Bademci, G.Batay, F.Yaşargil, M. G.2020-06-252020-06-252006closedAccess0946-7211https://doi.org10.1055/s-2006-948299https://hdl.handle.net/20.500.12587/3746Objective: Cadaveric dissections were performed to review the intracranial and extracranial course of the hypoglossal nerve. The neurological significance of a newly defined "triple cross" of the hypoglossal nerve is discussed. Materials and Methods: 10 cadaveric heads (left and right; 20 sides) were dissected using microsurgical techniques. Results: In the cisternal segment of hypoglossal nerve, the diameter of the rostral trunk amounted to 155-680 mu m (mean 435 mu m), and the caudal trunk to 210-820 mu m (mean 482 mu m). The roots formed three trunks in 20% of the hypoglossal nerves and two trunks in the rest. As a first cross, the anterior medullary segment of the vertebral artery crossed the hypoglossal nerve roots in 14 of 20 sides (70%). As a rare variation, the vertebral artery extended medial to the nerve (25%) or between its roots (5%). The second cross was found between the descendens hypoglossus and the occipital artery (75%), sternocleidomastoid artery and vein complex (15%) and external carotid artery (10%). The third cross was shown in the submandibular triangle between the lingual hypoglossus and its drainage vein; vena committans nervus hypoglossus. Conclusion: Throughout its way, the hypoglossal nerve passes over vascular structures in three crossing points which may serve as a probable cause of hypoglossal nerve entrapment disorders.eninfo:eu-repo/semantics/closedAccesshypoglossal nervetriple crosscross-compressionentrapment disordersmicrosurgical anatomyArticle49423423710.1055/s-2006-9482992-s2.0-3375021649317041836N/AWOS:000241635400010Q3