Prepontine cistern

The prepontine cistern is an unpaired cistern located ventral to the pons and dorsal to the clivus.

Relationships:

• Anteriorly: clivus

• Posteriorly: the pons and basilar artery in its sulcus

• Superiorly (roof of the cistern): mesencephalic membrane of liliequist

• Inferiorly (floor of the cistern): the medial pontomedullary membrane, a thickened membrane (where the vertebral arteries join at the basilar point, approximately at the pontomedullaris junction) separating this cistern from the premedullary cistern

• Laterally: cerebellopontine cisterns

Contents: basilar artery and some of its branches (pontine perforators, origine of antero-inferior cerebellar artery), transverse pontine veins. Some authors include the abducens nerve (CN VI) in this cistern, but it's preferable to consider that the nerve is located in his lateral wall (the anterior pontine membrane).