Definition

Giant cell arteritis (GCA) is an inflammation of the lining of arteries. GCA is classified as arteritis or vasculitis, which refers to inflammatory conditions in blood vessels. Damage usually occurs to blood vessels in the head, neck, upper torso, and arms. In some cases, inflammation can also occur in medium-sized and large arteries.

The head, particularly the temples (temporal part), is the most common site of inflammation in GCA. GCA is also known as temporal arteritis. There may be swelling and damage to the blood vessels. If left untreated, the disease can lead to various complications, such as visual issues.

Causes

In GCA, inflammation occurs in the arteries of the scalp and head the most, particularly those above the temples (temporal artery). The temporal artery run above the ears to the scalp, branching off from the carotid arteries in the neck.

Inflamed blood vessels will become swollen. This swelling narrows the inside of the blood vessel, causing less blood to flow through it. As a result, the delivery of oxygen and nutrients to the tissue affected by the bleeding blood vessel decreases.

It is still unknown what causes artery inflammation, but it is believed to be caused by the immune system attacking the blood vessel walls. It is suspected that some genes and environmental factors may also increase your susceptibility to this condition.

Risk Factor

GCA affects adults over the age of 50, with the majority of cases occurring in the elderly aged 70-80. It is extremely rare to find the disease in patients under the age of fifty. GCA is also most common in caucasians from Northern Europe and Scandinavia.

Women are believed to be twice as likely as men to suffer from this condition. Sometimes the disease runs in families; patients may have family members who have GCA disease.

Symptoms

The most common symptom of GCA is a severe headache that usually affects both sides of the temples. The headache may be intermittent, worsen, or subside temporarily.

In general, signs and symptoms of GCA include:

• Severe persistent headache, typically in the temple. The pain may throb on one side or at the back of the head
• Tenderness if the scalp is pressed
• Jaw pain when the individual chews or opens the mouth widely
• Arms may hurt when used
• Fever and excessive fatigue
• Unintentional weight loss
• Muscle pain

If the inflammation that occurs in GCA also spreads to the ocular blood vessels, then patients can experience visual issues. This symptom can occur suddenly. Visual symptoms include blurred vision, double vision, or sudden vision loss.

Patients may experience GCA in conjunction with polymyalgia rheumatism (PMR), an inflammatory condition that causes muscle stiffness and pain, particularly in the shoulder and hip. Around 5 to 15 percent of patients with rheumatic polymyalgia will be diagnosed with GCA, and around 50% of GCA patients can also experience symptoms of PMR disease.

Diagnosis

GCA can be difficult to diagnose as the initial symptoms resemble other common diseases. Therefore, the doctor will try to rule out other possible causes of the patient's symptoms.

Aside from asking about your symptoms and medical history, the doctor will perform a thorough physical examination, focusing on the temporal arteries. Frequently, one or both arteries will be painful, with reduced pulsation and a hard, cord-like feel and appearance.

The doctor may recommend certain tests such as:

• Blood tests

The tests below may be used to help diagnose your condition and monitor your progress during therapy:

• • The blood sedimentation rate is used to determine whether or not there is inflammation occuring in your body.
  • C-reactive protein is used to measure a substance produced by the liver during inflammation

• Imaging tests

These tests can be used to diagnose GCA and monitor your response to therapy. These include:

• • Doppler ultrasound, which uses sound waves to produce images of blood flow through blood vessels
  • Magnetic resonance angiography (MRA) combines MRI and a contrast agent to produce detailed images of your blood vessels
  • PET (positron emission tomography) scan, which uses an injected liquid tracer that contains a small amount of radioactive material. PET scans can produce detailed images of your major blood vessels and highlight areas of inflammation

• Sampling

The best way to confirm a GCA diagnosis is to collect a small sample from the temporal artery close to the skin. The procedure is performed with local anesthesia. The sample will subsequently be examined under a microscope in the laboratory.

If you have GCA, your artery will often be inflamed, with abnormally large cells known as giant cells found under the microscoe, giving the disease its name. However, it is possible for someone to have GCA and have a negative biopsy result. If the results are unclear, your doctor may suggest a temporal artery biopsy on the other side of your head.

Management

Treatment aims to prevent severe complications such as vision loss, and should be started as soon as possible. If your doctor suspects you have GCA despite the fact that the results of the temporal artery tissue sample have yet to be released, treatment can begin before the results are available.

The medication used in therapy is corticosteroid, which have anti-inflammatory properties and suppress the immune system. The medicine will be administered in high doses for an extended period of time before being gradually reduced.

If corticosteroids are administered for an extended period of time, they can cause side effects, so the doctor will closely monitor the treatments. To counteract these potential side effects, your doctor will most likely monitor your bone density and may recommend calcium and vitamin D supplements or other medications to help prevent bone loss.

Complications

If left untreated, GCA can lead to serious complications such as:

• Blindness

A decrease in blood flow to your eyes can cause sudden and painless vision loss in one, or although rare, both eyes. Vision loss is usually permanent.

• Aortic aneurysm

An aneurysm is a bulge that forms on a weak blood vessel, typically the large artery that runs down the middle of the chest and abdomen (the aorta). Aortic aneurysms can rupture, resulting in life-threatening internal bleeding. You can read more about aortic aneurysms here.

• Stroke

Stroke, a condition where a blood vessel in the brain is blocked or ruptured, is a rare but possible complication of GCA.

Prevention

Since the cause is unknown, there is no way to prevent GCA. To minimize the effects of treatment, you can change your diet to a healthier one and exercise regularly.

When to See a Doctor?

If you have new, persistent headaches or any of the signs and symptoms of GCA, consult with a doctor immediately. If you are diagnosed with GCA, begin treatment as soon as possible to avoid vision loss.

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