title: Minor head trauma in soccer and serum levels of S100B.
abstract: OBJECTIVE
  To compare the serum levels of S100B after head trauma with the effect of heading, high-intensity exercise, and playing in a league match. Heading and head trauma in soccer have been suspected to cause brain impairment. The protein S100B is a marker of acute neuronal tissue damage.
  
  
  METHODS
  Baseline S100B was measured in 535 Norwegian professional soccer players. Two hundred twenty-eight head impacts were registered from 352 league matches. Three teams (n = 48) performed a high-intensity exercise session without heading and a low-intensity session with heading exercises. A blood sample was drawn from each participant within 1 hour (B1) after the session, and another sample (B12) was drawn after a match or training session. The players were assigned to four groups: Head Impact (n = 65), Match Control (match participants without head impact, n = 49), High-intensity Exercise (n = 35), and Heading (n = 36).
  
  
  RESULTS
  Serum S100B increased from baseline to B1 for all groups. The increase for the match groups (Head Impact and Match Control) was significantly higher than for both training groups. However, no significant differences between the Head Impact and Match Control groups or between the two training groups were found. A total of 39 players (33.9%) had elevated B1 values (>/=0.12 ng/ml) after a match, but these findings were equally distributed between the Match Control and Head Impact groups.
  
  
  CONCLUSIONS
  Both soccer training and soccer matches cause a transient increase in S100B. There is a possible additive effect of activity with high intensity and heading, but minor head impacts do not seem to cause an additional increase.
authors.affiliation: Department of Sports Medicine, Oslo Sports Trauma and Research Center, The Norwegian School of Sports Sciences, Oslo, Norway.
authors.forename: Truls Martin
authors.initials: TM
authors.lastname: Straume-Naesheim
authors.forename: Thor Einar
authors.initials: TE
authors.lastname: Andersen
authors.forename: Marianne
authors.initials: M
authors.lastname: Jochum
authors.forename: Jiri
authors.initials: J
authors.lastname: Dvorak
authors.forename: Roald
authors.initials: R
authors.lastname: Bahr
mesh_terms: D000293:Adolescent; D000328:Adult; D015444:Exercise / Q000502:physiology*; D005500:Follow-Up Studies; D016489:Head Injuries, Closed / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008297:Male; D009414:Nerve Growth Factors / Q000097:blood*; D011446:Prospective Studies; D012307:Risk Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood*; D012916:Soccer / Q000293:injuries* / Q000502:physiology*; D015599:Trauma Severity Indices
chemical_list: D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human