Temporal Arteritis

last authored: March 2011, Natalia Gorelik
last reviewed: April 2011, Ken Flegel

Introduction

Temporal arteritis, also known as giant cell arteritis or cranial arteritis, is a chronic vasculitis of large- and medium-sized vessels. It occurs almost exclusively in individuals over 50 years old, with a mean age of diagnosis of 72. Although it is a systemic disease, it most commonly involves cranial arteries originating from the aortic arch, particularly the temporal arteries. Involvement of these arteries causes anterior ischemic optic neuropathy which may lead to blindness. When giant cell arteritis affects the aorta, it results in aortitis and may lead to aneurysms formation as well as claudication in the extremities.

The Case of...

Theodora is a 66 year-old woman who developed recurrent headaches over the past two weeks accompanied by pain in the jaw when chewing and fatigue. She has also been suffering from pain in the hips and stiffness, which she blamed on osteoarthritis.
What should Theodora’s doctor ask and do?

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Causes and Risk Factors

The etiology and pathogenesis of giant cell arteritis remain unclear.

Amongst the possible causes is genetic susceptibility since the disease is more common in people with HLA-DR4 or HLA-DRB1. An infection with mycoplasma pneumoniae, parvovirus B19 and chlamydia pneumoniae may serve as the trigger for the onset of the disease.

Risk factors include:

Older than 50 years old
Female gender (female:male ratio is 2:1)
Non-black
Scandinavian descent
Having polymyalgia rheumatica (10 to 20% of patients with polymyalgia rheumatica develop temporal arteritis)
Heavy smoking and atherosclerosis, a risk factor for women, but not men

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Pathophysiology

Giant cell arteritis appears to be a maladaptive inflammatory response to arterial injury. This inflammatory reaction involves the cellular immunity, including macrophages, T cells, antigen-presenting cells, macrophage-derived inflammatory cytokines, and HLA molecules. It affects the arterial tunica media vasorum and tunica adventitia. Branches of the internal and external carotid arteries are the most commonly involved sites. Occlusion of these blood vessels leads to the clinical picture of ischemia (eg. claudication, loss of vision, headaches). Giant cell arteritis can also involve the mid-sized arteries of any other organ.

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Signs and Symptoms

history
physical exam

History

A complete history remains the best tool to diagnose giant cell arteritis. The most significant symptoms in making the diagnosis include neck pain and jaw claudication. Headache and myalgia are frequently seen, but they are not specific to temporal arteritis.

The manifestations of temporal arteritis are variable and often transient. They include:

Fever, sweats, malaise, fatigue, weight loss, anorexia
New onset of headaches (occurs in at least two-thirds of patients.)
Tender temporal arteries and scalp
Visual disturbances like diplopia, amaurosis fugax, and blindness
Claudication of the jaw or tongue (in about half of the patients)
Symptoms of polymyalgia rheumatica (stiffness and muscle pain in neck, shoulders, lower back, hips, and thighs)
Upper respiratory tract symptoms such as cough (consequence of vasculitis in the area of cough receptors)
Claudications in the extremities (3 to 15% of patients experience arm claudication)
Raynaud’s phenomenon
Strokes
Myocardial infarctions

Physical Exam

Findings on physical exam can include:

fever
tender, prominent, thickened, or nodular temporal artery,
diminished pulses
pulse discrepancies between the arms
auscultatory bruits over affected arteries
cotton wool spots and disc abnormalities on fundoscopy
murmurs of aortic regurgitation indicating ascending aortic aneurysm
limb gangrene

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Investigations

lab investigations
diagnostic imaging

Lab Investigations

increased ESR (greater than 50 mm/h)
increased CRP
increased platelet count
temporal artery biopsy: obtaining a biopsy segment of 3–5 cm with serial sectioning of biopsy specimens (shows
necrotizing arteritis with a predominance of mononuclear cells or a granulomatous process with multinucleated giant cells)
normochromic or slightly hypochromic anemia
increased serum IL-6
increased aspartate aminotransferase and alkaline phosphatase
decreased albumin
increased levels of IgG and complement

The first three items of the laboratory work-up are the most important in establishing a diagnosis of giant cell arteritis. A concomitant increase in ESR and CRP has a sensitivity of 88% and a specificity of 98%. An increased platelet count is highly specific (91%), but has a lower sensitivity (57%).

It is also important to note that a negative temporal artery biopsy does not rule out giant cell arteritis, as the granulomatous inflammation is not continuous throughout the blood vessel. Bilateral biopsies increase the likelihood of positive findings.

Diagnostic Imaging

Ultrasound of temporal artery may show stenoses, occlusions, and a halo sign (i.e. hypoechoicity around involved arteries)

Transthoracic echocardiography or chest CT may reveal thoracic aortic aneurysms which are 17 times more common in temporal arteritis patients than in matched controls

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Differential Diagnosis

The differential diagnosis includes:

Migraine
Glaucoma
Takayasu arteritis
Uveitis
Carotid plaque with embolic amaurosis fugax
Trigeminal neuralgia

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Treatments

The management of temporal arteritis aims at reducing symptoms and preventing visual loss.

Giant cell arteritis responds extremely well to glucocorticoid treatment. For uncomplicated disease, the therapy consists of 40 to 60 mg/d of prednisone for about 1 month, followed by a gradual tapering. When visual symptoms are present, it is important to initiate therapy immediately without awaiting for the pathology results. The treatment then consists of 3 days of 1000mg of intravenous pulse methylprednisolone followed by the same treatment as for uncomplicated temporal arteritis. Monitoring ESR and CRP to assess inflammatory activity helps in adjusting the tapering plan. An increase in ESR may be normal with decreased steroids and is not necessarily an indication of arteritis exacerbation, especially in a symptom-free person.

Relapses are frequent, occurring in about 60 to 85% of patients, and are palliated with an increased dosage of corticosteroids. Some studies report that addition of methotrexate might reduce the relapse rate, as well as shorten the course of steroid therapy.

Low-dose aspirin reduces the incidence of cranial ischemic complications and should be added to the glucocorticoid therapy.

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Consequences and Course

Often, temporal arteritis is self-limited and lasts several months or years. In most patients, glucocorticoid therapy can eventually be discontinued without complications. In a few patients, however, the disease is chronic and prednisone must be continued for years.

Overall, temporal arteritis does not seem to decrease longevity. Nevertheless, it may lead to serious complications such as visual loss, which occurs in about 15 to 20% of patients. Usually the visual loss is already present prior to the initiation of therapy. It rarely arises once treatment is started (1 per cent frequency). Amongst patients presenting with vision deficits, about 13% experience a progression in visual problems with treatment. Increased age is associated with a higher risk of developing bilateral blindness.

Another complication of giant cell arteritis is the development of aortic aneurysms, usually affecting the ascending aorta. Yearly chest x-rays may be useful to identify this problem.

Lastly, about half of the patients with giant cell arteritis will eventually develop polymyalgia rheumatica.

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