Brain injury without head injury. Some physics of automobile collisions with particular reference to brain injuries occurring without physical head trauma.
The classic kinematic formula, a=(v2-v0(2))/2s, relating deceleration to change of velocity and displacement during the change, is used to determine the acceleration experienced by the occupants of motor vehicles (and their heads) during collisions. The displacement, s, of the occupants in the accident can often be determined from the deformation of the wreckage, thus yielding this critical information about potential for brain injury. Data from 15 accidents are assembled and approximate accelerations computed. At the same time medical and neuropsychological data have been obtained for each of the accident victims. These accidents and the associated victims (except for one special case) have been selected because in no case has the victim suffered a direct head-contact injury. Nevertheless, all suffered neurologic and/or neuropsychological injuries typical of patients with closed head trauma. The paper demonstrates that with decelerations from 30 g to more than 200 g yet without skull impacts, brain damage results.
Varney
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Psychology Service, VA Medical Center, Iowa City, IA 52246, USA.
Varney
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