A case of hypoglossal nerve palsy caused by a vertebral artery aneurysm found due to fasciculation of the tongue

Hypoglossal nerve palsy (HNP) with fasciculation of the tongue is unusual, but occasionally occurs as the initial or solitary sign of an intracranial lesion. We report a case of HNP caused by a vertebral artery aneurysm which was found due to fasciculation of the tongue. A 40-year-old man was referred to Iizuka Hospital because of lingual deviation and slight dysarthria. Intraoral examination showed hemiatrophy in the right side of the tongue with fasciculation and deviation towards the right side on protrusion. There were no other clinically significant neurological findings. Magnetic resonance imaging and an angiographic examination revealed a vertebral artery aneurysm, which was treated by proximal arterial occlusion of the vertebral artery to prevent rupture and subsequent subarachnoid hemorrhage. The postoperative course was favorable, without any serious sequelae. This case demonstrates the importance of investigating the possibility of intracranial lesions in patients who have HNP with fasciculation of the tongue.