Erosive Cervico-occipital Arthritis Caused by Enthesitis in a Patient with Axial Spondylathritis

Abstract: The occipito-cervical junction may be affected during the course of spondyloarthritis (SpA). However it is not usual be an inaugural manifestation of SpA. We report herein a case of axial SA in a young patient discovered by O-C1 arthritis.

Case Report: A 29 years-old man with no particular past medical history of trauma, psoriasis, tumor, inflammatory bowel disease, eye redness or inflammatory rheumatic disease in family complained about persistent discomfort of the upper cervical spine for 2 years. Physical examination revealed a limited range of motion in rotation of the cervical spine with no other abnormalities. X-rays of the cervical spine and of the cranio-cervical hinge were unremarkable. MRI showed a low signal intensity on T1-weighted imaging around lateral facets of O-C1 joints and high signal intensity on STIR sequences. Searching for etiology, plain radiography of the pelvis revealed sarco-iliitis grade IV of New York's criteria and the patient was also positive for HLA B27. The diagnosis of axial SpA was retained.

Conclusion: This is the second case of SpA revealed by O-C1 arthritis. As the craniocervical junction is not well analyzed in X-rays, persistent upper cervical pain should be investigated by MRI. Diagnosis of SpA should be considered and discovering of O-C1 arthritis should lead to performance of a pelvis X-rays.