Unilateral separation of the hypoglossal nerve from the cranial cavity through two hypoglossal foramina: case report

The twelfth cranial nerve, known as the hypoglossal nerve, is a somatomotor nerve. Functionally, it innervates the intrinsic muscles of the tongue and all extrinsic tongue muscles except the palatoglossus. Anatomically, the hypoglossal nerve exits the cranium via the hypoglossal canal. This case report describes a variation identified during routine dissection of two adult cadavers in the dissection laboratory of the Karabük University Faculty of Medicine, Department of Anatomy. During the standard dissection procedure, the cranial cavity was first exposed, and the brain tissue was removed. Subsequent examination revealed that, in one cadaver, the hypoglossal nerve on the left side exited the cranium through two separate small foramina instead of the typical hypoglossal canal. A review of the literature indicated that reports on this anatomical variation are scarce. This case report aims to contribute valuable insights to the field of anatomy and provide critical information for clinicians performing surgical procedures in this region.