Forensic pathological observations on fatal injuries to the brain stem and/or upper cervical spinal cord in traffic accidents.

A retrospective study was performed on 149 forensic autopsy cases (12 in Kanazawa and 137 in Munich) of brain stem and/or upper cervical spinal cord (UCSC) injuries as a result of traffic accidents. Pedestrians were the most common type of victims, followed by car drivers. Eleven of the 12 Kanazawa victims were pedestrians. The total ratio of pedestrian victims gradually increased with age. The ponto-medullary junction was the most frequently injured site. A total of 146 cases demonstrated basal skull fractures and/or dislocation of the upper cervical joints: atlanto-occipital joint, atlanto-axial joint, or the joint between the 2nd and 3rd cervical vertebrae. However, in three cases, hyperextension of the neck unexpectedly caused brain stem injury neither associated with basal skull fracture nor with cervical dislocation. Intraventricular haemorrhage was found in 96 cases, suggesting a common feature associated with brain stem and/or UCSC injury. A tear of the basilar artery and that of the carotid artery was found in 17 and 20 cases respectively. A total of 39 victims demonstrated a blood alcohol concentration of over 0.5 mg/ml, and hyperextension of the neck occurred more frequently in these cases. In spite of the marked predominance of immediate death (138 cases), 11 cases (nine of brain stem injury and two of UCSC injury) had unexpected survival times of from 45 min to 12 h.