Cervical spinal canal stenosis first presenting after spinal cord injury due to minor trauma: an insight into the value of preventive decompression

Abstract

INTRODUCTION: Patients with pre-existing cervical spinal canal stenosis (CSCS) may have minimal or no symptoms. However, performing preventive decompression is controversial as the incidence of CSCS leading to severe cord injury is unknown. Hence, this study aimed to revisit the threshold for surgery in “silent” CSCS by reviewing the neurologic outcomes of patients with undiagnosed CSCS who sustained a cervical spinal cord injury (CSCI). METHODS: Two groups of subjects were recruited for analysis, including those with trauma-induced CSCI without fracture or dislocation, and asymptomatic subjects recruited from the general population. Magnetic resonance imaging canal sizes were compared between groups. Within the patient group, neurological assessments and outcomes by Frankel grade were performed in patients treated surgically or conservatively. RESULTS: A total of 32 patients with CSCS were recruited. The mean (± standard deviation) spinal canal sagittal diameter of all cases was 5.3 ± 1.4 mm, versus 10.5 ± 1.7 mm for the asymptomatic group. Decompression was performed in 17 patients and conservative treatment in 15. Mean follow-up duration was 19.3 ± 17.0 months. At final follow-up, 3 (9.3%) patients returned to their pre-injury Frankel grade, whereas 26 (83.3%) patients lost one or more neurological grade. CONCLUSION: Majority of patients with “silent” CSCS who sustained cervical cord injuries did not return to their pre-injury neurological status. These subjects have pre-existing canal stenosis which was not observed in our control group. Given the poor neurological outcome of CSCS, a lower threshold for surgery may be indicated to avoid these disastrous injuries.