title: The anatomy of the inferior petrosal sinus, glossopharyngeal nerve, vagus nerve, and accessory nerve in the jugular foramen.
abstract: OBJECTIVE
  To define the variations of the courses of the cranial nerves and the inferior petrosal sinuses as they enter and traverse the jugular foramen.
  
  
  METHODS
  Thirty-nine cadaveric specimens containing the jugular foramen were scanned with 1-mm contiguous axial and coronal CT sections. Each specimen was dissected to evaluate the position of the cranial nerves and inferior petrosal sinus as they entered the jugular foramen.
  
  
  RESULTS
  The glossopharyngeal nerve entered the most superior, anterior, and medial aspect of the jugular foramen and descended in the anterior portion of the jugular foramen, often within a groove. The vagus and accessory nerves could not be separated by CT. They entered the jugular foramen most often anterior or anterior and inferior to the jugular spine of the temporal bone and descended in a position ranging from medial to anterior to the jugular vein. The inferior petrosal sinus most often coursed inferior to the horizontal portion of the glossopharyngeal nerve and entered the jugular system in the jugular foramen, at the exocranial opening or below the skull base. A pars nervosa and pars venosa could be identified only at the endocranial opening, where the jugular spine separated the pars nervosa containing the inferior petrosal sinus and three cranial nerves from the pars venosa containing the jugular vein.
  
  
  CONCLUSIONS
  Our evaluation demonstrated anatomic variation in the area of the jugular foramen.
authors.affiliation: Department of Radiology, University of Colorado Health Sciences Center, Denver 80262.
authors.forename: D
authors.initials: D
authors.lastname: Rubinstein
authors.forename: B S
authors.initials: BS
authors.lastname: Burton
authors.forename: A L
authors.initials: AL
authors.lastname: Walker
mesh_terms: D000055:Accessory Nerve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003392:Cranial Sinuses / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D004210:Dissection; D005930:Glossopharyngeal Nerve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006801:Humans; D007601:Jugular Veins / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D009777:Occipital Bone / Q000000981:diagnostic imaging / Q000294:innervation*; D010579:Petrous Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012886:Skull / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000294:innervation; D013701:Temporal Bone / Q000000981:diagnostic imaging / Q000294:innervation*; D014057:Tomography, X-Ray Computed; D014630:Vagus Nerve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging