Giant-cell arteritis (GCA) occurs when the lining of the arteries becomes inflamed. The condition most often affects the arteries in the temple and is sometimes referred to as temporal arteritis. GCA can lead to other complications, including blindness, stroke, or aortic aneurysm.
Definition & Facts
Giant cell arteritis rarely occurs in individuals under the age of 50 and is most common in those between the ages of 70 and 80. Women are diagnosed with GCA at twice the rate of men. Caucasians of Scandinavian or northern European descent and people with a family history of GCA are the most at risk of developing the condition.
There is also a significant link between giant cell arteritis and another inflammatory disorder called polymyalgia rheumatica that causes muscle pain and stiffness, primarily in the shoulders, neck, and hips. About one-half of patients with GCA also experience symptoms of polymyalgia rheumatica. Between five and 15 percent of patients with polymyalgia rheumatica are also diagnosed with GCA.
Symptoms & Complaints
Less typical symptoms of giant cell arteritis include fever, a dry cough, and profound anemia. Eyesight can be affected if GCA occurs in the arteries supplying blood to the eyes. Vision problems can include double vision, blurring, or even permanent blindness. Permanent vision loss can typically be prevented with prompt treatment.
Although the exact cause of giant cell arteritis is not known, the symptoms are the result of swelling in the lining of the arteries that restricts the flow of blood carrying vital nutrients and oxygen throughout the body. The inflammation is due to a response by the body’s immune system; however, what triggers the immune system is not clear.
While GCA is most common in the arteries of the scalp and head, it can affect any medium-sized artery. It is possible for the condition to affect only sections of an artery, leaving normal areas in between. Certain genetic factors may make an individual more susceptible to developing giant cell arteritis.
Diagnosis & Tests
The early symptoms of giant cell arteritis can mimic a number of other conditions, which can make it difficult to diagnose. As a result, patients suspecting they have GCA may wish to ask for a referral to a rheumatologist specializing in inflammatory conditions affecting the blood vessels.
A variety of tests and procedures may be used to confirm the diagnosis and rule out other conditions. A physical examination will typically reveal temporal arteries that are hard and tender to the touch, have a cord-like appearance, and have a reduced pulse.
The results of blood tests for erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), will often be elevated, indicating inflammation. The most definitive way to diagnose giant cell arteritis is through a biopsy. The procedure is performed on an out-patient basis and involves obtaining a small sample of tissue from one of the temporal arteries. The biopsy is done under local anesthetic and causes only minimal discomfort and scarring.
In cases of giant cell arteritis, the tissue sample will show inflammation and abnormally large cells when examined under a microscope. Since GCA may not affect the entire artery, it is possible to get a false negative biopsy result. If this occurs, the doctor may suggest a repeat biopsy on the temporal artery on the other side of the head.
Imaging tests, including magnetic resonance angiography (MRA), Doppler ultrasound, and PET scan can all be used to get a detailed view of the arteries and to identify areas of reduced blood flow and potential inflammation.
Treatment & Therapy
Giant cell arteritis is normally treated with prednisone or another high-dose corticosteroid. Treatment is often started even before the diagnosis is confirmed to prevent sudden vision loss. Symptoms of GCA often start to improve within a few days of starting treatment; however, any blindness that occurred prior to treatment is most likely permanent.
Most patients continue the steroid therapy for one to two years. In some instances, the doctor will slowly decrease the dosage after approximately one month to find the lowest dose possible to keep the inflammation under control. During this time, it is not unusual for patients to experience a recurrence of the headaches and to develop symptoms of polymyalgia rheumatica. This can typically be treated by increasing the steroid dose slightly or by adding another drug called methotrexate.
Long-term steroid therapy can cause significant side effects, including bone loss, muscle weakness, jitteriness, difficulty sleeping, weight gain, and hypertension. To prevent osteoporosis, the patient may be advised to take vitamin D supplements, calcium supplements, or other medications designed to preserve bone mass.
Lifestyle changes, dietary modifications, and medications may be used to control blood pressure. Most of the side effects should resolve once the steroid therapy is completed. Giant cell arteritis rarely recurs following treatment.
Prevention & Prophylaxis
- Getting regular exercise—Aerobic exercise and weight-bearing exercises help preserve bone mass, control blood pressure, ward off weight gain, and improve cardiovascular function. It can also improve overall mental outlook and create a sense of well-being. Patients should consult with their doctor before starting any exercise regimen to ensure that it is safe and appropriate based on their circumstances.
- Eating a healthy diet—A diet that emphasizes lean protein, whole grains, and fresh fruits and vegetables can help prevent health conditions ranging from osteoporosis to diabetes mellitus and hypertension.
- Follow up—Patients with GCA should consult with their doctor on a regular basis and have follow-up doctor's visits to ensure that the treatment is effective and to identify potential complications.
- Consider taking aspirin—Low-dose aspirin therapy may help reduce the risk of blindness and stroke associated with giant cell arteritis. Patients should seek their doctor’s advice before starting an aspirin regimen.