Infraorbital neuralgia: A diagnostic possibility in patients with zygomatic arch

Neuralgia of the infraorbital nerve is an unusual cause of facial pain. The patient experiences paroxysmal or constant discomfort, often in the form of stabbing pain, in the distribution area of the infraorbital nerve. The sensation is associated with hypersensitivity to palpation in the infraorbital notch. The infraorbital nerve is a branch of the maxillary nerve. It originates in the infraorbital canal of the upper jaw and then follows the anterior and superior dental canal, branching off towards the incisor and canine roots and towards the mucous membranes of the anterior part of the inferior meatus. We present the case of a patient with left zygomatic arch pain refractory to medical treatment that was temporarily resolved with an infraorbital nerve block. Our patient was a man aged 39 years with no relevant medical history. He made an appointment with the headache service because he had been experiencing continuous burning pain with no apparent cause over a 16-month period. Pain intensity was 5 out of 10 on the visual analog scale (VAS, with 0 indicating no pain and 10, the worst pain imaginable); it was located in the left zygomatic arch. He also experienced infrequent exacerbations lasting about an hour during which pain intensity was 9/10 on the VAS. Neurological examination yielded the surprising finding that this pain could be provoked by palpation of the nerve in the infraorbital notch. No other concomitant data of interest were observed. Before attending our service, he had been assessed by the otorhinolaryngology and maxillofacial surgery departments. MRI and facial CT scans had been performed and neither yielded pathological findings. Pain responded partially to naproxen but did not abate with a daily dose of 200 mg of lamotrigine. Since we suspected neuralgia of the infraorbital nerve, we performed an anesthetic block with 1 cm of lidocaine. Cessation of pain for 2 weeks confirmed the diagnosis (code 13.7 in the second edition of the International Headache Classification [ICHD-2]). We later performed several anesthetic blocks that were temporarily effective. Results did not change on the one occasion when anesthetic block was associated with a cor-