Arachnoiditis ossificans and syringomyelia: A unique presentation.

Background: Arachnoiditis ossificans (AO) is a rare disorder that was differentiated from leptomeningeal calcification by Kaufman and Dunsmore in 1971. It generally presents with progressive lower extremity myelopathy. Though the underlying etiology has yet to be fully described, it has been associated with various predisposing factors including vascular malformations, previous intradural surgery, myelograms, and adhesive arachnoiditis. Associated conditions include syringomyelia and arachnoid cyst. The preferred diagnostic method is noncontrast computed tomography (CT). Surgical intervention is still controversial and can include decompression and duroplasty or durotomy.

Case Description: The authors report the case of a 62-year-old male with a history of paraplegia who presented with a urinary tract infection and dysautonomia. His past surgical history was notable for a C4-C6 anterior fusion and an intrathecal phenol injection for spasticity. A magnetic resonance image (MR) also demonstrated a T6-conus syringx. At surgery, there was significant ossification of the arachnoid/dura, which was removed. After a drain was placed in the syrinx, there was a significant neurologic improvement.

Conclusion: This case demonstrates a unique presentation of AO and highlights the need for CT imaging when a noncommunicating syringx is identified. In addition, surgical decompression can achieve good results when AO is associated with concurrent compressive lesions.