Cranial and cerebral base and its landmarks (Figs. 1 to 9)

Abstract

Neuronavigatory landmarks for surgery are bony structures, as long as bony structures are preserved during surgery.

But bony neuronavigatory landmarks are only related to adjacent cisternal structures, if the covering dural layer is thin.

However, the dural layers close to the upper basal cisterns are usually thickened, especially in the cavernosus area (Fig. 1).

Intradural structures may shift during surgery. Landmarks may be inexact, due to brain shift. Intraoperative orientation using modern ultrasound methods does not allow identification of fine vessels, nerves, or arachnoid structures.