title: Cervicomedullary compression secondary to massive calcium pyrophosphate crystal deposition in the atlantoaxial joint with intradural extension and vertebral artery encasement.
abstract: BACKGROUND
  Deposition of CPPD crystals occurs in the fibrous and hyaline cartilage of the joints and intervertebral disks of the spine. Half of patients known to have chondrocalcinosis had asymptomatic calcification in the odontoid region. The cases of 12 patients with a spinal cord syndrome secondary to CPPD deposition in the odontoid region were published in the literature. In all those cases, the mass lesion was extradural in location with good outcome after surgical decompression via the transoral route.
  
  
  METHODS
  We report on a rare case of large periodontoid CPPD deposition causing cervicomedullary compression, erosion of the overlying bone, and underlying dura with intradural extension and vertebral artery encasement.
  
  
  CONCLUSIONS
  Calcium pyrophosphate dihydrate is a rare cause of cervicomedullary compression. Intradural extension of periodontoid CPPD has not been reported on.
authors.affiliation: Department of Neuroradiology, Neurosciences Center, All India Institute of Medical Sciences, New Delhi 110029, India.
authors.forename: Kanika S
authors.initials: KS
authors.lastname: Sethi
authors.forename: Ajay
authors.initials: A
authors.lastname: Garg
authors.forename: Mehar C
authors.initials: MC
authors.lastname: Sharma
authors.forename: Faiz U
authors.initials: FU
authors.lastname: Ahmad
authors.forename: Bhawani S
authors.initials: BS
authors.lastname: Sharma
mesh_terms: D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D002805:Chondrocalcinosis / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D003388:Cranial Fossa, Posterior / Q000473:pathology / Q000503:physiopathology; D019299:Decompression, Surgical; D004388:Dura Mater / Q000473:pathology / Q000503:physiopathology; D017809:Fatal Outcome; D005539:Foramen Magnum / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008526:Medulla Oblongata / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D008875:Middle Aged; D019635:Neurosurgical Procedures; D013117:Spinal Cord Compression / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D025241:Spondylarthritis / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed; D014715:Vertebrobasilar Insufficiency / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*