BIOMECHANICAL ANALISYS OF FENCING RESPONSE IN TBI

MARTINES OSCAR; LAGGER IGNACIO; PACHA MARIA SOL; ORELLANA LUCAS; CALANDRA CRISTIAN; ERNST GLENDA

Houston

Congreso; 70th American Epilepsy Society Annual Meeting,; 2016

American Epilepsy Society

RATIONATE:Fencing response is defined as non a epileptic phenomenon that is a potential inmediate sequeale of concussive brain injury. Usually it begings within 2 seconds of impact associated with a phase of brief tonic stiffening followed by myoclonic jerking usually bilateral but often asimetrical. The pathophysiology is not well understanding. One theory postulated that the fast acceleration of the head by the impact stimulate the lateral vestibular nucleus triggering the motor response.OBJECTIVE:Our aim was to described the biomechanical analysis of fencing responseMETHODS:We analyzed 4 videos from YouTubeTM , that showed head trauma injury and then documented fencing response. We used Blender 2.77a to obtained the model of each person who presented the fencing response and then we obtained the trajectory of the impact with Tracker 4.93 software. We also analyzed the acceleration and the time of the impact.RESULT:After the analysis of the four cases, when we apply the Wayne State Tolerance Curve, we find out that in all of them the acceleration due to a knock or punch is much lower than the scale used to represent the curve (g acceleration around 10 gs or 98 m/s2), and the duration of the acceleration is far above the limits of the curve (between 30 to 60 ms). According to that, we consider that this curve does not fit precisely to the sport concussion cases that we are studying.Taking into consideration the Head Injury Criterion formula, with a time window of 15ms (HIC15) and a linear acceleration, we found that cases 2 and 3 are far over the limit of 700 (according to NHTSA), while case 1 is close to that limit and case 4 is far below. Anyway, for sport protection design, the HIC limit is set to 250 by the American Society for Testing and Materials (ASTM), so in this situation, the case 4 exceeds that limit.CONCLUSIONThe video analysis showed that a short duration and high acceleration impact produced fencing response. Due to the transient acute onset and presentation differ from the posttraumatic epilepsy wich requires time to generate an epilpeptogenic focus.