title: The early and late stages of crowned dens syndrome: two case reports.
abstract: BACKGROUND
  Crowned dens syndrome (CDS) is a rare form of calcium phosphate crystal depositions and often presents with recurrent neck pain, stiffness of neck, increased erythrocyte sedimentation rate, and episodes of fever.
  
  
  OBJECTIVE
  The goal of this report is to identify the early and late stages of CDS and its consequences as the result of repeated attacks of CDS at cervical spine in its late stage.
  
  
  METHODS
  This is a case report.
  
  
  METHODS
  We reported one case of early-stage CDS and one late-stage CDS.
  
  
  RESULTS
  The two patients shared some common clinical features of acute attack of CDS, such as increased erythrocyte sedimentation rate, C-reactive protein, episode of fever, and increased white blood cells along with high blood glucose levels. The first case showed early phase of CDS with computed tomography (CT) scan that only showed mild calcification around the dens. The second case had appearance of late stage of CDS with more severe chronic degenerative changes of cervical spine.
  
  
  CONCLUSIONS
  Early stage of CDS can be difficult to identify because of mild clinical symptoms, but CT scan is a preferable method to demonstrate densities surrounding the top and sides of the odontoid process. In the late stage of CDS, radiolographic features often include diffuse periodontoid calcifications, diffuse destructive discopathies, and apophyseal joint destruction, and patient might have severe neurological symptoms.
authors.affiliation: Department of Spine Surgery, The Third Affiliated Hospital of Nanfang University, 183 Zhangshandadaoxi Rd, Guangzhou 510600, China. Electronic address: zhhaohk@yahoo.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Spine Surgery, The Third Affiliated Hospital of Nanfang University, 183 Zhangshandadaoxi Rd, Guangzhou 510600, China; Guangdong Orthopedic Institute, 183 Zhangshandadaoxi Rd, Guangzhou 510600, China.
authors.forename: Dadi
authors.initials: D
authors.lastname: Jin
authors.affiliation: Department of Rheumatology, The Third Affiliated Hospital of Nanfang University, 183 Zhangshandadaoxi Rd, Guangzhou 510600, China.
authors.forename: Erwei
authors.initials: E
authors.lastname: Sun
mesh_terms: D000369:Aged, 80 and over; D002114:Calcinosis / Q000000981:diagnostic imaging*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D013577:Syndrome
keywords: Arthropathy; Calcium phosphate crystal depositions (CPPD); Cervical spine; Crowned dens syndrome; Neck pain; Pseudogout