Trigeminal Neuralgia —Symptoms, Diagnosis, Classification, and Related Disorders—

Trigeminal neuralgia (TN) causes sudden, usually unilateral, severe, brief stabbing recurrent pains in the distribution of one or more branches of the trigeminal nerve. Radiological examination is not required, however, patient interview and physical examination are necessary for diagnosis alone. When a patient is diagnosed with TN, an MRI is recommended to exclude tumor, cyst or multiple sclerosis, irrespective of the patient's age. From the etiological viewpoint, TN is classified into primary or idiopathic TN and secondary or symptomatic TN. From the symptomatic viewpoint, TN is classified into typical TN and atypical TN. Atypical TN, trigeminal neuropathy, pretrigeminal neuralgia, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) are also described.