Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012 - McCrory, P; Meeuwisse, W H; Aubry, M; Cantu, B; Dvorák, J; Echemendia, R J; Engebretsen, L; Johnston, K; Kutcher, J S; Raftery, M; Sills, A; Benson, B W; Davis, Ga; Ellenbogen, R G; Guskiewicz, K; Herring, Sa; Iverson, G L; Jordan, B D; Kissick, J; McCrea, M; McIntosh, A S; Maddocks, D; Makdissi, M; Purcell, L; Putukian, M; Schneider, K; Tator, C H; Turner, M (Br J Sports Med, 2013)