Abstract:

Objective　To study micro-anatomical features of cisterns and their arachnoid membranes in pineal region.　Methods　Cisterns in pineal region including their shapes, borders, contents and arachnoidal membranes were observed in 20 cadaveric brains using an operating microscope.　Results　 Arachnoid membranes of the pineal region include the arachnoidal envelope, the posterior perimesencephalic membrane and the cerebellar precentral membrane. At the level of the tentorial apex, arachnoid membranes covering the inferior-medial surface of occipital lobe and the superior surface of cerebellum converge to form the arachnoidal envelope, which encloses the vein of Galen with its tributaries, the pineal gland and the suprapineal recess. The posterior perimesencephalic membrane arises from the outer arachnoid membranes covering the inferior occipital lobe and the superior cerebellum at the tentorial edge. It surrounds and is attached to the dorsal mesencephalon. The cerebellar precentral membrane originates from the arachnoid membrane covering the superior cerebellum where it meets with the arachnoidal sleevelet, and is attached to the inferior colliculus anteroinferiorly. The quadrigeminal cistern borders the superior cerebellar cistern by the cerebellar precentral membrane, the posterior pericallosal cistern by the arachnoidal sleevelet and the posterior ambient cistern by the ascending part of the posterior perimesencephalic membrane; the posterior ambient cistern borders the cerebellomesencephalic cistern by the horizontal part of the posterior perimesencephalic membrane. Conclusion　The borders, communications and relationships between cisterns in pineal region as well as their arachnoid membranes were redefined in this study.

Key words: Cisterns, Arachnoid membranes, Pineal region, Microanatomy, Neurosurgery