Comparison of Dural Venous Sinus Volumes Before and After Flight in Astronauts With and Without Spaceflight-Associated Neuro-Ocular Syndrome.
JAMA Netw Open
; 4(10): e2131465, 2021 10 01.
Article
em En
| MEDLINE
| ID: mdl-34705011
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, andParticipants:
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 andMeasures:
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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Trombose dos Seios Intracranianos
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Voo Espacial
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Síndrome
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Transtornos da Visão
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Astronautas
Tipo de estudo:
Etiology_studies
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Incidence_studies
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Observational_studies
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Qualitative_research
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Risk_factors_studies
Limite:
Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
JAMA Netw Open
Ano de publicação:
2021
Tipo de documento:
Article