title: Detection of blast-related traumatic brain injury in U.S. military personnel.
abstract: BACKGROUND
  Blast-related traumatic brain injuries have been common in the Iraq and Afghanistan wars, but fundamental questions about the nature of these injuries remain unanswered.
  
  
  METHODS
  We tested the hypothesis that blast-related traumatic brain injury causes traumatic axonal injury, using diffusion tensor imaging (DTI), an advanced form of magnetic resonance imaging that is sensitive to axonal injury. The subjects were 63 U.S. military personnel who had a clinical diagnosis of mild, uncomplicated traumatic brain injury. They were evacuated from the field to the Landstuhl Regional Medical Center in Landstuhl, Germany, where they underwent DTI scanning within 90 days after the injury. All the subjects had primary blast exposure plus another, blast-related mechanism of injury (e.g., being struck by a blunt object or injured in a fall or motor vehicle crash). Controls consisted of 21 military personnel who had blast exposure and other injuries but no clinical diagnosis of traumatic brain injury.
  
  
  RESULTS
  Abnormalities revealed on DTI were consistent with traumatic axonal injury in many of the subjects with traumatic brain injury. None had detectable intracranial injury on computed tomography. As compared with DTI scans in controls, the scans in the subjects with traumatic brain injury showed marked abnormalities in the middle cerebellar peduncles (P<0.001), in cingulum bundles (P=0.002), and in the right orbitofrontal white matter (P=0.007). In 18 of the 63 subjects with traumatic brain injury, a significantly greater number of abnormalities were found on DTI than would be expected by chance (P<0.001). Follow-up DTI scans in 47 subjects with traumatic brain injury 6 to 12 months after enrollment showed persistent abnormalities that were consistent with evolving injuries.
  
  
  CONCLUSIONS
  DTI findings in U.S. military personnel support the hypothesis that blast-related mild traumatic brain injury can involve axonal injury. However, the contribution of primary blast exposure as compared with that of other types of injury could not be determined directly, since none of the subjects with traumatic brain injury had isolated primary blast injury. Furthermore, many of these subjects did not have abnormalities on DTI. Thus, traumatic brain injury remains a clinical diagnosis. (Funded by the Congressionally Directed Medical Research Program and the National Institutes of Health; ClinicalTrials.gov number, NCT00785304.).
authors.affiliation: Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Mac Donald
authors.forename: Ann M
authors.initials: AM
authors.lastname: Johnson
authors.forename: Dana
authors.initials: D
authors.lastname: Cooper
authors.forename: Elliot C
authors.initials: EC
authors.lastname: Nelson
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: Werner
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Shimony
authors.forename: Abraham Z
authors.initials: AZ
authors.lastname: Snyder
authors.forename: Marcus E
authors.initials: ME
authors.lastname: Raichle
authors.forename: John R
authors.initials: JR
authors.lastname: Witherow
authors.forename: Raymond
authors.initials: R
authors.lastname: Fang
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Flaherty
authors.forename: David L
authors.initials: DL
authors.lastname: Brody
mesh_terms: D000328:Adult; D055826:Afghan Campaign 2001-; D001753:Blast Injuries / Q000150:complications* / Q000473:pathology; D001921:Brain / Q000473:pathology*; D001930:Brain Injuries / Q000150:complications / Q000175:diagnosis; D016022:Case-Control Studies; D020833:Diffuse Axonal Injury / Q000175:diagnosis* / Q000209:etiology; D056324:Diffusion Tensor Imaging; D006801:Humans; D054542:Iraq War, 2003-2011; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D014481:United States; D055815:Young Adult