Study design: This is a prospective imaging study of adult patients with cervical spinal cord injury without radiographic abnormality (SCIWORA).
Objective: The purpose of this study was to investigate the occurrence rate of intramedullary high-signal intensity (increased signal intensity [ISI]) and prevertebral hyperintensity (PVH) in patients with SCIWORA, and examine their relationship to symptom severity and surgical outcome.
Summary of background data: SCIWORA is accompanied by the presence of neurologic symptoms in the absence of positive radiographic findings before the emergence of magnetic resonance imaging (MRI). There are few reports regarding the image features on MRI in these patients.
Methods: One-hundred consecutive patients with SCIWORA who had undergone expansive laminoplasty were enrolled. There were 79 men and 21 women; the mean age was 55 years (range, 16-87 years). All patients underwent functional x-ray and MRI in the acute phase. On MR T2-weighted imaging sagittal view, occurrence of ISI and PVH was evaluated. Range of ISI and PVH was measured relative to C3 vertebral height. Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy (JOA score), it's recovery rate, and ASIA impairment scale were used to evaluate neurological status.
Results: ISI was observed in 92 patients and PVH in 90 patients on MRI preoperatively. The range of ISI and PVH tended to increase with scores on the preoperative ASIA scale. ISI and PVH were seen in all patients with ASIA A and B. There was a significant negative correlation between the range of ISI and preoperative JOA score. A significant negative correlation between the range of ISI and recovery rate of JOA score was also seen.
Conclusion: ISI and PVH occurred in more than 90% of patients with SCIWORA. The range of ISI significantly reflected symptom severity and prognosis for neurologic outcome.