title: Diffusion Tensor Imaging Findings in Post-Concussion Syndrome Patients after Mild Traumatic Brain Injury: A Systematic Review.
abstract: OBJECTIVE
  To review the evidence for the use of diffusion tensor imaging (DTI) parameters in the human brain as a diagnostic tool for and predictor of post-concussion syndrome (PCS) after a mild traumatic brain injury (mTBI).
  
  
  METHODS
  Systematic review.
  
  
  METHODS
  All relevant studies in AMED, Embase, MEDLINE, Ovid, PubMed, Scopus, and Web of Science through 20 May, 2016.
  
  
  METHODS
  Studies that analyze traditional DTI measures [fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD)] and the severity of PCS symptoms or the development of PCS in humans after an mTBI.
  
  
  METHODS
  Population studied, patient source, mTBI diagnosis method, PCS diagnosis method, DTI values measured, significant findings, and correlation between DTI findings and PCS.
  
  
  RESULTS
  Ten studies investigated correlations between DTI values and PCS symptom severity or between DTI values and the development of PCS in mTBI patients. Decreased FA and increased MD and RD were associated with the development and severity of PCS. AD was not found to change significantly. Brain regions found to have significant changes in DTI parameters varied from study to study, although the corpus callosum was most frequently cited as having abnormal DTI parameters in PCS patients.
  
  
  CONCLUSIONS
  DTI abnormalities correlate with PCS incidence and symptom severity, as well as indicate an increased risk of developing PCS after mTBI. Abnormal DTI findings should prompt investigation of the syndrome to ensure optimal symptom management at the earliest stages. Currently, there is no consensus in the literature about the use of one DTI parameter in a specific region of the brain as a biomarker for PCS because no definite trends for DTI parameters in PCS subjects have been identified. Further research is required to establish a standard biomarker for PCS.
authors.affiliation: Department of Surgery, Division of Neurosurgery, Injury Prevention Research Office, Saint Michael's Hospital , Toronto, ON , Canada.
authors.forename: Edrea
authors.initials: E
authors.lastname: Khong
authors.affiliation: Department of Surgery, Division of Neurosurgery, Injury Prevention Research Office, Saint Michael's Hospital , Toronto, ON , Canada.
authors.forename: Nicole
authors.initials: N
authors.lastname: Odenwald
authors.affiliation: Department of Surgery, Division of Neurosurgery, Injury Prevention Research Office, Saint Michael's Hospital , Toronto, ON , Canada.
authors.forename: Eyesha
authors.initials: E
authors.lastname: Hashim
authors.affiliation: Department of Surgery, Division of Neurosurgery, Injury Prevention Research Office, Saint Michael's Hospital , Toronto, ON , Canada.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Cusimano
keywords: biomarker; diffusion tensor imaging; mild traumatic brain injury; post-concussion syndrome; systematic review