Mean PFV values were found to be smaller in pediatric CMI patients than control patients; this complements earlier studies in adults and supports the present theory concerning the pathophysiological mechanism of CMI. Subtle morphometric differences among asymptomatic and symptomatic patients aged 0-9 years stress the importance of monitoring asymptomatic patients for the onset of symptoms in their adult years. Symptom development in CMI is likely multifactorial and is much more extensive than the degree of cerebellar tonsillar herniation.

Background: Spinal cord injury without radiographic abnormality (SCIWORA) represents a traumatic myelopathy, either transient or permanent, that is not associated with visible vertebral fractures or ligamentous abnormalities on plain radiographs or CT. MRI has become essential in the diagnosis and evaluation of trauma patients and in predicting the long-term neurological outcome. Methods: The medical charts of 578 children with vertebral trauma at the Children’s Hospital of Eastern Ontario and the Hospital for Sick Children were retrospectively reviewed. Results: Forty-five patients were identified as having traumatic myelopathy. Three of these patients had SCIWORA. Two sustained thoracic spinal cord injuries as a result of motor vehicle accidents and permanent neurological deficits. The third was involved in a sports-related injury and sustained a cervical spine injury that improved in 48 h. Conclusions: SCIWORA is uncommon. The serious neurological sequelae that can result from a missed diagnosis merit more attention in identifying a spinal lesion in children with traumatic myelopathy. MRI has played a valuable role in this respect and may be even more predictive of outcome than the presenting neurological findings. The SCIWORA acronym can be modified to SCIWONA (spinal cord injury without neuroimaging abnormality) in order to highlight the importance of MRI in the prognosis.