PONTOMEDULLARY RENT - A SPECIFIC TYPE OF PRIMARY BRAIN-STEM TRAUMATICINJURY

Pontomedullary rent is a primary injury to the brainstem that may occu r in high-speed accidents. We present a series of 13 autopsies with co mplete or partial pontomedullary rent documented over a 12-year period . Of the 13 cases, seven had associated basal skull fractures and thre e had fractures of the cervical spine. In five patients, the rent was an isolated traumatic lesion of the brain. While pontomedullary rents are mostly caused by traumatic craniocervical hyperextension, some aut hors feel that these rents could be a form of diffuse axonal injury ca used by angular acceleration of the head. In this study, two patients had documented features of diffuse axonal injury. More than one mechan ism of injury could therefore be involved. Pontomedullary rents could be underdiagnosed, as partial rent is compatible with survival and, wh en there are no associated fractures, these tears may be attributed to artifactual damage occurring during removal of the brain at autopsy.