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Temporal Arteritis
(Giant Cell Arteritis)
Robert L. Tomsak, MD, PhD
Temporal arteritis, also known as giant cell arteritis or cranial arteritis, is a vasculitis that affects the arteries of the head and neck. The mean age at presentation is 70 years. White women are affected somewhat more often than white men and the disease is less common in African Americans, Hispanics, and Asians. Temporal arteritis is a chronic disease that may recur even if treated and may be fatal.The pathogenesis is immunologic, and the inflammatory response involves platelet-derived growth factors, interferon-gamma, macrophages, and interleukins 1, 2, and 6. Increased endothelin-1 levels may play a role in ischemic complications. Atypical clinical presentations are well documented.
Overlap between polymyalgia rheumatica and giant cell arteritis exists. Between 16% and 21% of patients with polymyalgia rheumatica have a positive temporal artery biopsy and 40% to 60% of patients with giant cell arteritis have symptoms of polymyalgia rheumatica.
The main clinical features of temporal arteritis are:
| Ophthalmologic Manifestations | Neurologic Manifestations |
| Anterior ischemic optic neuropathy (most common presentation) Posterior ischemic optic neuropathy Ischemic retinopathy, central retinal and cilioretinal artery occlusions Amaurosis fugax Diplopia Ophthalmoplegia, ptosis, and miosis Anterior segment ischemia Marginal corneal ulceration Uveitic glaucoma Orbital apex syndrome Tonic pupil Eye pain |
Neuropathies Transient ischemic attacks and strokes Neuro-otologic (e.g., lingual infarction) Tremor Neuropsychiatric (e.g., depression, visual hallucinations) Myelopathy |
Occult giant cell arteritis presenting with visual signs or symptoms (e.g., biopsy-proven giant cell arteritis with no systemic symptoms) is well described.
Blood Tests
Although the Westergren sedimentation rate is most commonly used because of its sensitivity, it is a nonspecific test. Plasma fibrinogen concentration is useful for diagnosing and after disease activity in temporal arteritis because of its well-defined upper and lower limits of normality (200 mg to 400 mg), and because, in most cases, the sedimentation rate is predominantly determined by plasma fibrinogen concentration. Hayreh and colleagues found that a C-reactive protein value above 2.45 mg/dL in association with a Westergren sedimentation rate of 47 mm/hr or more gave a specificity for diagnosis of 97%. The presence of antiphospholipid antibodies and/or thrombocytosis has proved useful for diagnosis of temporal arteritis in some hands.
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Temporal Artery Biopsy
Temporal artery biopsy is the definitive test for temporal arteritis. A simple method for performing a temporal artery biopsy is as follows:
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The classic histologic picture of temporal arteritis is marked by intimal thickening and destruction of the internal elastic lamina (99%) associated with dense granulomatous inflammation including lymphocytes, histiocytes and giant cells (66%), and fibrinoid necrosis (12%). Healed arteritis is characterized by fragmented and lost internal elastic lamina, medial fibrosis, and scarring, although the ability to diagnose healed arteritis is controversial. Combining data from 20 reports totaling 2,680 patients, the overall positivity rate for temporal artery biopsies is 39%.
How large should a biopsy specimen be? Chambers and Bernardino showed that a biopsy as small as 4 mm, if serially sectioned meticulously, results in a false-negative result rate of less than 1%. Another report showed that multiple sectioning improved the yield of positive biopsies by 8.9%, but concluded that the extra work needed was not cost effective. Skip areas exist and false-negative biopsies have been reported with incidences ranging from 5% to 61%. These conflicting statistics highlight the importance of the pathologist’s role in the diagnosis of temporal arteritis.
Can a temporal artery biopsy be performed after beginning steroid treatment? A common myth regarding temporal arteritis is that the biopsy must be performed before starting systemic steroid treatment. However, a number of reports show that steroid treatment has little or no effect on biopsy positivity.
Therefore, steroid therapy must start immediately in any case of suspected temporal arteritis. The biopsy should be scheduled in a timely but non-emergent fashion. Bilateral simultaneous biopsies increase the diagnostic yield by approximately 3%.
Intravenous Fluorescein Angiography
Choroidal filling defects have been demonstrated by intravenous fluorescein angiography in anterior ischemic optic neuropathy caused by giant cell arteritis but not in the nonarteritic variety of anterior ischemic optic neuropathy.
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Corticosteroids
Oral prednisolone in a daily dose of at least 40 mg must be given. Patients who present with symptoms of a strong inflammatory response — fever, weight loss, sedimentation rate .85 mm/hr, and anemia — require higher initial doses of corticosteroids and longer duration of therapy.
Intravenous methylprednisolone, 250 mg to 500 mg four times a day, has been advocated for patients with acute vision loss from temporal arteritis. However, this approach may not be protective of progressive vision loss. Furthermore, aggressive treatment with intravenous steroids improves visual loss approximately 4% of the time and does not have a long-term steroid sparing effect. Complications include hypertension, diabetes, osteoporosis, compression fractures, and myopathy, and can occur twice as often in patients older than 75 years of age.
Other Drugs
Dapsone, methotrexate, and infliximab, an anti-tumor necrosis factor, have been used as alternative treatments for temporal arteritis.
Temporal arteritis is a chronic disease that requires periodic monitoring of symptoms and laboratory values. Blumberg and others reported the case of an elderly woman with biopsy-proven disease who developed recurrent clinical symptoms 9 years later and whose repeat biopsy was positive for acute temporal arteritis. Therefore, once the diagnosis of temporal arteritis is made, life-long monitoring for recurrence is mandatory.
