title: White matter hyperintensities and hypobaric exposure.
abstract: OBJECTIVE
  Demonstrate that occupational exposure to nonhypoxic hypobaria is associated with subcortical white matter hyperintensities (WMHs) on fluid-attenuated inversion recovery magnetic resonance imaging (MRI).
  
  
  METHODS
  Eighty-three altitude chamber personnel (PHY), 105 U-2 pilots (U2P), and 148 age- controlled and health-matched doctorate degree controls (DOC) underwent high-resolution MRI. Subcortical WMH burden was quantified as count and volume of subcortical WMH lesions after transformation of images to the Talairach atlas-based stereotactic frame.
  
  
  RESULTS
  Subcortical WMHs were more prevalent in PHY (volume p = 0.011/count p = 0.019) and U2P (volume p < 0.001/count p < 0.001) when compared to DOC, whereas PHY were not significantly different than U2P.
  
  
  CONCLUSIONS
  This study provides strong evidence that nonhypoxic hypobaric exposure may induce subcortical WMHs in a young, healthy population lacking other risk factors for WMHs and adds this occupational exposure to other environmentally related potential causes of WMHs. Ann Neurol 2014;76:719-726.
authors.affiliation: US Air Force School of Aerospace Medicine, Aerospace Medicine Consultation Division, Wright-Patterson Air Force Base, OH; Department of Neurology, University of Texas Health Sciences Center, San Antonio, TX; Department of Neurology, 59th Medical Wing, Lackland Air Force Base, TX.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: McGuire
authors.forename: Paul M
authors.initials: PM
authors.lastname: Sherman
authors.forename: S Andrea
authors.initials: SA
authors.lastname: Wijtenburg
authors.forename: Laura M
authors.initials: LM
authors.lastname: Rowland
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Grogan
authors.forename: John H
authors.initials: JH
authors.lastname: Sladky
authors.forename: Andrew Y
authors.initials: AY
authors.lastname: Robinson
authors.forename: Peter V
authors.initials: PV
authors.lastname: Kochunov
mesh_terms: D000328:Adult; D000375:Aging; D000399:Air Pressure; D000531:Altitude; D001273:Atmosphere Exposure Chambers; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002534:Hypoxia, Brain / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D016273:Occupational Exposure; D066127:White Matter / Q000473:pathology*