Also known as temporal arteritis or cranial arteritis, this is the most common form of vasculitis that occurs in adults. It causes the inflammation of the lining of arteries — the blood vessels that carry oxygen-rich blood from your heart to the rest of your body. Most often, it affects the arteries in your head, especially those in your temples. For this reason, giant cell arteritis is sometimes called temporal arteritis or cranial arteritis. Almost all patients who develop giant cell arteritis are over the age of 50. Your arteries are pliable tubes with thick, elastic walls. Oxygenated blood leaves your heart through your body’s main artery, the aorta. The aorta then subdivides into smaller arteries that deliver blood to all parts of your body, including your brain and internal organs.With giant cell arteritis, some of these arteries become inflamed, causing them to swell and sometimes decreasing blood flow. Just what causes these arteries to become inflamed isn’t known. Since the disease is relatively uncommon and because it can cause so many different symptoms, the diagnosis of temporal arteritis can be difficult to make. With appropriate therapy, temporal arteritis is an eminently treatable, controllable, and often curable disease.
Giant cell arteritis can be difficult to diagnose because its early symptoms resemble those of many common conditions. For this reason, your doctor will try to rule out other possible causes of your problem. To make the diagnosis doctors at BRAINS, therefore, resort to a combination of physical exam, blood tests, biopsies and scans (see Tech & Procedure).
Treatment for giant cell arteritis consists of high doses of a corticosteroid drug such as prednisone. Because immediate treatment is necessary to prevent vision loss, your doctor is likely to start medication even before confirming the diagnosis with a biopsy. You should start feeling better within just a few days, but you may need to continue taking medication for one to two years or longer. After the first month, your doctor may gradually begin to lower the dosage until you reach the lowest dose of corticosteroids needed to control inflammation as measured by sed rate and CRP tests. Some of your symptoms may return during this tapering period.
Blood tests to check your erythrocyte sedimentation rate — commonly referred to as the sed rate. This test measures how quickly red blood cells fall to the bottom of a tube of blood. Red cells that drop rapidly may indicate inflammation in your body.You may also have to go through a test that measures C-reactive protein (CRP), a substance your liver produces when inflammation is present. The same tests may be used to follow your progress during treatment.
Biopsy: The best way to confirm a diagnosis of giant cell arteritis is by taking a small sample (biopsy) of the temporal artery. Because the inflammation may not occur in all parts of the artery, more than one sample may be needed. The procedure is performed on an outpatient basis during local anesthesia, usually with little discomfort or scarring. The sample is examined under a microscope in a laboratory.
If you have giant cell arteritis, the artery will often show inflammation that includes abnormally large cells, called giant cells, which give the disease its name.
Magnetic resonance angiography (MRA): This test combines the use of magnetic resonance imaging (MRI) with the use of a contrast material that produces detailed images of your blood vessels. Let your doctor know ahead of time if you’re uncomfortable being confined in a small space because the test is conducted in a tube-shaped machine.
Doppler ultrasound: This test uses sound waves to produce images of blood flowing through your blood vessels.
Positron emission tomography (PET): Using an intravenous tracer solution that contains a tiny amount of radioactive material, a PET scan can produce detailed images of your blood vessels and highlight areas of inflammation.