Magnetic Resonance Imaging in the Evaluation of Spinal Cord Injury without Radiographic Abnormality in Children:

Prevalence of cervical spine injury in infants with head trauma

OBJECT

The incidence, type, and severity of pediatric cervical spine injuries (CSIs) are related to age and mechanism of injury. In this study, the authors assessed the prevalence of CSIs in infants with head trauma treated in their institution.

METHODS

The authors reviewed the medical records of children younger than 1 year of age who presented to The Children's Hospital with head injuries between January 1993 and December 2007. They excluded infants with head injuries resulting from motor vehicle accidents and known falls from heights greater than 10 ft. For each patient, collected data included age, cause of injury, diagnosis, discharge disposition, and outcome. Relevant imaging data were reviewed, and when appropriate, autopsy reports were also reviewed.

RESULTS

Nine hundred five infants with head trauma and without a major mechanism/cause were identified. Their mean age was 4.3 months. Of the 905 patients, only 2 cases of CSI were detected, giving a prevalence of 0.2%. The mechanism of injury in these 2 patients was nonaccidental trauma (NAT).

CONCLUSIONS

The study revealed a very low prevalence of CSIs in infants with head trauma (0.2%). Routine cervical spine imaging in these infants, therefore, appears to have low diagnostic yield. The mechanism of head injury was NAT in the 2 patients who sustained an associated CSI. This supports the need for more stringent cervical spine imaging criteria for the infant with suspected NAT.

Neck injuries in young pediatric homicide victims

OBJECT

In this study, the authors estimate the prevalence of injuries to the soft tissue of the neck, cervical vertebrae, and cervical spinal cord among victims of abusive head trauma to better understand these injuries and their relationship to other pathophysiological findings commonly found in children with fatal abusive head trauma.

METHODS

The population included all homicide victims 2 years of age and younger from the city of Philadelphia, Pennyslvania, who underwent a comprehensive postmortem examination at the Office of the Medical Examiner between 1995 and 2003. A retrospective review of all available postmortem records was performed, and data regarding numerous pathological findings, as well as the patient's clinical history and demographic information, were abstracted. Data were described using means and standard deviations for continuous variables, and frequency and ranges for categorical variables. Chi-square analyses were used to test for the association of neck injuries with different types of brain injury.

RESULTS

The sample included 52 children, 41 (79%) of whom died of abusive head trauma. Of these, 29 (71%) had primary cervical cord injuries: in 21 there were parenchymal injuries, in 24 meningeal hemorrhages, and in 16, nerve root avulsion/dorsal root ganglion hemorrhage were evident. Six children with abusive head trauma had no evidence of an impact to the head, and all 6 had primary cervical spinal cord injury (SCI). No child had a spinal fracture. Six of 29 children (21%) with primary cervical SCIs had soft-tissue (ligamentous or muscular) injuries to the neck, and 14 (48%) had brainstem injuries. There was a significant association of primary cervical SCI with cerebral edema (p = 0.036) but not with hypoxia-ischemia, infarction, or herniation.

CONCLUSIONS

Cervical SCI is a frequent but not universal finding in young children with fatal abusive head trauma. In the present study, parenchymal and/or root injury usually occurred without evidence of muscular or ligamentous damage, or of bone dislocation or fracture. Moreover, associated brainstem injuries were not always seen. Although there was a significant association of primary cervical cord injury with cerebral edema, there was no direct relationship to brainstem herniation, hypoxia-ischemia, or infarction. This suggests that cervical spinal trauma is only 1 factor in the pathogenesis of these lesions.

Cervical spine injuries in pediatric athletes: mechanisms and management

✓Sports-related injuries to the spine, although relatively rare compared with head injuries, contribute to significant morbidity and mortality in children. The reported incidence of traumatic cervical spine injury in pediatric athletes varies, and most studies are limited because of the low prevalence of injury. The anatomical and biomechanical differences between the immature spine of pediatric patients and the mature spine of adults that make pediatric patients more susceptible to injury include a greater mobility of the spine due to ligamentous laxity, shallow angulations of facet joints, immature development of neck musculature, and incomplete ossification of the vertebrae. As a result of these differences, 60 to 80% of all pediatric vertebral injuries occur in the cervical region. Understanding pediatric injury biomechanics in the cervical spine is important to the neurosurgeon, because coaches, parents, and athletes who place themselves in positions known to be associated with spinal cord injury (SCI) run a higher risk of such injury and paralysis. The mechanisms of SCI can be broadly subclassified into five types: axial loading, dislocation, lateral bending, rotation, and hyperflexion/hyperextension, although severe injuries often result from a combination of more than one of these subtypes. The aim of this review was to detail the characteristics and management of pediatric cervical spine injury.

Applications of diffusion-weighted MRI in thoracic spinal cord injury without radiographic abnormality

Diffusion-weighted MRI (DWI) has been proposed as a method to evaluate the integrity of white matter tracts in the spinal cord. The integrity of the spinal cord reflects the exact stage of traumatic injury. The purpose of this study was to evaluate the diagnostic value of DWI in SCIWORA in the thoracic spine. A total of five patients with thoracic SCIWORA underwent MRI and DWI within 48 h of injury. DWIs were obtained with a single-shot fast spin-echo (SSFSE) sequence; TI- and T2-weighted images were obtained with spin echo. Consistency among the clinical presentation, outcome, MRI and DWI was analysed. There was complete injury in one patient and partial in four patients. Four patients showed hypointense T1-weighted signal and hyperintense T2-weighted signal, and one patient had no changes on MRI. All patients showed hyperintense signal on DWI. Two patients made good recoveries (ASIA grades D and E), one had a moderate recovery (ASIA grade C), and two showed minimal or no improvement (ASIA grade A or B) in neurological function. Patients with no cord changes on MRI showed abnormal signals on DWI. It is likely that in the future DWI may provide important information complimentary to conventional MRI and allow a better prognostic evaluation of recovery from SCIWORA.

Cervical spine trauma in children: a review

Injuries of the cervical spine are relatively rare in children but are a distinct clinical entity compared with those found in adults. The unique biomechanics of the pediatric cervical spine lead to a different distribution of injuries and distinct radiographic features. Children younger than 9 years of age usually have upper cervical injuries, whereas older children, whose biomechanics more closely resemble those of adults, are prone to lower cervical injuries. Pediatric cervical injuries are more frequently ligamentous in nature, and children are also more prone to spinal cord injury without radiographic abnormality than adults are. Physical injuries are specific only to children. Radiographically benign findings, such as pseudosubluxation and synchondrosis, can be mistaken for traumatic injuries. External immobilization with a halo brace can be difficult and is associated with a high complication rate because of the thin calvaria in children. Surgical options have improved with the development of instrumentation specifically for children, but special considerations exist, such as the small size and growth potential of the pediatric spine.