title: Arachnoiditis ossificans associated with syringomyelia: An unusual cause of myelopathy.
abstract: OBJECTIVE
  The pathophysiology of arachnoiditis ossificans (AO) and its association with syringomyelia remains a rare and poorly understood phenomenon. Here, we present a case of AO associated with syringomyelia, a review of literature, and a discussion of current understanding of disease pathophysiology.
  
  
  METHODS
  A literature review was performed using MEDLINE (January 1900-May 2010) and Embase (January 1900-May 2010) to identify all English-language studies that described AO with syringomyelia. The current report was added to published cases.
  
  
  RESULTS
  Over 50 cases of AO are reported in literature, of which only eight are associated with syringomyelia. The various presumptive etiologies of syrinx formation include abnormalities in blood circulation, ischemia, hydrodynamic alternations in cerebrospinal fluid (CSF) flow, tissue damage, or incidental coexistence. Changing CSF dynamics related to decreased compliance of the subarachnoid space and subsequent paracentral dissection of the spinal cord may be implicated in the disease process. magnetic resonance imaging (MRI) scanning may identify the syrinx but fail to diagnose the calcified arachnoid. Five patients, including the current case, improved clinically following laminectomy and decompression.
  
  
  CONCLUSIONS
  Syringomyelia in association in AO is a rare phenomenon. A high index of suspicion is required and both MRI and computed tomography (CT) are recommended for diagnosis. The pathophysiology of syringomyelia in AO remains an area of ongoing research.
authors: Division of Neurosurgery and Spinal Program, Krembil Neuroscience Center, Toronto Western Hospital, University of Toronto, Ontario, Canada.
authors: George M
authors: GM
authors: Ibrahim
authors: Tara
authors: T
authors: Kamali-Nejad
authors: Michael G
authors: MG
authors: Fehlings
references: J Clin Neurosci. 2000 Jan;7(1):66-8
references: 10847657
references: Neurology. 1971 Dec;21(12):1243-8
references: 5002424
references: J Neurosurg. 2002 Sep;97(2 Suppl):239-43
references: 12296687
references: Neurology. 1990 Apr;40(4):714-6
references: 2320252
references: J Neurosurg. 1999 Oct;91(2 Suppl):223-9
references: 10505510
references: J Neurosurg. 1995 May;82(5):802-12
references: 7714606
references: Clin Imaging. 1999 Jan-Feb;23(1):1-4
references: 10332589
references: J Neurosurg. 1975 Feb;42(2):222-5
references: 803555
references: J Neurosurg. 1999 Oct;91(4):553-62
references: 10507374
references: J Neurosurg. 2001 Jan;94(1 Suppl):115-20
references: 11147844
references: J Clin Neurosci. 2007 Jun;14(6):572-6
references: 17368029
references: Neurosurgery. 2004 Oct;55(4):985
references: 15934184