MAGNETIC-RESONANCE-IMAGING IN THE EVALUATION OF SPINAL-CORD INJURY WITHOUT RADIOGRAPHIC ABNORMALITY IN CHILDREN

SEVEN CHILDREN AGED birth to 17 years with spinal cord injury without radiographic abnormality (SCIWORA) were studied with magnetic resonance imaging (MRI) between 3 hours and 16 days after the injury. There were six cervical cord injuries and one thoracic cord injury. The MRI findings were divided into two groups: extraneural and neural. The extraneural findings included one case of anterior longitudinal ligament disruption and anterior C6-C7 disc herniation associated with hyperextension; one case of posterior longitudinal ligament disruption and C2-C3 disc herniation associated with lateral flexion; and one case of C6-C7 disc abnormality consistent with increased water content occurring with hyperflexion. These ligament and disc injuries did not correlate with late instability. The neural MRI findings included one case of cord transection with rostral cord stump hemorrhage and one case of hemorrhage involving the majority of the cord's transverse diameter, both associated with permanent complete cord injuries; one case of hemorrhage involving a minor portion of the cord and of the brain stem's transverse diameter associated with a severe partial cord injury but subsequent incomplete improvement; one case of edema without hemorrhage associated with Brown-Sequard syndrome and subsequent incomplete improvement; and three cases of normal cord signal and outline. Two of the latter patients had mild cord injuries that recovered completely. In the third, a child with complete T12 sensorimotor paralysis at presentation, the normal MRI findings predicted the subsequent complete recovery. No extraaxial compressive lesion was demonstrated in these seven children. The authors conclude that in SCIWORA, 1) the demonstration of ligament and disc injuries supports the hypothesis that the cord injury is secondary to sprain or partial tearing of stabilizing ligaments, allowing excessive intersegmental displacements; 2) these ligament and disc injuries are highly correlated with the mechanisms of injury, but not with the development of overt instability; 3) the MRI findings for the cord are highly correlated with the prognosis (cord transection and major hemorrhage with poor outcome; minor hemorrhage or ''edema only'' with moderate to good recovery; and absence of abnormal cord signal with complete recovery); and 4) MRI is not likely to alter the acute management of childhood SCIWORA except when progression of the initial deficits suggests extraaxial cord compression.