S100B and Headache: Subjects, that continued playing with headaches (Table 1, S4) after an occurred head injury (x = 0.50) in 50% of the times or more (T1), had higher S100-B titers (r = 0.592; n = 9; mean: 0.05; 95%-CI [0.04;0.06]), compared to subjects, that continued playing in less than 50% of the times (n = 6; mean: 0.04; 95%-CI [0.03;0.05]).