Complete paraplegia following gunshot injury without direct trauma to the cord.

STUDY
DESIGN: A retrospective review of all patients with neurologic deficit following gunshot wounds that did not penetrate the spinal canal.
OBJECTIVES: To evaluate the possibility that neurologic deficit following gunshot wounds is possible without direct trauma to the cord. SUMMARY OF BACKGROUND DATA: Gunshot injuries to the spine account for 13% to 17% of all spinal cord injuries and are likely to result in complete paraplegia. Neurologic deficit is the result of direct trauma to the nervous tissue by the bullet, bone, or disc fragments, which compress the cord.
METHODS: The medical charts, radiographs, CT scans, and myelographies or MRIs of all patients admitted to our hospital with neurologic deficit secondary to gunshot wounds between 1977 and 2003 were reviewed. Twenty-six patients were identified: 15 with complete and 11 with incomplete paraplegia. In 19 patients, the spinal canal at the level of injury was explored and decompressed.
RESULTS: In 3 patients with complete paraplegia at the thoracic level, CT scan, myelography (1 patient), MRI (2 patients), and operative exploration (2 patients) did not indicate any signs of canal compromise. Two were injured by low-velocity bullets passing through the vertebra (in 1 patient) and the posterior part of the lamina (in the second). The third was injured by high-velocity bullets with no signs on MRI of any injury to the vertebral column or spinal cord. At follow-up 4.1 years later, on average, none had any neurologic recovery.
CONCLUSION: Neurologic deficit following gunshot wounds is possible even without violation of the spinal canal. It is most probably the result of the kinetic energy emitted by the bullet.