title: One-year follow-up of patients with mild traumatic brain injury: occurrence of post-traumatic stress-related symptoms at follow-up and serum levels of cortisol, S-100B and neuron-specific enolase in acute phase.
abstract: OBJECTIVE
  To investigate serum levels of cortisol (a biochemical marker of stress), S-100B and neuron-specific enolase (two biochemical markers of brain tissue injury), in acute phase in mild traumatic brain injury patients and the occurrence of post-traumatic stress-related symptoms 1 year after the trauma.
  
  
  METHODS
  Blood samples were taken in patients (n = 88) on admission and approximately 7 hours later for analysis. Occurrence of post-traumatic stress-related symptoms was assessed for 69 patients using items from the Impact of Event Scale questionnaire (IES) at follow-up at 15 +/- 4 months after the injury.
  
  
  RESULTS
  Serum levels of cortisol were more increased in the first sample (cortisol/1, 628.9 +/- 308.9 nmol L-1) than in the second blood sample (cortisol/2, 398.2 +/- 219.4 nmol L-1). The difference between these samples was statistically significant (p < 0.001). Altogether 12 patients (17%) showed post-traumatic stress related symptoms at the time of the follow-up. Stepwise forward logistic regression analysis of symptoms and serum concentrations of markers revealed that only S-100B in the second sample was statistically significantly (p < 0.05) associated to symptoms (three symptoms of the avoidance sub-set of IES).
  
  
  CONCLUSIONS
  A major increase in serum concentrations of cortisol indicates that high stress levels were reached by the patients, in particular shortly ( approximately 3 hours) after the trauma. The association between the occurrence of post-traumatic stress related symptoms and serum levels of S-100B (generally considered as a biochemical marker of brain injury) seem to reflect the complexity of interactions between brain tissue injury and the ensemble of stress reactions.
authors.affiliation: Department of Community Medicine and Rehabilitation, Umeå University Hospital, Umeå University, Sweden. peter.sojka@clinphys.umu.se
authors.forename: Peter
authors.initials: P
authors.lastname: Sojka
authors.forename: Britt-Marie
authors.initials: BM
authors.lastname: Stålnacke
authors.forename: Ulf
authors.initials: U
authors.lastname: Björnstig
authors.forename: Kurt
authors.initials: K
authors.lastname: Karlsson
mesh_terms: D000208:Acute Disease; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001930:Brain Injuries / Q000097:blood / Q000523:psychology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D009414:Nerve Growth Factors / Q000097:blood*; D010751:Phosphopyruvate Hydratase / Q000097:blood*; D011446:Prospective Studies; D012044:Regression Analysis; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood*; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis*; D013997:Time Factors
chemical_list: D015415:Biomarkers; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D010751:Phosphopyruvate Hydratase; D006854:Hydrocortisone