Arachnoiditis Ossifications in the Spine

Abstract

Introduction: Arachnoiditis ossificans (AO) in the spine is a rare entity characterized by progressive calcification of the arachnoid and dural sac, with consequent neurological involvement. Objective: Review the causes, clinical manifestations, and complementary studies for their correct diagnosis. Method: Systematic review under PRISMA guidelines, with search in Pubmed, Lilacs, and Embase. Patient demographics (sex and age), history reported as a cause of AO and time elapsed between cause and diagnosis of AO, clinical manifestations, and complementary studies used for diagnosis were collected. Results: 38 articles, of which we collected 46 patients (25 women, 21 men), mean age of 52 years. The most frequent cause was previous spine surgery and myelography with fat-soluble contrast. The most frequent symptoms were insufficient muscle strength (74%) and pain (69%). CT was used in 76%. The most frequent location was thoracic (35%). Conclusion: Its pathogenesis is unclear; described as the final cause of a chronic inflammatory process in the arachnoid with the consequent bone metaplasia. Diagnosis usually precedes a long period of pain and progressive neurological symptoms. The most sensitive and specific complementary study for the diagnosis is the tomography without contrast, which should be requested in case of clinical suspicion. Level of Evidence II; Systematic Review.