A Case of Ophthalmic Branch Trigeminal Neuralgia in the Emergency Department

This case report describes a middle-aged patient with a past history of migraine headaches, who presented to the emergency department with a new onset of headaches around his left eye that were different from the pattern and character of his usual migraine headaches. The pain was severe, brief, and stabbing in nature, lasting only seconds, and occurring over intervals of a few minutes. His vital signs, including glucose, were normal. He had no constitutional symptoms, a normal neurological examination, and a normal head, eyes, ears, nose, and throat examination. The painful paroxysms could not be elicited on palpation of his face, head, or oral mucosa. His blood investigations were reported as within normal limits. He was not using alcohol or any illicit drugs and was not taking any medication. A diagnosis, with supportive imaging, of ophthalmic branch trigeminal neuralgia (TN) was made. His pain responded well to treatment with carbamazepine. TN is characterized by brief and intermittent lancinating pain with or without a constant background level of pain in the sensory distribution of one or more branches of the trigeminal nerve. There are three main causes for TN: idiopathic, the classical type resulting from neurovascular compression, and the secondary type typically due to multiple sclerosis, a space-occupying lesion, or a skull base abnormality. The mandibular and maxillary branches are most affected and can often be affected simultaneously. Ophthalmic branch TN is relatively rare. Virtually all of TN cases are unilateral and most are the classical type. Distinguishing TN from other cephalalgias, ocular pain, dental pain, or other pathology is critical to a proper diagnosis and initiation of effective therapy. Identifying trigger zones is important and carries a high diagnostic yield; however, they may be anatomically difficult to access, or in a refractory period during a physical examination. Physicians should be aware of several red flags associated with a suspected case of TN. Carbamazepine is the first-line treatment for TN, capable of reducing pain in 90% of patients. Failure to respond to medication requires further investigation and/or specialist referral. Untreated or unrecognized TN can have significant impacts on a patient's quality of life.