This anatomic study describes the course and intracranial relations of the hypoglossal n. in 32 cadavers. The rootlets of the nerve emerged as a fan-shaped distribution (23.44%) or in two bundles (76.56%) and converged towards the hypoglossal canal in the subarachnoid space before piercing the dura mater. In 76.57% of cases the rootlets pierced the dura mater in two separate apertures, less commonly through the same aperture (21.87%), and in rare cases through three individual apertures, as in one of our cases. The distance between the two apertures varied from 0.6 mm to 8.7 mm. Commonly, the two bundles converged together and left the skull through one foramen in the skull. However, in some cases (28.12%), the hypoglossal canal was divided in two by a small bony spicule. In 23.45% of cases the initial course of the posterior inferior cerebellar a. (PICA) passed between the two bundles of the hypoglossal n. before ascending towards the lateral border of the fourth ventricle.
|Journal||Surgical and Radiologic Anatomy|
|Publication status||Published - 1 Jan 1998|
- Hypoglossal canal
- Hypoglossal nerve
- Posterior inferior cerebellar artery