PO:10:146 | Dorsal myelopathy in a patient with radiographic axial spondyloarthritis

Chiara Nobili¹, Siria Ripiccini¹, Marco Panetta¹, Elisabetta Greco¹, Barbara Kroegler¹, Paola Conigliaro¹, Alberto Bergamini¹, Maria Sole Chimenti¹ | ¹Università degli Studi di Roma-Tor Vergata, Italy

Background. Neurological involvements in axial spondyloarthritis (axSpA) are uncommon but can lead to serious complications. Among these, the occurrence of an epidural fluid–cellular collection is extremely rare and scarcely reported, representing a significant diagnostic challenge in differentiating infectious, neoplastic, and inflammatory etiologies. We describe the case of a patient with radiographic axSpA complicated by dorsal myelopathy secondary to an inflammatory epidural collection.

Materials and Methods. A 29-year-old man with a history of inflammatory back pain and family history of spondyloarthritis presented with worsening thoracolumbar pain, sphincter dysfunction, and progressive lower limb paraparesis. Laboratory investigations revealed elevated CRP (22.6 mg/L), HLA-B27 positivity, and a positive TB Quantiferon test. Contrast-enhanced spinal MRI demonstrated a large posterior epidural fluid–cellular collection extending from D4 to D6, causing spinal cord compression and signal alterations consistent with myelopathy. Bone marrow edema was also observed in the cervical, thoracic, and lumbar vertebrae, as well as in the sternal manubrium. Radiographic imaging showed syndesmophytes, bilateral sacroiliac ankylosis, and thoracolumbar Romanus lesions. The patient underwent neurosurgical decompression with laminectomy and paravertebral tissue biopsy.

Results: Histopathological analysis revealed compact and trabecular bone with preserved architecture, surrounded by fibro-adipose tissue showing inflammatory infiltrates occasionally organized into small B- and T-cell germinal-like centers, consistent with a reactive inflammatory process. Microbiological studies, including cultures and PCR for Mycobacterium tuberculosis, were negative. PET-CT did not reveal hypermetabolic foci suggestive of lymphoproliferative disease. Given the high disease activity (ASDAS-CRP 4.76; BASDAI 7.4), HLA-B27 positivity, and characteristic radiological features of axSpA, an inflammatory etiology for the epidural collection was strongly supported.

Conclusions. We report an atypical complication of radiographic axial spondyloarthritis presenting as dorsal myelopathy due to an inflammatory epidural collection. To our knowledge, similar cases have not been previously described. Early recognition and multidisciplinary management are essential to ensure appropriate diagnosis and treatment.