Dura Mater of the Anterior Cranial Fossa

Abstract

The dura mater of the cranium is composed of an outer fibrous layer and an inner fibrous layer. The outer layer acts as the inner periosteum of the adjacent cranial bones. In the anterior fossa the fibers of the outer layer radiate from the frontal tuber, passing downward and medially. The dura is thinned in the area of the olfactory fossa, and the dura on the planum sphenoidale consists of transverse fibers grouped into thicker bundles. The inner layer of the dura mater is relatively thin. Between the two layers are the larger branches of the dural vessels, which give off small branches to the cranium and to the dura itself. The major vessels of the cerebral dura mater (and of the bones of the anterior fossa) are the ethmoidal arteries and the frontal branch of the middle meningeal. The ethmoidal arteries anastomose with various nasal arteries, while the frontal branch of the middle meningeal anastomoses with branches of the ethmoidal arteries and also with branches of the ophthalmic artery. In our material we occasionally found a branch of the internal carotid artery entering the most posterior portion of the floor of the anterior cranial fossa (Yasargil et al. 1984 identified this branch consistently). In the frontal midline approach to the skull base, attention must be given to the superior sagittal sinus, which extends only part way to the skull base, and to the falx cerebri. The falx carries a relatively large branch of the anterior ethmoidal artery called the anterior falceal artery. All the dural arteries interanastomose with one another and with the contralateral homonymous vessels. Venous drainage from the dura mater generally follows the course of the dural arteries.