Type I Chiari malformation presenting with isolated unilateral hypoglossal nerve and vocal cord paralysis

Chiari malformation refers to caudal displacement of posterior fossa structures through the foramen magnum in the cervical canal and is classified according to the severity of displacement and accompanying cranial nerve and cervical pathologies. We presented a 24-year-old male patient who had isolated unilateral paralysis of the hypoglossal nerve and vagus nerve, with thyroid cartilage asymmetry. Chiari type I malformation was diagnosed by craniospinal magnetic resonance imaging. Suboccipital craniectomy and cervical 1-level large partial laminectomy were performed by the neurosurgery department. No improvement was observed in hypoglossal and vagal paralysis during an 18-month follow-up.