Al Kasab  1   3 , Heather R Collins  2 , Donna R Roberts  2
Affiliations
Comparative Study

Comparison of Dural Venous Sinus Volumes Before and After Flight in Astronauts With and Without Spaceflight-Associated Neuro-Ocular Syndrome

Mark J Rosenberg et al. JAMA Netw Open. .

Abstract

Importance: Spaceflight-associated neuro-ocular syndrome (SANS) occurs in 40% to 60% of National Aeronautics and Space Administration (NASA) International Space Station (ISS) astronauts who present postflight with ophthalmological findings and elevated intracranial pressure. The etiology of SANS is unknown; it is hypothesized that venous outflow congestion from the head and neck occurs because of microgravity, which is supported by the finding of internal jugular vein stagnant flow and thrombosis in some astronauts, but the impact on intracranial dural venous sinus structures remains unknown.

Objectives: To clarify the potential risk of retrograde extension of clot intracranially among astronauts with internal jugular venous thrombosis by evaluating intracranial venous structures following spaceflight and to assess for any association between intracranial venous congestion and SANS.

Design, setting, and participants: This retrospective cohort study of all NASA astronauts who had undergone magnetic resonance (MR) venography at the time of the study included quantitative and qualitative assessments of the intracranial venous system on preflight and postflight MR venograms. Data were collected a mean (SD) of 525.8 (187.5) days before spaceflight and 2.0 (1.5) days after return to Earth. A semiautomated segmentation of the venogram images was used, which was then compared with a neuroradiologist's assessment.

Exposures: A mean (SD) 184.3 (66.0) days of ISS spaceflight missions.

Main outcomes and measures: Dural venous sinus volumes before and after spaceflight.

Results: A total of 12 astronauts (2 [16.67%] women; 10 [83.33%] men), with a mean (SD) age of 47.8 (5.8) years, were included. Overall, 4 astronauts (33.33%) met the diagnostic criteria for SANS. No dural venous sinus thrombosis was detected for any astronaut. Astronauts with SANS had significantly greater median (range) preflight to postflight increases in volume vs astronauts without SANS for all 3 venous sinus structures: superior sagittal sinus (13.40% [8.70% to 17.47%] vs -2.66% [-15.84% to 5.31%,]; P = .004), right transverse/sigmoid sinus (17.15% [7.63% to 30.08%] vs 0.77% [-14.98% to 15.12%]; P = .02), and left transverse/sigmoid sinus (9.40% [5.20% to 15.50%] vs -1.40% [-14.20% to 12.50%]; P = .03). There was a positive correlation between the neuroradiologist's evaluation and the semiautomated method for the superior sagittal sinus (rpb = 0.64; P = .02) and the right transverse/sigmoid sinus (rpb = 0.58; P = .050).

Conclusions and relevance: These findings, in conjunction with the growing body of evidence of abnormal blood flow dynamics during spaceflight, suggest an association between intracranial venous congestion and SANS. Thus, there is an implication that individuals with increased venous sinus compliance may be at increased risk of developing SANS. These findings should be confirmed in a larger astronaut population and may contribute to understanding disorders of intracranial venous outflow on Earth.

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Conflict of interest statement

Conflict of Interest Disclosures: None reported.

Figures

Figure 1.
Figure 1.. Image Analysis Workflow
MNI indicates Montreal Neurological Institute; MRI, magnetic resonance imaging. aRadiologist was masked to astronauts’ spaceflight-associated neuro-ocular syndrome status.
Figure 2.
Figure 2.. Preflight to Postflight Percentage Changes in Venous Sinus Volumes for the Superior Sagittal Sinus and Left and Right Transverse/Sigmoid Sinuses for Astronauts With and Without Spaceflight-Associated Neuro-Ocular Syndrome (SANS)
The boxes indicate the IQR, with the line in each box representing the median and the edges representing the limits of the IQR. The whiskers indicate 1.5 times the IQR, and the open circles indicate data points from 1.5 to 3.0 times the IQR.
Figure 3.
Figure 3.. Three-Dimensional Reconstructions of the Preflight and Postflight Venograms for an Astronaut with Spaceflight-Associated Neuro-Ocular Syndrome (SANS) and an Astronaut Without SANS
These images were created using RadiAnt DICOM Viewer, version 2020.2.2 (Medixant).
See this image and copyright information in PMC

References

    1. Lee AG, Mader TH, Gibson CR, et al. . Spaceflight associated neuro-ocular syndrome (SANS) and the neuro-ophthalmologic effects of microgravity: a review and an update. NPJ Microgravity. 2020;6:7. doi:10.1038/s41526-020-0097-9 - DOI - PMC - PubMed
    1. Marshall-Goebel K, Laurie SS, Alferova IV, et al. . Assessment of jugular venous blood flow stasis and thrombosis during spaceflight. JAMA Netw Open. 2019;2(11):e1915011. doi:10.1001/jamanetworkopen.2019.15011 - DOI - PMC - PubMed
    1. Auñón-Chancellor SM, Pattarini JM, Moll S, Sargsyan A. Venous thrombosis during spaceflight. N Engl J Med. 2020;382(1):89-90. doi:10.1056/NEJMc1905875 - DOI - PubMed
    1. Tustison NJ, Avants BB, Cook PA, et al. . N4ITK: improved N3 bias correction. IEEE Trans Med Imaging. 2010;29(6):1310-1320. doi:10.1109/TMI.2010.2046908 - DOI - PMC - PubMed
    1. Collingnon A, Maes F, Delaere D, Vandermeulen D, Suetens P, Marchal G. Automated multi-modality image registration based on information theory. In: Bizais Y, Barillot C, Di Paola R, eds. Information Processing in Medical Imaging. Kluwer Academic Publishers; 1995:263-274.

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