title: Mild traumatic brain injury: longitudinal regional brain volume changes.
abstract: OBJECTIVE
  To investigate longitudinal changes in global and regional brain volume in patients 1 year after mild traumatic brain injury (MTBI) and to correlate such changes with clinical and neurocognitive metrics.
  
  
  METHODS
  This institutional review board-approved study was HIPAA compliant. Twenty-eight patients with MTBI (with 19 followed up at 1 year) with posttraumatic symptoms after injury and 22 matched control subjects (with 12 followed up at 1 year) were enrolled. Automated segmentation of brain regions to compute regional gray matter (GM) and white matter (WM) volumes was performed by using three-dimensional T1-weighted 3.0-T magnetic resonance imaging, and results were correlated with clinical metrics. Pearson and Spearman rank correlation coefficients were computed between longitudinal brain volume and neurocognitive scores, as well as clinical metrics, over the course of the follow-up period.
  
  
  RESULTS
  One year after MTBI, there was measurable global brain atrophy, larger than that in control subjects. The anterior cingulate WM bilaterally and the left cingulate gyrus isthmus WM, as well as the right precuneal GM, showed significant decreases in regional volume in patients with MTBI over the 1st year after injury (corrected P < .05); this was confirmed by means of cross-sectional comparison with data in control subjects (corrected P < .05). Left and right rostral anterior cingulum WM volume loss correlated with changes in neurocognitive measures of memory (r = 0.65, P = .005) and attention (r = 0.60, P = .01). At 1-year follow-up, WM volume in the left cingulate gyrus isthmus correlated with clinical scores of anxiety (Spearman rank correlation r = -0.68, P = .007) and postconcussive symptoms (Spearman rank correlation r = -0.65, P = .01).
  
  
  CONCLUSIONS
  These observations demonstrate structural changes to the brain 1 year after injury after a single concussive episode. Regional brain atrophy is not exclusive to moderate and severe traumatic brain injury but may be seen after mild injury. In particular, the anterior part of the cingulum and the cingulate gyrus isthmus, as well as the precuneal GM, may be distinctively vulnerable 1 year after MTBI.
authors.affiliation: Department of Radiology, New York University School of Medicine, 660 First Ave, 2nd Floor, New York, NY 10016, USA.
authors.forename: Yongxia
authors.initials: Y
authors.lastname: Zhou
authors.forename: Andrea
authors.initials: A
authors.lastname: Kierans
authors.forename: Damon
authors.initials: D
authors.lastname: Kenul
authors.forename: Yulin
authors.initials: Y
authors.lastname: Ge
authors.forename: Joseph
authors.initials: J
authors.lastname: Rath
authors.forename: Joseph
authors.initials: J
authors.lastname: Reaume
authors.forename: Robert I
authors.initials: RI
authors.lastname: Grossman
authors.forename: Yvonne W
authors.initials: YW
authors.lastname: Lui
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001284:Atrophy; D001930:Brain Injuries / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D013997:Time Factors