437 The Leptomeninges as a New and Critical Organ: 1st ScR of "Arachnoiditis, " With 62 Other Names for the Same Pathology. (1st April 2022)

• Record Type: Journal Article
• Authors: Wottrich, Stephanie; Palackdharry, Carol; Witiw, Christopher D.; Dienes, Erin; Bydon, Mohamad; Steinmetz, Michael P.; Traynelis, Vincent C.
• Is Part Of: Neurosurgery. Volume 68(2022)Supplement 1
• Page Start: 104
• Page End: 104
• Publication Date: 2022-04-01
• Subjects: Nervous system -- Surgery -- Periodicals; 617.48005
• DOI: 10.1227/NEU.0000000000001880_437
• Languages: English
• ISSNs: 0148-396X

Abstract

Abstract : INTRODUCTION: The goal of this prospective PRISMA-based Systematic Scoping Review with modified e-Delphi [ScR] is to synthesize all available information about a reportedly iatrogenic disease typically called "arachnoiditis" [arcs]. Past literature describes a rare, iatrogenic disease of the arachnoid membrane, with no known treatment. By 2021, nothing materially new had been added to the literature. The present ScR aims to clarify the clinical view of arcs. Grey data from legal documents, government proceedings, government and manufacturer device adverse events [AE] tracking, and investigative reporting was included. Although excluded from the data charting, we were surprised by multiple articles about the biology of the subarachnoid space [SAS] and the critical role it plays in protecting and maintaining the central nervous system [CNS]. METHODS: The entire ScR is published at https://arcsology.org/about-arcsology/scoping-systematic-review-of-arachnoiditis-official-protocol/ . Data charting was standardized through an iterative process involving = 2 independent clinicians. Data synthesis was performed in R. RESULTS: A total of 46, 646 sources were screened. Data from 887 sources are synthesized, finding 63 names used for pathology of the leptomeninges [LM]. "Arachnoiditis" is a misnomer. Leptomeningeal diseases are not rare and can cause a range of neurologic symptoms. Spinal versus brain presentations are similar, although the two categories differ substantially. Many causes were identified. In high-income countries, >50% of cases are caused by non-communicable diseases, with spinal surgery as the largest single contributor. In underdeveloped countries, communicable diseases and trauma predominate. In sum: irritants in or around the LM can trigger an inflammatory and/or fibrotic cascade within the subarachnoid space. Prognosis is variable and continuous progression does not occur in most patients. CONCLUSION: These results impact all health care practitioners. Consistent and correct terminology is critical going forward. The WHO-ICD11 team is currently reviewing our proposal for name and hierarchical changes. The LM meet criteria for a newly recognized organ with a unique and critical structure, function, and cellular components. Integration of in vitro and animal models will be helpful for future directions.