Patients may refer localized facial pain to the eye. Common sources of facial pain include dental disorders and sinus disease. Other facial pain syndromes include trigeminal neuralgia, glossopharyngeal neuralgia, temporomandibular joint (TMJ) syndrome, and herpes zoster neuralgia. The last can be associated with facial and/or auditory nerve involvement in herpes zoster oticus or Ramsay Hunt syndrome. The onset of facial pain in an elderly patient may indicate GCA. Facial pain is occasionally a sign of nasopharyngeal carcinoma or perineural infiltration of skin cancer (squamous cell, basal cell, or melanoma) affecting the trigeminal nerve or dura at the base of the brain.
Trigeminal neuralgia, also known as tic douloureux, typically occurs during middle age or later. It is essential to differentiate primary (classic) trigeminal neuralgia (no obvious cause and completely normal examination in between episodes) from secondary (symptomatic) trigeminal neuralgia, in which a lesion affecting the trigeminal nerve can be identified. In 80%–90% of cases, the neuralgia is caused by vascular compression of CN V, although secondary trigeminal neuralgia may also result from demyelinating disease, an infiltrative process, or a posterior fossa mass lesion. In primary trigeminal neuralgia, the pain is almost always unilateral (95%) and involves V2 or V3; involvement of V1 alone is rare (<5%) and suggests a secondary cause. Chewing, tooth brushing, or a cold wind may precipitate paroxysmal burning or electric shock–like jabs, which last seconds to minutes. There may be periods of remission.
Sensory function in the face should be normal on testing in primary trigeminal neuralgia; hypoesthesia, anesthesia, or dysesthesia increases the likelihood of a secondary cause. These patients should have neuroimaging of the posterior fossa, preferably MRI. Treatment options include use of the medications gabapentin, pregabalin, carbamazepine, phenytoin, baclofen, clonazepam, and valproic acid; selective destruction of trigeminal fibers (rhizotomy); or surgical decompression of CN V in the posterior fossa.
Excerpted from BCSC 2020-2021 series: Section 5 - Neuro-Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.