PMID- 29492564
OWN - NLM
STAT- MEDLINE
DCOM- 20180712
LR  - 20180712
IS  - 0065-1419 (Print)
IS  - 0065-1419 (Linking)
VI  - 126
DP  - 2018
TI  - Spaceflight-Induced Visual Impairment and Globe Deformations in Astronauts Are 
      Linked to Orbital Cerebrospinal Fluid Volume Increase.
PG  - 215-219
LID - 10.1007/978-3-319-65798-1_44 [doi]
AB  - OBJECTIVE: Most of the astronauts onboard the International Space Station (ISS) 
      develop visual impairment and ocular structural changes that are not fully 
      reversible upon return to earth. Current understanding assumes that the so-called 
      visual impairments/intracranial pressure (VIIP) syndrome is caused by cephalad 
      vascular fluid shift. This study assesses the roles of cerebrospinal fluid (CSF) 
      and intracranial pressure (ICP) in VIIP. MATERIALS AND METHODS: Seventeen 
      astronauts, 9 who flew a short-duration mission on the space shuttle (14.1 days 
      [SD 1.6]) and 7 who flew a long-duration mission on the ISS (188 days [SD 22]) 
      underwent MRI of the brain and orbits to assess the pre-to-post spaceflight 
      changes in four categories: VIIP severity measures: globe flattening and nerve 
      protrusion; orbital and ventricular CSF volumes; cortical gray and white matter 
      volumes; and MR-derived ICP (MRICP). RESULTS: Significant pre-to-post-flight 
      increase in globe flattening and optic nerve protrusion occurred only in the 
      long-duration cohort (0.031 [SD 0.019] vs -0.001 [SD 0.006], and 0.025 [SD 0.013] 
      vs 0.001 [SD 0.006]; p < 0.00002 respectively). The increased globe deformations 
      were associated with significant increases in orbital and ventricular CSF 
      volumes, but not with increased tissue vascular fluid content. Additionally, a 
      moderate increase in MRICP of 6 mmHg was observed in only two ISS astronauts with 
      large ocular structure changes. CONCLUSIONS: These findings are evidence for the 
      primary role of CSF and a lesser role for intracranial cephalad fluid-shift in 
      the formation of VIIP. VIIP is caused by a prolonged increase in orbital CSF 
      spaces that compress the globes' posterior pole, even without a large increase in 
      ICP.
FAU - Alperin, Noam
AU  - Alperin N
AD  - Department of Radiology, Miller School of Medicine, University of Miami, Miami, 
      FL, USA. Nalperin@med.miami.edu.
AD  - Alperin noninvasive diagnostics, Miami, FL, USA. Nalperin@med.miami.edu.
FAU - Bagci, Ahmet M
AU  - Bagci AM
AD  - Department of Radiology, Miller School of Medicine, University of Miami, Miami, 
      FL, USA.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - Austria
TA  - Acta Neurochir Suppl
JT  - Acta neurochirurgica. Supplement
JID - 100962752
SB  - IM
MH  - Adult
MH  - *Astronauts
MH  - Brain/diagnostic imaging
MH  - Cerebrospinal Fluid/*physiology
MH  - Cohort Studies
MH  - Eye/diagnostic imaging
MH  - Fluid Shifts/*physiology
MH  - Gray Matter/diagnostic imaging
MH  - Humans
MH  - Intracranial Hypertension/diagnostic imaging/etiology/*physiopathology
MH  - Intracranial Pressure/*physiology
MH  - Magnetic Resonance Imaging
MH  - Middle Aged
MH  - Optic Nerve/diagnostic imaging
MH  - Orbit/diagnostic imaging
MH  - *Space Flight
MH  - Vision Disorders/diagnostic imaging/etiology/*physiopathology
MH  - White Matter/diagnostic imaging
OTO - NOTNLM
OT  - Cephalad fluid shift
OT  - Globe flattening
OT  - Optic nerve protrusion
OT  - Quantitative MRI
OT  - Visual impairment/intracranial pressure syndrome
EDAT- 2018/03/02 06:00
MHDA- 2018/07/13 06:00
CRDT- 2018/03/02 06:00
PHST- 2018/03/02 06:00 [entrez]
PHST- 2018/03/02 06:00 [pubmed]
PHST- 2018/07/13 06:00 [medline]
AID - 10.1007/978-3-319-65798-1_44 [doi]
PST - ppublish
SO  - Acta Neurochir Suppl. 2018;126:215-219. doi: 10.1007/978-3-319-65798-1_44.