Basal CSF Cisterns

Basal cisterns are widened compartments within the subarachnoid space (between the pia and arachnoid mater) where CSF pools to form cisterns (Latin: box).

The suprasellar (chiasmatic) cistern is an unpaired cistern surrounding the pituitary infundibulum and optic chiasm.

It is formed as the interpeduncular cistern extends forward across the optic chiasm onto the upper surface of the corpus callosum. It is continuous posteriorly with the interpeduncular cistern.

Boundaries

• Anteriorly: posteroinferior border of the frontal lobes
• Laterally: uncus of the hippocampi gyri of the temporal lobe
• Posteriorly: the ventral surface of the mesencephalon and cerebral peduncles 
• Floor: diaphragma sellae and part of the planum sphenoidal
• Roof: posterior and anterior perforated substance and parts of the anterior and posterior wall of the basal recessus of the third ventricle

Shape

• Pentagonal – at the level of the optic chiasm
• Six-point star – at the level of the cerebral peduncles, due to different fissures/cisterns extending from the suprasellar space
  • Anteriorly: interhemispheric fissure
  • Anterolaterally: Sylvian fissure
  • Posterolaterally and posteriorly in the midline: interpeduncular cistern

Relations

• Anterior to the interpeduncular cistern
• Superior to the sella turcica
• Between the uncus of the temporal lobes
• Inferior to the hypothalamus

Contents

• The proximal part of the Sylvian fissure
• The optic chiasm
• Infundibular stalk
• Circle of Willis

The interpeduncular cistern is unpaired, cone-shaped and located between the cerebral peduncles of the midbrain.

Boundaries

• Superiorly: diencephalic leaf
• Inferiorly: mesencephalic leaf
• Laterally: medial borders of the cerebral peduncles
• Posteriorly: posterior perforated substance
• Anteriorly: the origin of the leaflets of the Lilliquist membrane

Contents

• Circle of Willis
• The proximal portion of the oculomotor nerve III
  • Courses in the lateral walls of the cistern
• peduncular posterior communicating
• median anterior pontomesencephalic veins
• vein of the pontomesencephalic sulcus

Relations

• Adjacent to the cural and ambient cisterns

The ambient cistern is a thin, sheet-like extension of the quadrigeminal cistern that extends laterally around the midbrain and posterior to the thalami

Contents

• Posterior cerebral artery
• Superior cerebellar artery
• Basal vein of Rosenthal
• Trochlear nerve

The quadrigeminal cistern (or superior cistern) The precise location is between the splenium of the corpus callosum and the upper surface of the cerebellum, i.e. dorsal to the midbrain. The cistern extends laterally around the midbrain, from the great cerebral vein to the third ventricle.

Boundaries

• Anterior wall – quadrigeminal plate of the midbrain (corpora quadrigemina) and posteromedial thalamic pulvinar
• Superior wall – splenium of the corpus callosum
• Floor – the upper half of the roof of the fourth ventricle (i.e., the superior medullary velum) and part of the cerebellar vermis, extending from the superior medullary velum and lingula to the culmen and the adjacent cerebellar hemisphere lobules,

Contents

• Pineal gland
• Part of the trochlear nerve
• Great cerebral vein
• Third portion of posterior cerebral arteries
• Third portion of superior cerebellar arteries