Thoracic myelopathy due to ossification of the posterior longitudinal ligament shown on dynamic MR

BACKGROUND: Magnetic resonance (MR) and computed tomography (CT) studies combined are the optimal studies for diagnosing thoracic ossification of the posterior longitudinal ligament (OPLL) contributing to myelopathy. Here, we report a 71-year-old female, whose additional dynamic thoracic MR demonstrated transient T6–T9 anterior OPLL with cord compression. CASE DESCRIPTION: A 71-year-old female presented with a progressive myelopathy originally attributed to cervical cord compression resulting in a cervical laminoplasty. However, when she failed to improve postoperatively, a dynamic thoracic MR was performed. On the flexion study, it demonstrated significant although transient T6–T9 anterior thoracic cord compression due to both OPLL and kyphosis. The patient’s symptoms resolved following a posterior thoracic fusion alone (i.e., no decompression was warranted). CONCLUSION: Dynamic MR studies (i.e., flexion studies) in addition to the routine MR and CT evaluations should be performed for patients with myelopathy attributed to thoracic OPLL/kyphosis.