title: Evaluation of White Matter Injury Patterns Underlying Neuropsychiatric Symptoms after Mild Traumatic Brain Injury.
abstract: OBJECTIVE
  To determine if a central axonal injury underlies neuropsychiatric symptoms after mild traumatic brain injury (mTBI) by using tract-based spatial statistics analysis of diffusion-tensor images.
  
  
  METHODS
  The institutional review board approved this study, with waiver of informed consent. Diffusion-tensor imaging and serial neurocognitive testing with the Immediate Post-Concussion Assessment and Cognitive Testing evaluation were performed in 45 patients with mTBI (38 with irritability, 32 with depression, and 18 with anxiety). Control subjects consisted of 29 patients with mTBI without neuropsychiatric symptoms. Fractional anisotropy and diffusivity maps were analyzed by using tract-based spatial statistics with a multivariate general linear model. Diffusion-tensor imaging findings were correlated with symptom severity, neurocognitive test scores, and time to recovery with the Pearson correlation coefficient.
  
  
  RESULTS
  Compared with control subjects, patients with mTBI and depression had decreased fractional anisotropy in the superior longitudinal fasciculus (P = .006), white matter around the nucleus accumbens (P = .03), and anterior limb of the internal capsule (P = .02). Patients with anxiety had diminished fractional anisotropy in the vermis (P = .04). No regions of significantly decreased fractional anisotropy were seen in patients with irritability relative to control subjects. Injury in the region of the nucleus accumbens inversely correlated with recovery time in patients with depression (r = -0.480, P = .005).
  
  
  CONCLUSIONS
  Unique white matter injury patterns were seen for two major posttraumatic neuropsychiatric symptoms. Injury to the cerebellar vermis in patients with mTBI and anxiety may indicate underlying dysfunction in primitive fear conditioning circuits in the cerebellum. Involvement of the nucleus accumbens in depression after mTBI may suggest an underlying dysfunctional reward circuit that affects the prognosis in these patients.
authors.affiliation: From the Department of Radiology, Division of Neuroradiology, UPMC Presbyterian Hospital, University of Pittsburgh Medical Center, 200 Lothrop St, Presby South Tower, 3rd Floor, Suite 3950, Pittsburgh, PA 15213.
authors.forename: Lea M
authors.initials: LM
authors.lastname: Alhilali
authors.affiliation: From the Department of Radiology, Division of Neuroradiology, UPMC Presbyterian Hospital, University of Pittsburgh Medical Center, 200 Lothrop St, Presby South Tower, 3rd Floor, Suite 3950, Pittsburgh, PA 15213.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Delic
authors.affiliation: From the Department of Radiology, Division of Neuroradiology, UPMC Presbyterian Hospital, University of Pittsburgh Medical Center, 200 Lothrop St, Presby South Tower, 3rd Floor, Suite 3950, Pittsburgh, PA 15213.
authors.forename: Serter
authors.initials: S
authors.lastname: Gumus
authors.affiliation: From the Department of Radiology, Division of Neuroradiology, UPMC Presbyterian Hospital, University of Pittsburgh Medical Center, 200 Lothrop St, Presby South Tower, 3rd Floor, Suite 3950, Pittsburgh, PA 15213.
authors.forename: Saeed
authors.initials: S
authors.lastname: Fakhran
mesh_terms: D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D001007:Anxiety / Q000209:etiology; D001930:Brain Injuries / Q000150:complications*; D002648:Child; D003863:Depression / Q000209:etiology; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D020772:Internal Capsule / Q000293:injuries; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009714:Nucleus Accumbens / Q000293:injuries; D011379:Prognosis; D066127:White Matter / Q000293:injuries*