title: Cervical myelopathy by C1 posterior tubercle impingement in a patient with DISH.
abstract: METHODS
  A unique case of a patient with diffuse idiopathic skeletal hyperostosis (DISH) associated with C1 posterior tubercle impingement resulting in spinal canal stenosis and cervical myelopathy.
  
  
  OBJECTIVE
  To describe an uncommon mechanism of spinal cord compression in patient with DISH.
  
  
  BACKGROUND
  The neurologic deficits due to cervical DISH are relatively rare and a few cases of cervical spinal cord compression due to atlantoaxial subluxation, odontoid fracture, pseudotumor, ligamentous hypertrophy, and basilar impression have been reported. To the best of our knowledge, there has been no other report of a patient with DISH causing C1 posterior tubercle impingement and cervical myelopathy.
  
  
  METHODS
  A 75-year-old Japanese man, first diagnosed as hyperostosis of anterior and posterior longitudinal ligament 25 years ago, presented with gradual progression of numbness in both lower extremities, disturbed precise hand motion and urinary function. DISH, OPLL, and C1 posterior tubercle impingement was diagnosed by radiograph, CT, and MRI. Hyperintense signal in the C1 spinal cord on T2 weighted sequence was observed.
  
  
  RESULTS
  Laminectomy from C1-C3 was performed. Myelocompression and myelopathy improved after the surgical intervention. Multilevel fusion of the subaxial cervical spine and increase of the mechanical stress on the craniocervical segment may leads to partial damage of the ligaments and resulted in C1 posterior arch impingement.
  
  
  CONCLUSIONS
  This is the first report of unique C1 posterior tubercle impingement and myelopathy caused by DISH. We should keep it in mind that DISH can cause serious problems in the upper cervical spine even after 25 years of interval.
authors.affiliation: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan. masahitokawabori@yahoo.co.jp.ca
authors.forename: Masahito
authors.initials: M
authors.lastname: Kawabori
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Hida
authors.forename: Minoru
authors.initials: M
authors.lastname: Akino
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yano
authors.forename: Hisatoshi
authors.initials: H
authors.lastname: Saito
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Iwasaki
mesh_terms: D000368:Aged; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D019299:Decompression, Surgical; D018450:Disease Progression; D006801:Humans; D004057:Hyperostosis, Diffuse Idiopathic Skeletal / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D007796:Laminectomy; D008279:Magnetic Resonance Imaging; D008297:Male; D017887:Ossification of Posterior Longitudinal Ligament / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D013117:Spinal Cord Compression / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D013118:Spinal Cord Diseases / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D013130:Spinal Stenosis / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome