title: Subarachnoid, subdural and interdural spaces at the clival region: an anatomical study.
abstract: OBJECTIVE
  We aimed to show the significance of the anterior pontine membrane as a determining structure between the subdural and subarachnoid space in the clival region.
  
  
  METHODS
  Five adult cadaver heads and five cerebral hemispheres were used. The skull vault and hemipheres were removed by sectioning through the pontomesencephalic junction. Five other heads hemispheres were removed but the arachnoid membrane was protected and the cerebral side of the clival dura mater was dissected. In another specimen, the dural porus of the abducens nerve was sectioned for histological evaluation. Three cases of hematoma at the clivus were presented to support our findings.
  
  
  RESULTS
  The anterior pontine membrane is the arachnoid membrane forming the anterior wall of the prepontine cistern with its lateral extension at the skull base. This membrane forms the subdural and subarachnoid spaces by forming a barrier between the clival dura mater and neurovascular structures of the brainstem. There were rigid fibrous trabeculations between both cerebral and periosteal dural layers forming the basilar plexus as the interdural space in the clivus.
  
  
  CONCLUSIONS
  The anterior pontine membrane separates the subdural and subarachnoid spaces at the clival region. The hematomas of the clival region require to be evaluated with consideration given to the existance of the subdural space.
authors.affiliation: M.H. Ataturk Training and Research Hospital, 2nd Department of Neurosurgery, Ankara, Turkey. giyas67@hotmail.com
authors.forename: Giyas
authors.initials: G
authors.lastname: Ayberk
authors.forename: Mehmet Faik
authors.initials: MF
authors.lastname: Ozveren
authors.forename: Sevil
authors.initials: S
authors.lastname: Aslan
authors.forename: Mesut Emre
authors.initials: ME
authors.lastname: Yaman
authors.forename: Onur
authors.initials: O
authors.lastname: Yaman
authors.forename: Selim
authors.initials: S
authors.lastname: Kayaci
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Tekdemir
mesh_terms: D000010:Abducens Nerve / Q000473:pathology; D000058:Accidental Falls; D002102:Cadaver; D002648:Child; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D004388:Dura Mater / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D015600:Glasgow Coma Scale; D006408:Hematoma, Subdural / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008578:Meninges / Q000033:anatomy & histology; D008636:Mesencephalon / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008875:Middle Aged; D011149:Pons / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D019291:Skull Base / Q000033:anatomy & histology; D013345:Subarachnoid Hemorrhage / Q000473:pathology; D013346:Subarachnoid Space / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D013355:Subdural Space / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D014129:Trabecular Meshwork / Q000033:anatomy & histology / Q000000981:diagnostic imaging