Arachnoiditis ossificans

Objective: Arachnoiditis ossificans is an uncommon clinical entity in which arachnoid ossification leads to clinical symptomatology. In this case report, we describe the case of a myelopathic patient with arachnoid ossifications, an arachnoid cyst, and syringomyelia coexisting with a herniated thoracic disc at the same levels. Case Description: An 81-year-old woman presented with rapidly progressive leg weakness, dysesthetic pains, and urinary incontinence. Results: The patient underwent thoracic laminectomy with costotransversectomy for resection of ossified arachnoid and re-establishment of cerebrospinal fluid pathways. Conclusion: Altered cerebrospinal fluid dynamics secondary to the obstruction in subarachnoid flow may predispose to the formation of an arachnoid cyst, and the cyst itself may be the proximate cause of the myelopathy.