title: Chronic traumatic encephalopathy in professional sports: retrospective and prospective views.
abstract: OBJECTIVE
  The purposes of this paper are to review: (1) the history of chronic traumatic encephalopathy (CTE) in sports, (2) the similarities and differences between historic and current definitions of CTE, (3) recent epidemiology and cohort studies of CTE and (4) controversies regarding the current CTE positions.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Selective review of published articles relevant to CTE.
  
  
  RESULTS
  The current definitions of CTE have evolved from its original definition and now rely heavily on the post-mortem detection of hyperphosphorylated tau for diagnosis. As of 2013, there is a blended cohort of 110 professional athletes diagnosed with CTE. It is being assumed that concussions and/or sub-concussive impacts in contact sports are the sole cause of CTE.
  
  
  CONCLUSIONS
  There are multiple causes of abnormal tau protein deposition in the human brain and the pathogenesis of CTE may not be related solely to concussion and/or sub-concussive injury. In all likelihood, the causes of CTE are a multivariate, as opposed to a univariate, phenomenon.
authors.affiliation: Vanderbilt Sports Concussion Center .
authors.forename: Gary S
authors.initials: GS
authors.lastname: Solomon
authors.forename: Scott L
authors.initials: SL
authors.lastname: Zuckerman
mesh_terms: D000367:Age Factors; D056352:Athletes / Q000266:history / Q000706:statistics & numerical data*; D001265:Athletic Injuries / Q000453:epidemiology* / Q000266:history / Q000378:metabolism / Q000503:physiopathology; D020208:Brain Injury, Chronic / Q000453:epidemiology* / Q000266:history / Q000378:metabolism / Q000503:physiopathology; D018450:Disease Progression; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D019636:Neurodegenerative Diseases / Q000453:epidemiology* / Q000266:history / Q000503:physiopathology; D059906:Neuroimaging; D011379:Prognosis; D011446:Prospective Studies; D012189:Retrospective Studies; D016875:tau Proteins / Q000378:metabolism*
chemical_list: D016875:tau Proteins
keywords: Chronic traumatic encephalopathy; concussion; sports; traumatic brain injury