Survival after ponto-medullary junction trauma

Imaging Evaluation of Acute Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of morbidity and mortality worldwide. Imaging plays an important role in the evaluation, diagnosis, and triage of patients with TBI. Recent studies suggest that it also helps predict patient outcomes. TBI consists of multiple pathoanatomic entities. This article reviews the current state of TBI imaging including its indications, benefits and limitations of the modalities, imaging protocols, and imaging findings for each of these pathoanatomic entities. Also briefly surveyed are advanced imaging techniques, which include several promising areas of TBI research.

Pathology of head trauma

This article reviews the essential primary and secondary injuries attributable to traumatic brain injury (TBI) which causes one third of all injury deaths in the United States. Motor vehicle crashes, falls, assaults, guns, sports, and recreational activities are the major causes of TBI. Secondary peak incidences of TBI occur in infants and children and the elderly. Conditions that increase risk for accidents include alcoholism, prior head injury, prior meningitis, seizure disorders, mental retardation, and psychiatric disorders. However, gunshot wounds to the head are steadily increasing and since 1990 have caused more deaths each year than motor vehicle accidents. The incidence, severity, etiology, and specific types of injuries have been assessed in clinicopathologic studies of head injuries. The pathologic features of both the primary and secondary lesions attributed to TBI should be understood by anyone caring for head-injured patients. The computed tomography (CT) and magnetic resonance (MR) images mirror the pathologic abnormalities found in head trauma. Radiologists must accurately interpret the CT and MR images of injured patients. Forensic pathologists have long appreciated the characteristic focal lesions, such as coup and contracoup contusions, that occur in falls or vehicle accidents, but the understanding of diffuse injuries has been more elusive. Understanding the nature of the focal and diffuse injuries is critical to understanding the morbidity and mortality of brain injury.

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.

Traumatic ponto-medullary tear: a case report

The aim of this report is to demonstrate the correlation between an extremely short time acting but strong force leading to incomplete rupture of the ponto-medullary junction (PMJ) accompanied by rupture of the basilar artery. Potential mechanisms involved in a combined hyperextension and axial torsion of the head followed by characteristic lesions at the PMJ are discussed. A 33-year-old male suffered a blunt head injury following a blow to the head, i.e. a head-butt. Resuscitation was performed for 45 min without success. At post mortem, there was a superficial periorbital haematoma on the right and a deep soft tissue bruise in the right fronto-parieto-temporal area, but no evidence of skull or dens axis fracture. A deep tear at the ponto-medullary junction was identified with rupture of the basilar artery, whereas at the tip of the tear, i.e. the floor of the IVth ventricle, only a thin tissue layer of about 2 mm remained intact. In contrast to the severity of these lesions, only mild subarachnoid hemorrhage was observed, but the ventricular system was filled with blood clot resulting from the retrograde flow of subarachnoid hemorrhage.

Fatal injuries of the brain stem and/or upper cervical spinal cord in traffic accidents: nine autopsy cases

Nine forensic autopsy cases were studied. All had injuries of the brain stem and/or upper cervical spinal cord due to traffic accidents. Among the nine subjects, eight were pedestrians and one was a left, front seat occupant of a vehicle. Examination of these 9 cases revealed that three had ponto-medullary avulsion, two had medullary avulsion and the other four had laceration of the upper cervical spinal cord. Atlanto-occipital dislocation was observed in five cases, and a ring fracture around the foramen magnum in the other two cases. Intraventricular haemorrhage, probably due to tears of the choroid plexus caused by hyperextension or hyperflexion of the head, was found in seven cases. In just one of these seven cases, both of the lateral ventricles were filled with dark red haemocoagulum. Hyperextension is considered to occur more commonly in road trauma cases where the victim is alcoholically intoxicated.