Usefulness of cervical computed tomography and magnetic resonance imaging for rapid diagnosis of crowned dens syndrome: A case report and review of the literature.

INTRODUCTION: Crowned dens syndrome is a rare disease entity which radiologically shows calcification of the cruciform ligament around the odontoid process. We report a patient with crowned dens syndrome who improved dramatically in 5days following treatment with oral nonsteroidal anti-inflammatory medication.

PRESENTATION OF CASE: A 61-year-old man was admitted to our hospital with a severe occipital headache and sudden onset of neck stiffness. Neurological examination on admission revealed a high fever and cervical rigidity. Laboratory examination revealed a markedly elevated white blood cell count and C-reactive protein level, but cerebrospinal fluid studies revealed only a slight abnormality. A cervical computed tomography scan and its three-dimensional reconstruction detected a remarkable crown-like calcification surrounding the odontoid process. Cervical magnetic resonance imaging did not demonstrate strong direct compression of the cervical cord; however, the soft tissue surrounding the odontoid process was hyperintense on T2-weighted imaging with fat suppression. Based on the radiological findings, the patient was diagnosed with crowned dens syndrome and was immediately treated with non-steroidal anti-inflammatory drugs. The patient's condition drastically improved within 5days.

DISCUSSION: It was very interesting that the soft tissue surrounding the odontoid process was hyperintense on magnetic resonance T2-weighted imaging with fat suppression, and the signal change disappeared 2 weeks after the administration of oral non-steroidal anti-inflammatory drugs. We think that magnetic resonance imaging is useful for proving inflammation in patients with crowned dens syndrome.

CONCLUSION: This is the first report making reference to the magnetic resonance imaging findings of crowned dens syndrome.