Mathematical simulation of gliding contusions.

Abstract A gliding contusion in the acute phase is characterized by a streaklike hemorrhage of venous origin situated subcortically in a paramedial convolution. In later stages perivascular necrosis may develop. This type of injury is caused by head angular acceleration and is often seen in traffic casualties when the head has hit the steering wheel, the dashboard or the windshield. The deformation of the brain matter close to the superior sagittal sinus has been simulated by means of a mathematical viscoelastic model in order to clarify the genesis of the gliding contusions. The blood vessels in the brain matter will be strained as a consequence of the brain deformation which results from head angular acceleration. The highest values of the strain occur subcortically where the blood vessels are injured first. The tolerance levels for gliding contusions have been determined. The calculations which were based on experiments regarding the dynamic properties of the superior cerebral veins and on two alternative injury criteria proposed, indicate that a gliding contusion is not likely to arise if the maximal angular acceleration does not exceed 4500 rad/sec2 or the change in angular velocity does not exceed 70 rad/sec.