ABSTRACT
Vagal mononeuropathy is very rare. Diabetes mellitus is one of the causes of this rare disease condition. Here we report a 44-year-old woman who presented with an idiopathic vagal mononeuropathy and was finally diagnosed with diabetic vagal mononeuropathy. She presented with isolated dysphagia without hoarseness or other symptoms related with vagal dysfunction. Except for diabetes mellitus, no abnormalities were found by routine and specific checkups including brain imaging, gastroscopy, electromyography, and laryngoscopy. Finally, 12 days later, she abruptly developed hoarseness without other cranial nerve dysfunction.We suggest that her neurological symptoms originated from diabetes affecting the vagus nerve in isolation. Clinicians should pay attention to this association, especially when they encounter a patient with diabetes mellitus with sudden idiopathic dysphagia even without problems of vocalization.