Role of Cerebrospinal Fluid in Spaceflight-induced Ocular Changes and Visual Impairment in Astronauts.

Role of Cerebrospinal Fluid in Spaceflight-induced Ocular Changes and Visual Impairment in Astronauts.

Radiology. 2017 Apr 21;:161981

Authors: Alperin N, Bagci AM, Oliu CJ, Lee SH, Lam BL

Abstract
Purpose To determine the respective roles of vascular and cerebrospinal fluids in spaceflight-induced vision impairment in astronauts, known as the visual impairment and intracranial pressure (VIIP) syndrome. Materials and Methods This retrospective study was approved by the National Aeronautics and Space Administration institutional review board and is HIPAA compliant. All subjects provided written informed consent. Magnetic resonance (MR) imaging data from nine astronauts (mean age, 46.9 years) who flew on the space shuttle (14.1 days ± 1.6 [standard deviation]) and seven astronauts (mean age, 46.1 years) who flew on the International Space Station (188 days ± 22) between 2010 and 2014 were used to quantify pre- to postflight changes in globe flattening and optic nerve protrusion. Automated quantitation was also used to measure pre- to postflight changes in orbital and ventricular cerebrospinal fluid volumes and in brain tissue volumes. Relationships between individual measures and differences between cohorts were assessed by using correlation and unpaired t test, respectively. Results Pre- to postflight increases in globe flattening and nerve protrusion were significant only in the long-duration cohort (0.031 ± 0.019 vs -0.001 ± 0.006 and 0.025 ± 0.013 vs 0.001 ± 0.006; P < .00002, respectively). The increases in globe flattening and nerve protrusion were associated with significant increases in orbital and ventricular cerebrospinal fluid volumes. In contrast, brain tissue volumes do not change or correlate with globe flattening and optic nerve protrusion. Conclusion These findings are evidence for a primary role for cerebrospinal fluid and a lesser role for brain volume changes in the formation of VIIP. (©) RSNA, 2017.

PMID: 28430554 [PubMed - as supplied by publisher]

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