Quantitative magnetic resonance image assessment of the optic nerve and surrounding sheath after spaceflight
| Autor: | Jesse J. Rohr, Michael B. Stenger, Robert Ploutz-Snyder, Austin M. Sass, Karina Marshall-Goebel, Bryn A. Martin, C. Ross Ethier, Brandon R. Macias, Stuart Sater |
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| Rok vydání: | 2020 |
| Předmět: |
Physics and Astronomy (miscellaneous)
lcsh:Biotechnology Materials Science (miscellaneous) Medicine (miscellaneous) Distension Spaceflight Biochemistry Genetics and Molecular Biology (miscellaneous) Article lcsh:Physiology law.invention 03 medical and health sciences 0302 clinical medicine law lcsh:TP248.13-248.65 medicine Intracranial pressure lcsh:QP1-981 Cerebrospinal fluid dynamics medicine.diagnostic_test Weightlessness business.industry Magnetic resonance imaging Agricultural and Biological Sciences (miscellaneous) Vision disorders Space and Planetary Science Optic nerve diseases 030221 ophthalmology & optometry Optic nerve Nuclear medicine business Biomedical engineering Optic Disc Edema 030217 neurology & neurosurgery Neuroscience |
| Zdroj: | npj Microgravity, Vol 6, Iss 1, Pp 1-9 (2020) NPJ Microgravity |
| ISSN: | 2373-8065 |
| DOI: | 10.1038/s41526-020-00119-3 |
| Popis: | A subset of long-duration spaceflight astronauts have experienced ophthalmic abnormalities, collectively termed spaceflight-associated neuro-ocular syndrome (SANS). Little is understood about the pathophysiology of SANS; however, microgravity-induced alterations in intracranial pressure (ICP) due to headward fluid shifts is the primary hypothesized contributor. In particular, potential changes in optic nerve (ON) tortuosity and ON sheath (ONS) distension may indicate altered cerebrospinal fluid dynamics during weightlessness. The present longitudinal study aims to provide a quantitative analysis of ON and ONS cross-sectional areas, and ON deviation, an indication of tortuosity, before and after spaceflight. Ten astronauts undergoing ~6-month missions on the International Space Station (ISS) underwent high-resolution magnetic resonance imaging (MRI) preflight and at five recovery time points extending to 1 year after return from the ISS. The mean changes in ON deviation, ON cross-sectional area, and ONS cross-sectional area immediately post flight were −0.14 mm (95% CI: −0.36 to 0.08, Bonferroni-adjusted P = 1.00), 0.13 mm2 (95% CI −0.66 to 0.91, Bonferroni-adjusted P = 1.00), and −0.22 mm2 (95% CI: −1.78 to 1.34, Bonferroni-adjusted P = 1.00), respectively, and remained consistent during the recovery period. Terrestrially, ONS distension is associated with increased ICP; therefore, these results suggest that, on average, ICP was not pathologically elevated immediately after spaceflight. However, a subject diagnosed with optic disc edema (Frisen Grade 1, right eye) displayed increased ONS area post flight, although this increase is relatively small compared to clinical populations with increased ICP. Advanced quantitative MRI-based assessment of the ON and ONS could help our understanding of SANS and the role of ICP. |
| Databáze: | OpenAIRE |
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