Giant cell arteritis (GCA)

2021-07-31 10:35 AM

Giant cell arteritis (GCA) is an inflammation of the lining of the arteries - the blood vessels that carry oxygen-rich blood from the heart to the rest of the body.

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Define

Giant cell arteritis (GCA) is an inflammation of the lining of the arteries - the blood vessels that carry oxygen-rich blood from the heart to the rest of the body. Usually, it affects the arteries in the head. For this reason, giant cell arteritis is sometimes called temporal arteritis or cranial arteritis.

Giant cell arteritis frequently causes headaches, jaw pain, and blurred or double vision. Blinded infrequently, stroke is the most serious complication of giant cell arteritis.

Treatment with corticosteroids often relieves symptoms of giant cell arteritis and can prevent vision loss. You will probably start to feel better the day you start treatment.

Symptoms

The most common symptoms of giant cell arteritis are headache and pain that is often severe. Some people, however, have pain only in one temple or in the front of the head.

Signs and symptoms of giant cell arteritis can vary. For some people, the onset of the condition feels like the flu, with muscle aches all over the body (myalgia), fever and fatigue as well as headaches.

In general, signs and symptoms of giant cell arteritis include:

Heaviness in the head and persistent pain, usually in the temporal region.

Reduced vision or double vision.

The scalp is sensitive, it can be painful to brush your hair or even put your head on a pillow, especially where the arteries are inflamed.

Jaw pain when chewing.

Sudden, frequent loss of vision in one eye.

Fever.

Unintentional weight loss.

Pain and stiffness in the neck, arms, or hips are common symptoms of a related disorder, polymyalgia. About half of people with GCA also have rheumatic polymyalgia.

If you have new, ongoing headaches or any of the problems listed above, see your doctor without delay. If diagnosed with GCA, starting treatment as soon as possible can often help prevent blindness.

Causes

Arteries are flexible, thick, elastic tubes. Oxygen blood from the heart through the aorta. This aorta then divides into smaller arteries that supply blood to all parts of the body, including the brain and internal organs.

With giant cell arteritis, some of the arteries become inflamed, causing them to swell. What causes the arteries to become inflamed is not known.

Although most large and medium arteries can be affected, swelling usually occurs in the temporal arteries in the head, which are located just in front of the ears and continue up the scalp. In some cases, swelling affects only part of the artery.

Risk factors

Although the exact cause of giant cell arteritis is not known, certain factors may increase the risk, including:

Age. Giant cell arteritis affects almost exclusively older people, the average age at onset is 70, and it rarely occurs in people younger than 50.

Sex. Women are about twice as likely to develop giant cell arteritis than men.

Geography. Although giant cell arteritis can affect anyone, people born in Nordic countries appear to have higher levels. People of Nordic descent are, particularly at risk.

Multi-joint pain. People with painful polyarthritis, which causes stiffness and pain in the neck, shoulders, and hips, have an increased risk of giant cell arteritis. About 10 to 15 percent of people with polyarthritis also have giant cell arteritis.

Complications

Giant cell arteritis can cause the following complications:

Blind. This is the most serious complication of giant cell arteritis. The swelling that occurs with giant cell arteritis narrows blood vessels, reducing the amount of blood and thus vital oxygen and nutrients reaching the body's tissues. Reduced blood flow to the eye can cause sudden painless loss of vision in one eye, in rare cases in both eyes. Unfortunately, blindness is usually permanent.

Aortic aneurysm. Having giant cell arteritis increases the risk of aneurysms. An aneurysm forms in a weakened blood vessel, usually in the aorta, the large artery that runs down the center of the chest and abdomen. An aortic aneurysm is a serious condition because it can rupture, causing life-threatening bleeding. Because it can occur soon after the initial diagnosis of giant cell arteritis, your doctor may monitor the health of your thoracic aorta annually with X-rays or other imaging tests such as ultrasound, CT scan, or MRI.

Stroke. In some cases, a blood clot can form in an affected artery, obstructing blood flow completely, depriving the brain of some of the oxygen and nutrients it needs, and causing a stroke. This serious condition is a rare complication of giant cell arteritis.

Testing and diagnosis

Giant cell arteritis can be difficult to diagnose because its initial symptoms resemble those of more common conditions. For this reason, your doctor will try to rule out other possible causes of the problem.

To help diagnose giant cell arteritis, some or all of the following tests may be ordered:

Clinical examination. In addition to asking about your symptoms and medical history, your doctor may perform a comprehensive physical exam, paying particular attention to the temporal arteries. Usually, one or both arteries.

Blood tests. If your doctor suspects giant cell arteritis, a blood test may be done to check the erythrocyte sedimentation rate — commonly known as the sed rate.

This test measures how well red blood cells settle to the bottom of a blood tube. Rapidly settling red blood cells can indicate inflammation in the body. There may also be tests for CRP, a substance the liver produces during inflammation. The same tests may be used to monitor progress during treatment.

Biopsy. The best way to confirm the diagnosis of giant cell arteritis is by taking a small biopsy sample of the temporal artery. Because inflammation can occur in all parts of the artery, more than one sample may be needed.

This procedure is performed on an outpatient basis under local anesthesia, usually with little discomfort or scarring. The sample will be examined under a microscope in the laboratory. If giant cell arteritis is present, the arteries will often show inflammation that includes large abnormal cells, called giant cells.

Unfortunately, biopsies are not straightforward. It is possible to have giant cell arteritis and still have a negative biopsy. If the results aren't clear, your doctor may recommend a biopsy of the temporal artery on the other side of your head.

Although the standard experimental biopsy of the temporal artery is for the diagnosis of giant cell arteritis, imaging tests can also be used to diagnose giant cell arteritis and to monitor treatment. Testing may include:

MRI/angiography. This test combines the use of magnetic resonance imaging (MRI) with the use of a contrast material that creates detailed images of blood vessels.

Supersonic. These machines use sound waves to create images of blood flowing through blood vessels.

Positron emission tomography (PET). Using an intravenous tracer containing a small amount of radioactive material, a PET scan can create detailed images of blood vessels and highlight areas of inflammation.

Treatments and drugs

Treatment of giant cell arteritis includes high doses of corticosteroid drugs such as prednisone. Because immediate treatment is needed to prevent vision loss, your doctor may start medication even before the diagnosis is confirmed with a biopsy.

Start feeling better within just a few days, but you may need to continue taking the medicine for one to two years or longer. After the first month, the doctor may gradually begin to reduce the dose until the lowest dose of corticosteroid needed to control inflammation is reached as measured by the CRP ratio and the sed test. Some symptoms may return during this time.

What are corticosteroids?

Corticosteroids are powerful anti-inflammatory drugs that mimic the effects of hormones produced by the adrenal glands. Medications can relieve pain, but long-term use, especially in high doses, can lead to some serious side effects.

Older adults, who are more likely to be treated for giant cell arteritis, are especially at risk for side effects including:

Osteoporosis.

Hypertension.

Muscle weakness.

Glaucoma disease.

Cataract.

Side effects of corticosteroid therapy include:

Weight gain.

Increased blood sugar, sometimes leading to diabetes.

Skin bruising.

Decreased function of the immune system, resulting in slow wound healing.

To reduce the potential side effects of corticosteroid treatment, your doctor may monitor your bone density and may prescribe calcium and vitamin D supplements or other medications to help prevent bone loss. Your doctor is also capable of monitoring blood pressure and may recommend an exercise program, dietary changes, and medications to keep blood pressure within a normal range. Most side effects go away when corticosteroid treatment is stopped.

New treatments

Researchers are trying to find treatments that have fewer side effects than corticosteroids cause.

One drug under investigation is methotrexate, which is commonly used to treat certain cancers and some inflammatory conditions such as rheumatoid arthritis. The hope is that by using both methotrexate and prednisone to treat people with giant cell arteritis, it will be possible to use less prednisone. Preliminary study results are contradictory, so further research is needed.

Ask your doctor about taking between 81 and 100 mg of aspirin per day (antiplatelet). Taken daily, aspirin can reduce the risk of blindness and stroke.

Lifestyle and remedies

When giant cell arteritis is diagnosed and treated early, the prognosis is usually excellent. Symptoms improve rapidly once corticosteroid therapy is started, and vision is not likely to be affected. The biggest challenge, in this case, maybe dealing with any side effects of the medication. The following suggestions may help:

Eat a healthy diet. Eating well can help prevent potential problems, such as osteoporosis, high blood pressure, and diabetes. Emphasize fruits and vegetables, whole grains, lean meats, and fish, while limiting salt, sugar, and alcohol. Be sure to get enough calcium and vitamin D. Experts recommend between 1,000 and 1,500 mg of calcium and 800 international units (IU) of vitamin D per day. Check with your doctor to see the right dose.

Exercise regularly. Regular exercise, such as walking, can help prevent bone loss, high blood pressure, and diabetes. Also beneficial for the heart and lungs. Additionally, many people find exercise improves their mood and overall well-being. If not exercising, start slowly and build up step by step, with a goal of at least 30 minutes on most days. Your doctor can help plan an appropriate exercise program.

Coping and supporting

Learning everything you can about giant cell arteritis and treating it can help you feel in control of the condition. The healthcare team can answer questions, and online support groups can also be of help. Know the possible side effects of any medication, and report any health changes to your doctor.