Unilateral Isolated Hypoglossal Nerve Palsy Secondary to Tonsillitis

Hypoglossal nerve palsy is usually associated with glossopharyngeal nerve, vagus nerve, and accessory nerve palsy, and the occurrence of hypoglossal nerve palsy alone is rare. We report a case of a 41-year-old man with unilateral isolated hypoglossal nerve palsy. The patient was aware of a leftward deviation of the tongue along with pharyngeal pain. The pharyngeal pain was quickly relieved by antibiotic treatment, but the deviation of the tongue did not improve, and the patient was referred to our hospital. As a result of the medical examination, a single paralysis of the left hypoglossal nerve and mild swelling of the left lingual tonsil up to the left palatine tonsil were observed. Various tests were performed, but there were no significant abnormal findings other than a suggestion of mild tonsillitis. We diagnosed the patient as idiopathic or tonsillitis-induced unilateral hypoglossal nerve palsy and started medical treatment with corticosteroids and methylcobalamin. The hypoglossal nerve palsy showed a tendency to improve after one month of onset and was almost cured by two months of onset.