A simple mechanical model using a piston to produce localized cerebral contusions in pigs.

A simple mechanical model using a piston to produce localized cerebral contusions in pigs, is presented. The precision and reproducibility of the method are described by the biomechanical and pathological results. There are only pathological changes with haemorrhage and laceration close to the place of entry of the piston. The changes in the physiological parameters also indicate that the damage is focal. In this model, when kept intact, the dura mater offers considerable protection as no pathological changes in the brain are observed even when the energy at the time of the contusion is increased to twice the values which, when the dura is open, cause considerable damage.