Concomitant Injury of Vagus and Hypoglossal Nerves Caused by Fracture of Skull Base: A Case Report and Literature Review

Injury of lower cranial nerves (CNs) by skull base fracture after head trauma can occur sometimes. However, selectively different CN damage on either side is extremely rare. A 53-year-old man had difficulty of swallowing, phonation, and articulation after falling off his bicycle. In physical examination, a deviated tongue to the right side was shown. Brain computed tomography showed a skull base fracture involving bilateral jugular foramina and right hypoglossal canal. Left vocal cord palsy was confirmed by laryngoscopy. Electromyography confirmed injury of left superior laryngeal nerve, recurrent laryngeal nerve, and right hypoglossal nerve. Video fluoroscopic swallowing study revealed large amounts of remnant in vallecula and pyriform sinus without opening of upper esophageal sphincter due to dysfunction of cricopharyngeus muscle. After constant rehabilitation for dysphagia, he was allowed to eat a general diet with compensatory techniques at discharge and further recovery after 3 months. Injury of lower CNs after fracture of the skull base can cause severe morbidity. However, the prognosis of such injuries can be favorable with early rehabilitation treatment by identifying the injured CN. A careful and accurate examination of lower CN injury in skull base fracture is essential for planning a treatment strategy.