White matter hyperintensities and hypobaric exposure

Ann Neurol. 2014 Nov;76(5):719-26. doi: 10.1002/ana.24264. Epub 2014 Sep 17.


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.

Interpretation: 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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Aging
  • Air Pressure*
  • Altitude
  • Atmosphere Exposure Chambers
  • Female
  • Follow-Up Studies
  • Humans
  • Hypoxia, Brain / pathology*
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Military Personnel
  • Occupational Exposure
  • White Matter / pathology*