||Andrew G. Lee, MD, Chairman, Department of Ophthalmology, The Methodist Hospital, Houston, TX, Professor of Ophthalmology, Weill Cornell Medicine; Chelsea Livingston, Baylor College of Medicine, Class of 2022
||Summary: • GCA is most common in elderly (age > 50) • Presenting symptom = headache anywhere in the distribution of the external carotid artery • Associated symptoms: scalp tenderness, jaw claudication, vision loss o Vision loss -Transient: amaurosis fugax -Permanent: anterior ischemic optic neuropathy (AION) • Nonarteritic (NAION) - not caused by giant cell arteritis • Arteritic (A-AION) - caused by giant cell arteritis -Permanent: central retinal artery occlusion (CRAO) • Unusual presentations: transient diplopia, cranial nerve palsies, orbital manifestations that look like orbital inflammatory pseudotumor • Laboratory tests: o Erythrocyte sedimentation rate (ESR) o C-reactive protein (CRP) o Platelet count • Diagnostic procedure: o Temporal artery biopsy (TAB) • Treatment: o Corticosteroids (before TAB) -If no vision loss -give oral 1-1.5 mg/kg -If vision loss -give IV high-dose methylprednisolone -If patient develops steroid-related side effects, switch to: -Methotrexate -Tocilizumab -Other steroid-sparing regimen [Transcript of video] "The presenting symptom is headache, and there is no defining characteristic of this headache. It can be in the temple, it can be in the face, it can be in the ear, it can be in the neck - anywhere in the distribution of the external carotid artery. Pain in the face or headache in an elderly person should be considered GCA until proven otherwise. And we're going to ask about scalp tenderness and pain in the jaw when chewing, which we call jaw claudication. That jaw claudication is not often present, but when it is present it's very suspicious for external carotid artery distribution ischemia. Just like limb claudication is an ischemic sign, jaw claudication is an ischemic sign. And the patient may or may not have vision loss. If they do have vision loss, it can be one eye or both eyes; it can be mild, moderate, or severe; it can be transient vision loss (amaurosis fugax) or it can be permanent vision loss. And the most common cause of the vision loss is anterior ischemic optic neuropathy. So, as you know, we have a swollen disc, an RAPD, loss of vision - AION - anterior ischemic optic neuropathy. And that could either be nonarteritic (NAION) (not giant cell) or it could be arteritic (A-AION) (it is giant cell). So every patient who has NAION, we need to make sure it's not arteritic before we call it NAION. And the other way it can cause vision loss is a central retinal artery occlusion, a non-embolic CRAO. You should know that there are some unusual presentations of giant cell: transient diplopia, cranial nerve palsies, and orbital manifestations that look like orbital inflammatory pseudotumor. But in general, it's an elderly patient with headache and loss of vision. The laboratory tests that we do - sed rate (ESR) and CRP. But even if the sed rate and CRP are normal, we still would be considering giant cell arteritis. Normal test does not exclude the diagnosis. The third part of the triad of the testing is the platelet count, and thrombocytosis is often seen as an acute phase reactant in GCA. The diagnostic procedure of choice is the temporal artery biopsy (TAB). And were going to give corticosteroids before we get the temporal artery biopsy. So normally it's disease, diagnose, treat. With giant cell arteritis it's disease, treat, and then diagnose with the temporal artery biopsy or covering the patient with high dose corticosteroids until we get the biopsy result. Most papers would say if they don't have the vision loss that we can get away with oral 1 to 1.5 milligrams per kilogram, but if they have vision loss, I think we should probably consider an intravenous high-dose methylprednisolone. Or if they have amaurosis fugax, a non-embolic central retinal artery occlusion, or pallid edema - which are all very characteristic signs of giant cell arteritis in the eye - I'd give those intravenous methylprednisolone. And there's some anecdotal evidence to suggest that IV steroid might be better in that scenario. Most patients are going to have to be on steroids for a very long period of time - average duration months (18-24 months). And if they start developing steroid-related side effects, they might have to have methotrexate or some other steroid-sparing regimen or switch to the monoclonal antibody tocilizumab, the interleukin-6 blocker. I would strongly suggest that every patient who you start on steroids for giant cell arteritis, you coordinate their care with their internist or rheumatology so they can manage the steroid-related side effects and assist with the steroid-sparing regimen. So in summary, every elderly patient who has headache or pain of any kind in the external carotid distribution with or without vision loss from AION or CRAO, with or without transient or permanent diplopia, with or without amaurosis fugax, should undergo a sed rate, a CRP, and a platelet count to look for the acute phase reactants and then start on steroids and have a temporal artery biopsy."