elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

MRI-derived diffusion parameters in the human optic nerve and its surrounding sheath during head-down tilt

Gerlach, Darius A. and Marshall-Goebel, Karina and Hasan, Khader M. and Kramer, Larry A. and Alperin, Noam and Rittweger, Jörn (2017) MRI-derived diffusion parameters in the human optic nerve and its surrounding sheath during head-down tilt. npj Microgravity, 3 (18). Nature Publishing Group. DOI: 10.1038/s41526-017-0023-y ISSN 2373-8065

[img] PDF
1MB

Official URL: http://www.nature.com/articles/s41526-017-0023-y

Abstract

More than half of astronauts present with significant neuro-ophthalmic findings during 6-month missions onboard the International Space Station. Although the underlying cause of this Microgravity Ocular Syndrome is currently unknown, alterations in cerebrospinal fluid dynamics within the optic nerve sheath may play a role. In the presented study, diffusion tensor imaging was used to assess changes in diffusivity of the optic nerve and its surrounding sheath during head-down tilt, a ground-based model of microgravity. Nine healthy male subjects (mean age ± SD: 25 ± 2.4 years; mean body mass index ± SD: 24.1 ± 2.4 kg/m2) underwent 5 head-down tilt conditions: −6°,−12°, −18°,−12° and 1% CO2, and −12° and lower body negative pressure. Mean diffusivity, fractional anisotropy, axial diffusivity, radial diffusivity were quantified in the left and right optic nerves and surrounding sheaths at supine baseline and after 4.5 h head-down tilt for each condition. In the optic nerve sheath, mean diffusivity was increased with all head-down tilt conditions by (Best Linear Unbiased Predictors) 0.147 (SE: 0.04) × 10−3 mm2/s (P < 0.001), axial diffusivity by 0.188 (SE: 0.064) × 10−3 mm2/s (P < 0.001), and radial diffusivity by 0.126 (SE: 0.04) × 10−3 mm2/s (P = 0.0019). Within the optic nerve itself, fractional anisotropy was increased by 0.133 (SE: 0.047) (P = 0.0051) and axial diffusivity increased by 0.135 (SE: 0.08) × 10−3 mm2/s (P = 0.014) during head-down tilt, whilst mean diffusivity and radial diffusivity were unaffected (P > 0.3). These findings could be due to increased perioptic cerebral spinal fluid hydrodynamics during head-down tilt, as well as increased cerebral spinal fluid volume and movement within the optic nerve sheath.

Item URL in elib:https://elib.dlr.de/112885/
Document Type:Article
Title:MRI-derived diffusion parameters in the human optic nerve and its surrounding sheath during head-down tilt
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Gerlach, Darius A.darius.gerlach (at) dlr.dehttps://orcid.org/0000-0001-7044-6065
Marshall-Goebel, KarinaNeural Systems Group, Massachusetts General Hospital, Harvard Medical School,https://orcid.org/0000-0002-5240-7625
Hasan, Khader M.university of texas health science at houston-mcgovern medical schoolUNSPECIFIED
Kramer, Larry A.university of texas health science at houston-mcgovern medical schoolUNSPECIFIED
Alperin, NoamDepartment of Radiology, University of Miami, Miami, FL, USAUNSPECIFIED
Rittweger, Jörnjoern.rittweger (at) dlr.deUNSPECIFIED
Date:21 June 2017
Journal or Publication Title:npj Microgravity
Refereed publication:Yes
Open Access:Yes
Gold Open Access:Yes
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:3
DOI :10.1038/s41526-017-0023-y
Publisher:Nature Publishing Group
ISSN:2373-8065
Status:Published
Keywords:DTI, microgravity, intracranial pressure, head down tilt, optic nerve sheath
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Research under Space Conditions
DLR - Research area:Raumfahrt
DLR - Program:R FR - Forschung unter Weltraumbedingungen
DLR - Research theme (Project):R - Vorhaben Artificial Gravity
Location: Köln-Porz
Institutes and Institutions:Institute of Aerospace Medicine > Space Physiology
Institute of Aerospace Medicine > Cardiovascular Medicine in Aerospace
Deposited By: Gerlach, Darius
Deposited On:28 Jun 2017 12:56
Last Modified:17 Nov 2018 05:02

Repository Staff Only: item control page

Browse
Search
Help & Contact
Information
electronic library is running on EPrints 3.3.12
Copyright © 2008-2017 German Aerospace Center (DLR). All rights reserved.