title: [Topographic anatomy of the asterion].
abstract: BACKGROUND
  In the surgical approaches to the posterior fossa, the accurate location of the transverse-sigmoid sinus (TS-SS) complex is of great importance. The asterion is a referral landmark to the transverse sinus location.
  
  
  METHODS
  Twenty-five skulls of adult cadavers were studied. We seek for the relationships of the asterion with: TS location, mastoid emissary vein, suprametal crest and inion.
  
  
  RESULTS
  The asterion was found in 49 cases. In the great majority of cases (87.8%) the asterion was over the TS (72.2% over the sinus proper, 27.8% over the TS-SS transition). The mastoid emissary vein was present in 46 cases, and in 36% we found two veins.
  
  
  CONCLUSIONS
  The burr hole for posterolateral approaches to the posterior fossa must be located below and behind the asterion.
authors.affiliation: Facultad de Medicina y Hospital de Clínicas Dr. Manuel Quintela. Montevideo. Uruguay.
authors.forename: F
authors.initials: F
authors.lastname: Martinez
authors.forename: A
authors.initials: A
authors.lastname: Laxague
authors.forename: L
authors.initials: L
authors.lastname: Vida
authors.forename: H
authors.initials: H
authors.lastname: Prinzo
authors.forename: N
authors.initials: N
authors.lastname: Sgarbi
authors.forename: V R
authors.initials: VR
authors.lastname: Soria
authors.forename: C
authors.initials: C
authors.lastname: Bianchi
mesh_terms: D000328:Adult; D002102:Cadaver; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology* / Q000601:surgery; D003392:Cranial Sinuses / Q000033:anatomy & histology*; D006801:Humans; D019635:Neurosurgical Procedures; D012886:Skull / Q000033:anatomy & histology; D013499:Surface Properties