title: Developmental abnormalities of the craniocervical junction resulting in Collet-Sicard syndrome.
abstract: Collet-Sicard syndrome describes the paralysis of cranial nerves IX-XII and is the most frequently reported neurologic complication associated with Jefferson fractures. As the lateral mass of the atlas is displaced laterally toward the styloid process and the stylohyoid ligament, the lateral mass impinges on cranial nerves IX-XII. However, Collet-Sicard syndrome in association with other anomalies of the atlas has rarely been reported.
  
  
  
  The aim of this study was to report an unusual case of Collet-Sicard syndrome as a result of developmental abnormalities of the craniocervical junction.
  
  
  
  This is a case report of a single patient.
  
  
  
  Chart and radiographic data were reviewed and reported.
  
  
  
  We report a 70-year-old man who developed hoarseness, dysarthria, and dysphagia from developmental abnormalities of the craniocervical junction including a congenital occiput-C1-C3 fusion and hypoplastic dens. On computed tomography, the distance between the left transverse process of the atlas and the left styloid process of the skull was 3 mm.
  
  
  
  In suspected Collet-Sicard syndrome, developmental abnormalities of the craniocervical junction should be considered in the differential diagnosis.
authors.affiliation: Department of Neurology, Eulji General Hospital, Eulji University, 68 Hangeulbiseok-ro, Nowon-gu, Seoul 01830, Republic of Korea. Electronic address: cobnut1@gmail.com.
authors.forename: Kyusik
authors.initials: K
authors.lastname: Kang
authors.affiliation: Department of Neurosurgery, Eulji General Hospital, Eulji University, 68 Hangeulbiseok-ro, Nowon-gu, Seoul 01830, Republic of Korea.
authors.forename: Byung Gwan
authors.initials: BG
authors.lastname: Moon
mesh_terms: D000368:Aged; D001270:Cervical Atlas / Q000002:abnormalities*; D019465:Craniofacial Abnormalities / Q000150:complications / Q000000981:diagnostic imaging*; D020435:Glossopharyngeal Nerve Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D020437:Hypoglossal Nerve Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D013577:Syndrome; D014057:Tomography, X-Ray Computed
keywords: Assimilation of the atlas; Collet-Sicard syndrome; Cranial neuropathy; Craniocervical junction; Developmental disorders; Hypoplastic dens