AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Background

Giant cell (temporal) arteritis (GCA) confronts the neurologist in many ways. It should always be considered in the differential diagnosis of a new-onset headache in an elderly patient with an elevated erythrocyte sedimentation rate (ESR). Neuroophthalmologic complications, such as anterior ischemic optic neuropathy (AION), generally are well recognized, but many other neurologic problems can complicate the clinical course of GCA. Timely diagnosis and steroid treatment are essential for the prevention of potentially irreversible ischemic end-organ damage.

Temporal arteritis was first described in the Western literature by Hutchinson in 1890, and the histopathologic features were reported by Horton in 1932. Visual loss associated with temporal arteritis was first reported by Jennings in 1938, and Birkhead first introduced the effectiveness of systemic corticosteroid therapy in preventing blindness.

Pathophysiology

GCA is primarily a disease of cellular immunity. The vasculitic damage is mediated by activated CD4⁺ T helper cells responding to an antigen presented by macrophages. The primary inflammatory response affects the internal elastic lamina. Multinucleated giant cells, which are a histologic hallmark of GCA, may contain elastic fiber fragments. The actual inciting antigen remains unknown, but elastin remains an important suspect.

The superficial temporal artery is involved in most patients, providing a convenient biopsy site, but this is only the "tip of the iceberg." The topographic distribution of GCA, which reflects its predilection for the internal elastic lamina, includes the aortic arch and its branches.

GCA does not cause a widespread intracranial cerebral vasculitis, because intracranial arteries lack an internal elastic lamina. GCA does involve cervicocephalic arteries, including the carotid and vertebral arteries. It commonly affects arteries in the following pattern:

Intraorbital branches, especially the posterior ciliary and ophthalmic arteries, commonly are affected.

Vertebral arteries are involved as frequently as the superficial temporal arteries in fatal cases, although basilar artery involvement is rare.

Vertebral arteritis is extracranial, but it may extend intracranially for roughly 5 mm beyond dural penetration.

Subclavian, axillary, and proximal brachial arterial involvement produces a characteristic angiographic pattern of vasculitis, consisting of long, smooth, stenotic segments that alternate with nonstenotic segments and tapered occlusions.

Involvement by GCA of the ascending aorta can lead to aortic rupture, and coronary arteritis may result in myocardial infarction (MI).

Less often, the descending aorta and mesenteric, renal, iliac, and femoral arteries can be affected, with attendant complications of intestinal infarction, renal infarction, crural infarction, and ischemic mononeuropathies.

Pulmonary arterial involvement has also been described.

Pathogenesis and histopathologic findings

The pathogenesis of GCA is not known but probably has an idiopathic autoimmune etiology. A cellular immune reaction to elastin and an abnormality of the tunica media of affected vessels have been implicated.

In support of the elastin theory, disease severity has been shown to correlate with the amount of elastic tissue within the vessels, with the arteries most commonly affected being the superficial temporal, ophthalmic, occipital, vertebral, posterior ciliary, and proximal vertebral arteries. The intracranial circulation is typically spared because these arteries have very little elastic tissue. The theory also is supported by histopathologic findings of a disrupted, fragmented internal elastic lamina in affected vessels and the presence of characteristic giant cells close to the internal elastic lamina. Along with elevated serum levels of neutrophil elastase, deposition of elastase along the damaged internal elastic lamina has been described.

In patients with GCA abnormality of the tunica media of affected vessels is probably caused by ischemia, and presumably as a result of an immune-mediated response to the injured smooth muscle cells, secondary damage to the elastic lamina occurs. Histologically, the presence of macrophages and giant cells closely attached to the smooth muscle cells has been shown.

While evidence for humoral immunity includes elevated levels of circulating immunoglobulin and complement, and also immune complex/immunoglobulin and complement deposition in the inflamed vessel wall, support for cellular immunity includes the presence of giant cells, macrophages and monocytes, and lymphocytes in the inflammatory infiltrate. Increased frequencies of the HLA haplotypes B8, DR3, DR4, DR5, and DR(beta)1 are seen in patients with GCA.

Frequency

United States

The incidence of GCA in Olmsted County, Minnesota, increased between 1950 and 1975 from 5.1 to 17.4 incident cases per 100,000 population per year in persons aged 50 years and older. The increase was attributable to greater clinical awareness and improved rate of accurate diagnosis. On January 1, 1975, the prevalence was 133 cases per 100,000 in persons aged 50 years and older.

International

Few epidemiologic studies of GCA outside the US have been published, but incidence rates are not thought to vary significantly within the defined age-susceptible groups. The highest incidence is reported in Scandinavia, where 23.3-33.6 per 100,000 people older than 50 years are affected.

Prevalence heavily depends on the number of individuals aged 50 years or older; the mean age of onset is 75 years. Countries with a lower life expectancy have a lower prevalence.

Mortality/Morbidity

GCA has not been associated with a statistically significant increase in rates of death, stroke, or MI compared to an age-matched, community-based control population; however, it can lead to these outcomes.

• GCA leads to death by one of these mechanisms in roughly 2% of cases.
• As would be expected, the topographic extent and severity of the vasculitis is greater in fatal than in nonfatal cases.
• More difficult to quantify are the number of patients whose deaths are related directly or indirectly to chronic corticosteroid use and its attendant complications (eg, hip fracture).

Race

No racial predisposition to GCA is known, although existing epidemiologic studies are limited because they have been performed on predominantly Caucasian populations, suggesting that it is more common among them.

Sex

The female-to-male ratio is roughly 3.7:1.

Age

The median age of onset is 75 years. The age range in one series of 166 cases proven by temporal artery biopsy (TAB) was 55-92 years. Rarely described in those younger than 40 years, it is the most common systemic vasculitis affecting elderly patients.

• The following conditions are histologically similar but nosologically distinct from GCA and occur in different age groups: Juvenile temporal arteritis affects children; primary CNS vasculitis (originally termed granulomatous angiitis of CNS) can strike at any age, but it is far more likely than GCA to affect young adults.

CLINICAL

Section 3 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

History

The most commonly reported symptoms are headache (initial symptom in 33%, present in 72%); neck, torso, shoulder, and pelvic girdle pain that is consistent with polymyalgia rheumatica (PMR; initial in 25%, present in 58%); fatigue and malaise (initial in 20%, present in 56%); jaw claudication (initial in 4%, present in 40%); and fever (initial in 11%, present in 35%).

Nonspecific symptoms of cough and sore throat occur in 17% and 11%, respectively, but are rarely the presenting complaints. Amaurosis fugax occurs in 10% overall (initial symptom in 2%), and some degree of permanent visual loss occurs in 8% (initial symptom in 3%).

Less common symptoms, which are almost never the presenting complaint, include limb claudication (8%), transient ischemic attacks (TIAs) or stroke (7%), scintillating scotoma (5%), tongue claudication (4%), diplopia (2%), tongue numbness (2%), and myelopathic symptoms ( <1%).

• Headache and other craniofacial pain syndromes: The headache of GCA has no pathognomonic features, but typically, and most importantly, the headache is either new in a patient without a history of headaches or of a new type in a patient with a history of chronic headaches.
• • It is usually throbbing, generalized, and continuous. Focal temple pain is present with tenderness on direct palpation.
  • Scalp tenderness may be present with hair combing.
  • Less often, the pain may be predominantly occipital or occipitonuchal.
  • Other craniofacial pain complaints can include jaw claudication, tongue claudication, and facial pain (a rare symptom). Jaw claudication is almost pathognomonic of temporal arteritis, and it is a result of ischemia of the maxillary artery supplying the masseter muscles; it causes pain on speaking or chewing.
  • About 15% of patients report symptoms of carotodynia.
• PMR: Neck, torso, shoulder, and pelvic girdle pain may occur within the context of this syndrome.
• • PMR occurs in approximately 58%, and is the initial symptom in 25% of patients with GCA.
  • In typical cases of PMR without vasculitic involvement of the peripheral nervous system, electromyographic (EMG) results are normal.
  • Mild EMG abnormalities in an elderly patient that suggest a mild peripheral neuropathy are generally unrelated to PMR or to a vasculitis.
• Amaurosis fugax and visual loss: Amaurosis fugax occurs in 10-12% of patients with GCA, and permanent loss of vision due to AION occurs in 8-23%.
• • Prior to 1960, most series reported that patients with transient loss of vision went on to develop permanent, bilateral loss of vision due to AION.
  • Following monocular onset, the second eye became affected within days.
  • Today, amaurosis fugax often leads to prompt diagnosis and effective corticosteroid therapy.
• TIAs: Diagnosed entirely on the basis of historical data, TIAs are properly considered in this context.
• • Atherosclerosis, hypertension, and cardiac disease are the most important causes of cerebral infarction in the elderly with or without GCA, but the known propensity of GCA to affect carotid and vertebral arteries should be considered in GCA patients with TIAs and cerebral infarction.
  • Approximately 4% of patients with GCA experience TIA or stroke at some point during their illness, although how many specifically result from GCA is unclear.
  • A greater proportion of TIAs and infarctions occur in the vertebrobasilar territory than the carotid territory in patients with GCA than in the general population.
  • Few clinical features reliably distinguish a vasculitic from an atheromatous cause, although in rare instances, atheroembolic material has been observed funduscopically or angiographically in the setting of active GCA.
  • Vertebrobasilar events sometimes present as acute confusional states or coma as opposed to discrete focal syndromes.

• Confusion and encephalopathy: Encephalopathy is a rare complication of GCA; however, the differential diagnosis is extensive.

• Confusion may be due to steroids, either primarily (steroid psychosis) or secondarily from a steroid-induced metabolic derangement, or to systemic or CNS infections (including infections that occur in immunocompromised hosts).
• Unrelated causes include degenerative dementia, chronic subdural hematoma, sedating medications, and other diseases prevalent in the elderly.
• Acute encephalopathy may be caused by GCA itself as a result of cerebral infarction. Presumably, cognitive changes reflect thalamic, mesial temporal, and mesencephalic involvement in most cases. CT scan or, preferably, MRI should be done early in these patients.
• Acute encephalopathy is a poor prognostic sign. Many patients with this complication progress to coma and die.
• When recognized and treated promptly with increased dosages of steroids, patients can stabilize and, over time, experience some recovery.

Physical

Physical signs parallel symptoms and are dependent on the organ systems that are damaged by vasculitic ischemia.

• Superficial temporal artery inflammation: Signs are present in 49% of patients, including erythema, pain on palpation, nodularity, thickening, or reduced pulsation on the affected side. Although rare, ischemic necrosis of the scalp and tongue can occur.
• AION is caused by vasculitis of the posterior ciliary artery.
• • Less commonly, optic neuropathy is entirely retrobulbar. On rare occasions, blindness results from central retinal artery occlusion.
  • Ophthalmoscopy in acute AION may show sludging of blood in retinal arterioles, which can be orthostatically sensitive. Vision loss precedes the funduscopic changes of optic nerve infarction by roughly 36 hours. Acutely, the disc is pale with blurred margins.
  • As AION evolves, the absolute amount of disc elevation tends to be modest ( <3 diopters in most cases), with infrequent areas of disc hemorrhage. Edema resolves within 10 days or so; within 2-4 weeks, it is replaced by optic atrophy.
  • Residual visual field defects are usually altitudinal.
  • With retrobulbar involvement, optic pallor and atrophy gradually develop without antecedent papillitis.
  • Central retinal artery occlusion causes pallor and edema of the entire retina and optic disc together with a macular cherry-red spot.
• Oculomotor impairment: Diplopia occurs in roughly 2-14% of patients with GCA.
• • The oculomotor apparatus can be involved at any level, including the extraocular muscles (EOM), nerves, and brain stem. However, the most common site is the EOM.
  • A characteristic feature of EOM involvement is daily fluctuation of the ocular motility disorder.
  • Horner syndrome is uncommon, judging from a review of several large series; however, ptosis and miosis may occur together, separately, or in conjunction with other oculomotor disturbances.
• Peripheral nerve and muscle signs: The vasculitis of GCA can affect large peripheral arteries and their branches. When it involves the nutrient arteries of peripheral nerves, mononeuropathies or mononeuritis multiplex may result.
• • The incidence of acute ischemic mononeuropathies in patients with GCA is difficult to estimate but is probably around 2%.
  • Essentially all named peripheral nerves can be involved in ischemic mononeuropathies.
  • Among spinal nerve roots, the fifth cervical has been reported to be susceptible to GCA by several authors.
  • Patients with GCA can also develop mononeuropathies (which occur at common compression sites) unrelated to vasculitis. For example, approximately 5% have carpal tunnel syndrome. Some of these cases may be related to median nerve compression by synovitis related to PMR.
  • Elderly patients frequently have mildly abnormal nerve conduction studies and EMG suggesting a mild peripheral neuropathy, regardless of whether they have GCA. Once again, the relationship of such neuropathies to the systemic inflammatory state in some patients is uncertain. In other patients, antecedent ischemic mononeuropathies may occur and eventually resemble a "diffuse," severe, peripheral neuropathy.
  • GCA does not cause an inflammatory myopathy, although rare examples of localized muscular inflammation are known. PMR may lead falsely to the clinical suspicion of a myopathy. Steroid therapy commonly causes a mild, noninflammatory myopathy ("steroid myopathy").

• Myelopathy: A few cases of patients developing an acute cervical myelopathy within the context of active GCA have been reported.

• The vasculitis presumably extends to the anterior spinal artery from the vertebral arteries.
• Although rare, myelopathic involvement represents a serious complication and may presage a fatal outcome.
• Prompt treatment with corticosteroids may result in neurologic stabilization and improvement.
• Arterial bruits: Bruits in GCA reflect the topographic distribution of GCA.
• Carotid bruits occur in 10-20% of patients with GCA and are frequently bilateral.
• Among patients with bilateral carotid bruits, 60% also have upper limb bruits or claudication.
• Approximately 40% of patients with GCA who have carotid bruits experience an ischemic eye or brain complication (amaurosis fugax, TIA, permanent visual loss, or stroke), although permanent deficits (permanent visual loss and stroke) do not occur more often than in patients with GCA who do not have carotid bruits.
• Altered mental status: Recurrent episodes of acute encephalopathy with progressive cognitive impairment can lead to a chronic dementia in patients with GCA.
• This may occur as steroid dosage is tapered.
• Because these patients are elderly, they may be assumed incorrectly to have Alzheimer disease. Instead, they have a multiinfarct dementia due to cervicocephalic arterial involvement by GCA.
• CT scan and MRI demonstrate multiple areas of infarction, although EEG findings are inconsistent.
• These patients are typically on steroids, and their ESR may or may not be increased during these disease exacerbations. Higher dosages of steroids will not result in immediate cognitive recovery; however, longitudinal follow-up should show no further deterioration and may show modest improvement.
• Currently, encephalopathy or dementia is thought to be a rare occurrence, although earlier literature suggested that it was common.

Causes

The cause of this autoimmune disorder is not known. Although mycoplasma and parvovirus B19 infection have been implicated, it is generally accepted that they are only "innocent bystanders."

DIFFERENTIALS

Section 4 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Other Problems to be Considered

Dental conditions
Infections
Sinus disease
Granulomatous angiitis of the CNS
Wegener granulomatosis
Horner syndrome
Carotid disease and stroke
Dissection
Connective tissue disease

WORKUP

Section 5 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Lab Studies

• ESR is elevated in most patients, often to a high level (mean, 85 ± 32 mm in 1 h), although it is normal in roughly 3% of patients. ESR often drops when steroid therapy is started, even in patients with normal baseline.
• CBC reveals mild anemia in most patients, with a mean hemoglobin of 11.7 ± 1.6 g/dL; most have a mild thrombocytosis (mean platelet count, 427 ± 116 x 10 x 10⁹/L).
• Alpha-2 globulin and other acute phase reactants are elevated mildly but nonspecifically in 72%.
• Mild elevations in serum aspartate aminotransferase (AST) and alkaline phosphatase occur in 15%.

Imaging Studies

• Aortic arch and cerebral angiography
• • Vertebral and external carotid arteries (including the superficial temporal artery) may show vasculitic changes of alternating stenotic segments or occlusion. Superficial temporal artery angiography is less reliable than TAB for establishing a diagnosis.
  • Internal carotid arteries may be occluded, but they rarely have a characteristic vasculitic pattern.
  • Subclavian, axillary, and proximal brachial arterial involvement produces a characteristic angiographic pattern of vasculitis that consists of long, smooth, stenotic segments alternating with nonstenotic segments and tapered occlusions.
• On CT scan and MRI, the brain is typically unaffected by GCA, but in patients with a multiinfarct state due to cervicocephalic arteritis, CT scan and MRI demonstrate multiple areas of infarction.
• Because aortic or other vessel aneurysms are often asymptomatic, unless they rupture, it is prudent to screen all patients with GCA for large vessel disease with CT scanning.

Other Tests

• Superficial TAB is the confirmatory test that should be obtained, almost without exception, in patients in whom GCA is suspected clinically.
• • TAB is important because of the long, often complicated, treatment course for GCA and since the other diagnostic possibilities that can mimic many of the nonspecific features of GCA (eg, headache, body aches, fatigue) are myriad.
  • In one large clinical series, TAB was confirmatory in only about one third of patients in whom GCA initially was suspected. Because of this high negative rate, and because GCA produces "skip lesions" with normal intervening segments, large (5 cm) and, if necessary, bilateral TAB specimens should be obtained.
  • Biopsy of the most symptomatic side should be performed first and, if frozen sections are negative, a contralateral specimen should also be obtained.
  • In cases in which a large TAB section is obtained from the most symptomatic side, and multiple thin sections obtained, diagnosis can be made in 86% of cases with a unilateral TAB.
  • TAB should be performed as soon as possible after clinical suspicion is raised, but it should not delay therapy when the index of suspicion is high because of the risk of ischemic ocular and cerebral complications.

Histologic Findings

The histopathology of the diagnostic arterial lesion includes intimal proliferation with resulting luminal stenosis, disruption of the internal elastic lamina by a mononuclear cell infiltrate, invasion and necrosis of the media progressing to panarteritic involvement by mononuclear cells, giant cell formation with granulomata within the mononuclear cell infiltrate and, less consistently, intravascular thrombosis.

Involvement of an affected artery is patchy with skip lesions and normal intervening segments. It is commonly accepted that because of the patchy involvement of the arteries, biopsies may be nondiagnostic in many patients, and nondiagnostic biopsy specimens do not exclude the diagnosis of temporal arteritis. Some authors even suggest that biopsy may not be necessary (Pountain, 1995).

Furthermore, corticosteroid therapy, which should be started without delay, rapidly reduces the chance of a positive biopsy result. One week of corticosteroid treatment may reduce the chance of obtaining a positive biopsy result to 10%, further suggesting that biopsy should be performed within the first few days of therapy.

Steroid therapy may change the vasculitic appearance within days, and a previous vasculitic focus may appear normal or show only intimal fibrosis.

TREATMENT

Section 6 of 12  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Medical Care

Regardless of extent of neurologic involvement, oral corticosteroids remain the mainstay of treatment.

• Steroid-related adverse effects
  • The frequent and potentially serious consequences of chronic steroid therapy (eg, diabetes mellitus, vertebral compression fractures, steroid myopathy, steroid psychosis, immunosuppression-related infections) have led many to question the use of chronic steroid therapy.
  • Some studies have suggested that much lower doses and more rapid tapering schedules than currently used are sufficient. One such study advocated initiating treatment with 20 mg of prednisolone daily and tapering it to 10 mg daily within 3 months.
  • Many patients may respond to this regimen with symptomatic improvement of headache, PMR, and reduction of ESR; however, a substantial number of patients experience worsening of symptoms.
  • Headache and PMR, although the most common symptoms of GCA, are not reasons for using high doses of steroids.
  • Higher doses of steroids are required to prevent irreversible ischemic ophthalmologic and neurologic complications, which may be an early manifestation of GCA or, less commonly, develop during a flare.
  • Despite the apparent higher incidence of ischemic eye and brain complications in patients with carotid bruits, a bruit is not a sufficient indicator to base a decision between a high- or low-dose steroid regimen.
• Alternative immunosuppressant agents: Trials of other immunosuppressant agents, including azathioprine, methotrexate, dapsone, and cyclophosphamide, have been attempted for their steroid-sparing effects.
• • Steroid dosages have been lowered successfully but inconsistently in some patients on each of these drugs.
  • Toxicity can be a significant problem, particularly with dapsone and cyclophosphamide.
  • Azathioprine has no acute effect, and its steroid-sparing effects may not be evident for a year.
  • Limited experience suggests that cyclophosphamide may be the most consistently effective immunosuppressant. It may permit more rapid steroid tapering when instituted following a relapse.
  • Low-dose aspirin may be used as a prophylactic measure to prevent stroke because stroke may occur despite high-dose corticosteroid therapy and because almost all GCA patients have thrombocytosis.

• In most cases, the neurologist should consult with a rheumatologist and the treating internist before instigating treatment with any of these alternative immunosuppressive agents.

Consultations

GCA diagnosis and treatment involves neurologists, rheumatologists, ophthalmologists, neurosurgeons, and pathologists.

• Rheumatology: GCA crosses the subspecialties of neurology and rheumatology, and neurologists uncomfortable with the diagnosis and management of GCA should consider rheumatologic consultation.
• Ophthalmology: The funduscopic features of AION may require ophthalmologic consultation for diagnosis and treatment recommendations, particularly in subtle cases.
• Neurosurgery
  • Surgical consultation is necessary for TAB.
  • Depending on institution, this procedure can be performed by a neurosurgeon, plastic surgeon, or general surgeon.
• Pathology
• • That the treating neurologist be familiar and confident with the laboratory evaluating the TAB specimen is imperative, since this is the criterion standard for GCA diagnosis.
  • A myriad of laboratory errors (eg, specimen handling, fixation, sectioning) can, if they occur, result in a misdiagnosis (most often a false-negative result).

Diet

Patients with GCA who are on steroid therapy should be monitored carefully for the steroid-related complications of diabetes mellitus, hypertension, peripheral edema, and weight gain.

• Monitor dietary sugar, salt, and caloric intake to prevent such complications.
• Patients on chronic steroid therapy are also at risk for gastric ulcer disease and should be placed on H2 blockers or antacids.

Activity

No activity restrictions are necessary in a patient with GCA who is asymptomatic on adequate therapy.

• If a patient has ischemic eye or brain symptoms, then bedrest in a supine position may be desirable before or when first beginning steroid therapy.
• Some patients may have orthostatically sensitive amaurosis fugax, but this is rare.

MEDICATION

Section 7 of 12  

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• Differentials
• Workup
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• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Oral corticosteroids are the mainstay of treatment.

Drug Category: Glucocorticoids

These agents have anti-inflammatory properties. They cause profound and varied metabolic effects. In addition, they modify the body's immune response to diverse stimuli and inhibit the synthesis of TNF-alpha, IL-2, IL-6, and IFN-gamma. In addition, glucocorticoids modulate serum and leukocyte-bound levels of cell adhesion molecules.

Drug Category: Immunosuppressant agents

Inhibit key factors of the immune system.

FOLLOW-UP

Section 8 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Further Outpatient Care

• GCA is treated primarily in an outpatient setting. The median duration of symptoms before diagnosis is 1 month.
• • Ongoing monitoring of symptoms and ESR are mandatory.
  • ESR often normalizes within days of instituting steroid therapy.
  • With tapering steroid doses, ischemic complications may occur at any time but tend to occur a median of 1 month after beginning therapy.
  • The typical patient with GCA remains on steroid therapy for roughly 2 years.

Deterrence/Prevention

• No effective prevention strategies are known.

Complications

• Complications of GCA result from ischemic complications of vasculitis and are discussed in Clinical.
• Sequelae of steroid therapy include acute and chronic adverse effects and are discussed in Treatment and Medication.
• • Because of the high frequency of chronic adverse effects, TAB confirmation of diagnosis is highly desirable.
  • Patients with GCA suffer the following steroid-related complications during the course of their treatment: vertebral body compression fracture (26%), symptomatic steroid myopathy (11%), steroid psychosis (3%).

Prognosis

• With prompt, adequate therapy, full recovery is the rule.
• • The reduced rate of neuro-ophthalmologic complications in recent years reflects improved recognition and treatment.
  • Blindness is now a rare complication.
• Untreated, the prognosis for the patient with GCA is extremely poor, with blindness or death resulting from myocardial infarction, stroke, or dissecting aortic aneurysm. Vision loss in the second eye may occur even after the initiation of treatment (possibly because those vessels have already been affected by arteritis) in 6-13% of patients.
• While morbidity and mortality have improved significantly with corticosteroid therapy, a higher mortality after treatment and definitely a higher morbidity caused by the corticosteroids have been reported.

Patient Education

• Symptomatic relapse: Patients must be instructed concerning the seriousness of symptomatic relapses so that prompt medical attention is sought.
• Steroid use: Patients must know the importance of strictly adhering to their steroid dose schedule and, if necessary, must utilize ancillary interventions such as dietary restrictions that can reduce the incidence of steroid-related adverse effects.

MISCELLANEOUS

Section 9 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Medical/Legal Pitfalls

• GCA causes blindness, and this dread complication can be prevented with prompt diagnosis and institution of therapy. Failure to do so represents a medicolegal pitfall in addition to suboptimal medical practice.
• Steroid-related complications such as vertebral compression fracture can become a source of chronic pain and disability, but they are not prevented easily or reliably. To avoid misunderstandings, inform patients and their families about this and other potential complications that can occur even with proper therapy.

ACKNOWLEDGMENTS

Section 10 of 12  

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• Introduction
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• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

The authors and editors of eMedicine gratefully acknowledge the contributions of previous author, Richard J. Caselli, MD, to the development and writing of this article.

MULTIMEDIA

Section 11 of 12  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Media file 1:  Hematoxylin- and eosin-stained superficial temporal artery biopsy specimen, cross section. The hallmark histologic features of GCA shown here include intimal thickening with luminal stenosis, mononuclear inflammatory cell infiltrate with media invasion and necrosis, and giant cell formation in the media.
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Media type:  Photo

Media file 2:  Lumbar angiogram showing stenosis and occlusion of femoral artery branches due to vasculitis in the same patient whose temporal artery biopsy specimen in shown in Image 1.
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Media type:  X-RAY

Media file 3:  Hematoxylin- and eosin-stained femoral artery branch, cross section, taken from a lower limb amputation specimen from the same patient shown in pictures 1 and 2. Mononuclear cell invasion and necrosis in the media of this large artery can be observed. Extensive lower limb vasculitis from GCA resulted in ischemic necrosis of the lower limb, necessitating amputation.
	View Full Size Image
Media type:  Photo

REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
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• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

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Article Last Updated: Jul 10, 2006