Secondary medulla oblongata involvement following middle cervical spinal cord injury associated with latent traumatic instability in a patient with ossification of the posterior longitudinal ligament.

STUDY
DESIGN: A case report.
OBJECTIVES: To report a rare case of extension of edema and hemorrhage from initial C4-5 spinal injury to the medulla oblongata.
SETTING: Center for Spinal Disorders and Injuries, Bibai Rosai Hospital, Japan.
METHODS: A 68-year-old man with ossification of the posterior longitudinal ligament (OPLL) had sustained tetraplegia after tumbling over a stone. Initially, the patient was diagnosed with an acute C4-5 spinal cord injury without radiological abnormalities and was treated conservatively. At 7 h after the injury, the patient had an ascending neurological deficit, which required respiratory assistance. Magnetic resonance imaging revealed a marked swelling of the spinal cord above C4-5 extending to the medulla oblongata.
RESULTS: Retrospective radiological assessment revealed that the spine was unstable at the injury level because of discontinuities in both anterior and posterior longitudinal ligaments. There was also signal intensity change within the retropharyngeal space at the C4-5 intervertebral disc. This injured segment was highly vulnerable to post-injury dynamic stenosis and easily sustained secondary neural damage.
CONCLUSIONS: This case report emphasizes a careful radiological assessment of latent structural instability in patients with OPLL in order to detect and prevent deteriorative change in the spinal cord.