Temporal arteritis: A strange disease with potential risk

Temporal arteritis - Giant cell arteritis - Cranial arteritis or Horton's disease are all names for a group of inflammatory blood vessel diseases. Usually appear in middle-aged people, causing a lot of discomfort for patients. If not diagnosed and treated early, it can lead to permanent blindness or even death.

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• 1. Introduction
• 2. Symptoms and causes
• 3. How is GCA diagnosed?
• 4. Treatment of temporal arteritis
• 5. Monitoring temporal arteritis

1. Introduction

Around the world, giant cell arteritis (also known as temporal arteritis) because this disease causes inflammation of medium and large blood vessels, including the aorta. The aorta is the artery that originates from the heart, and is the largest blood vessel, supplying blood to the entire body.

Giant cell arteritis (GCA) is a systemic disease. Which means it affects almost every medium, large blood vessel in the body. The main site of effect is the layer of cells lining the inside of the blood vessel - the vascular endothelium.

Structure of arteries

It is the most common vascular disease in the world. The group of blood vessels affected are the intracranial vessels, especially those that are the direct branches of the aorta (usually the external carotid artery and its branches). Of these, the most commonly affected artery is the temporal artery.

The prevalence of the disease

In the US and Europe, 1 in 100 women and 1 in 200 men will develop GCA at some point in their lives. The disease mainly occurs in subjects > 50 years old, most often at the age of 70 - 79 years. Because 80% of GCA patients are > 70 years old.

However, this ratio is different for Asians. Studies in Japan show that this ratio is only 1.47/100,000. In other words, only 1-2 people have GCA in 100,000 people over the age of 50.

Rheumatoid Arthritis (Polymyalgia Rheumatica) is a common comorbidity with GCA. In the United States, 20% of patients with polymyalgia rheumatica have GCA, and 50% of patients with GCA have rheumatoid arthritis. However, this number also decreased proportionately among Asians. Only 30% of patients with GCA have rheumatoid arthritis.

2. Symptoms and causes

2.1. The cause to the illness

This is a systemic immune disease. In other words, the disease is caused by the body's own immune cells (T-lymphocytes; monocytes). They attack the medium and large arteries of the body. Immune cells manipulate and convert macrophages (usually with the function of eating bacteria) into malformed, giant cells (with many nuclei). These giant cells give rise to the name: giant cell arteritis. It is also these malformed giant cells that secrete substances that change the structure of blood vessels. This will reduce the amount of blood to the area that the corresponding artery feeds.  

The image on the left shows the microstructure of a normal artery. Right image is GCA acquired artery, lumen narrowed

2.2. Common symptoms (30-80% of cases) 

• Fever:

Present in up to 50% of cases of GCA, but usually a low-grade fever. However, up to 15% of patients have a fever of 39 degrees Celsius. Therefore, it is easy for doctors to misdiagnose GCA with an infectious disease. In the US, due to the high number of people infected with GCA, in elderly patients with systemic symptoms as above, but no infection or cancer is found, GCA should be considered.

• Wasting syndrome:

Fatigue, loss of appetite, weight loss, night sweats, depression are usually mild, unknown, however, like fever, sometimes very prominent. 

• Anemia:

Usually isochromic isochromic anemia (a form of anemia unrelated to nutrition).

• Headache:

It is the main symptom of GCA that causes patients to come to the doctor. The typical headache in GCA is sudden, intense primarily in the temporal region (because the temporal artery is most commonly affected). However, headaches can occur in the back of the head (occipital), forehead, or top of the head. Because headache can be a symptom of cranial artery blockage. So when pressing on the corresponding scalp area, the patient will feel pain.

The temporal artery is dilated, taut, nodular

Indeed, compared with patients who did not have headaches, the doctor pressing pain on the skin on the head was only seen in 5.4% of cases. As for GCA subjects with headaches, this number was up to 38.9%. 

When examining the temporal artery, it can be seen that the artery is dilated, thickened, and tender. The pulse of this artery may be reduced or lost.

• Jaw claudication:

Approximately 50% of GCA cases have experienced a sensation of jaw stiffness. Jaw stiffness is usually triggered by continuous and prolonged talking or chewing. The two major features of jaw stiffness in GCA are abrupt onset with eating and severe pain afterward. Sometimes patients do not self-report this symptom, requiring the doctor to ask directly.

Jaw stiffness is closely related to the lack of blood supply because the cerebral vessels are affected by GCA. 54% of GCA patients have symptoms of jaw stiffness.

2.3. Uncommon symptoms (<20% of cases="">

• Eye symptoms:

Transient partial or complete loss of field of vision (Amaurosis fugax): Usually affects only one eye, sometimes both. This is an early sign of GCA pathology. This symptom is caused by lack of blood supply to the optic nerve (cranial nerve II), or rarely, retinal blood vessel damage. With partial visual field loss, patients may complain of a veil covering part of their eye (“shade covering one eye”). If the patient is permanently blind in one eye, and still has not received GCA treatment, blindness in the other eye may follow 1-2 weeks in 25-50% of cases. 

In contrast, if only one eye is affected and the other is normal, a full-dose treatment will prevent almost 100% of damage to both eyes. Remarkably, only 44% of patients with permanent blindness develop transient visual field loss.

• Double vision (seeing 1 thing into 2)

It is an uncommon manifestation of GCA.

Double look

• Fundoscopy:

Should be performed early in patients with signs of visual impairment. The finding of GCA on ophthalmoscopy is usually ischemic optic neuritis.

Sometimes, the complete blindness of one eye or even both sides of the patient is due to inflammation of the blood vessels in the brain, leading to the patient having a stroke. The lack of blood to the brain, especially in the image recognition part, will make the patient permanently blind.

• Painful dysphagia:

Often accompanied by a stiff jaw, due to inflammation of the blood vessels supplying the oropharynx. Leads to anemia to feed.

• Respiratory symptoms:

Dry cough. The mechanism causing this symptom is not really clear. May be due to lack of blood supply to the mucous membranes sensitive to cough.

• Extremity pain:

May be due to rheumatic pain (more common – about 30% of cases in Asians). Or less commonly (about 25% of cases) is due to inflammation of the blood vessels in the hands and feet, in this case, the patient's hands and feet may swell.

With vasculitis in the hands and feet, the patient will experience pain when moving the affected limb, sometimes with numbness. Symptoms are usually most obvious in the hands, and can spread to the forearm or even the arm. The blood vessel in the hand that is most often affected is the subclavian or axillary artery (10-15% of cases). Murmurs in these areas may be present (sound of blood swirling through the narrowing).

• In addition, you can find:

The pulse is absent or the pulse is weaker on one side than the other. Blood pressure in both arms (or legs) is not the same. Patients with this limb pain usually do not have a typical GCA presentation. Therefore, it will be easy to miss the disease. 

2.3. Symptoms are very rare (<5% of cases="">

• Cerebral infarction:

Indeed, GCA can cause cerebral infarction due to changes in vascular structure. Manifestations of stroke may be: weakness, coma, dizziness, unsteadiness, inability to walk, blindness (due to damage to the visual brain area).

Signs of a stroke to watch out for

• Dissecting aortic aneurysm:

This is an extremely dangerous disease. The patient can die at any time. GCA increased the risk of aortic dissection 17-fold compared with patients without GCA. This disease usually presents very late. Usually after other early symptoms have manifested, or even disappeared. Therefore, patients with GCA should have a straight chest x-ray every year to rule out aortic dissection aneurysms.

Left: Chest X-ray with aortic dissection aneurysm. Right picture: Normal chest X-ray

• There are also symptoms such as:
  • Heart attack.
  • Aortic valve regurgitation.
  • Hard tongue.
  • Deaf.
  • Peripheral neuropathy.
  • Tissue gangrene (of the scalp, tongue or extremities).

See the doctor:

• Take pulse and measure blood pressure: The difference between the two hands is too large suggestive of vascular damage.
• Examination of the temporal artery: The temporal artery is large, distended; failed to catch the pulse; Painful tenderness is suggestive of temporal artery injury.
• Listen for murmurs: In the carotid artery, subclavian artery, abdominal aorta, in the heart.
• Examine the bottom of the eye.
• Check shoulder, neck, and hip mobility. Because in patients with rheumatoid arthritis, the range of motion of these joints is narrowed. It means that you can't move freely, reach your full range.

Test:

• A blood count suggests anemia and a normal white blood cell count.
• Blood albumin decreases and will recover quickly with treatment.
• Elevated liver enzymes, especially ALP. Usually mild and reversible after treatment.
• ESR (erythrocyte sedimentation rate) is usually elevated but can be normal.
• CRP increases in nearly all cases.

3. How is GCA diagnosed?

Usually, we can diagnose GCA when ≥ 3/5 of the criteria set forth by the American Rheumatology Association:

• Age of onset ≥ 50 years old.
• New headaches appear.
• Examination revealed temporal artery abnormalities.
• Elevated erythrocyte sedimentation rate ≥ 50mm/hour.
• Abnormalities on vascular biopsies.

However, because symptoms are often atypical, GCA should be suspected in patients ≥ 50 years of age with:

• New headaches that appear or change from previous ones.
• Sudden blindness, especially transient blindness.
• Hard jaw.
• Fever, unexplained isochromic anemia or wasting syndrome.
• Increased CRP or increased erythrocyte sedimentation rate.

When temporal arteritis is suspected, we perform:

Temporal artery biopsy is the gold standard to help diagnose GCA. That is, if the biopsy results say that the damage is caused by GCA, that means the patient has GCA.

Biopsy of the temporal artery 1 segment 1-2 cm

Doppler ultrasound of blood vessels of the head and hand is an alternative to biopsy. If GCA is still suspected, but both biopsy and doppler ultrasound are not positive, the doctor may perform CT vascular, MRI vascular to help diagnose.

4. Treatment of temporal arteritis

Treatment in patients with suspected GCA should be instituted prior to biopsy results. Because biopsies often give results late (about 2 weeks) while treatment will help patients improve quickly.

In most cases, patients will be treated with high-dose oral corticosteroids. If the patient loses vision, intravenous corticosteroids will be administered. If symptoms do not improve dramatically after 5 days of treatment, then other diagnoses should be considered. This is true even when the biopsy is positive for GCA.

The course of treatment usually lasts 1 month or when the symptoms are completely gone. After that, continue to take the medicine, but gradually reduce the dose. Aspirin use may help reduce the risk of blindness in GCA patients. When the patient reappears when the corticosteroid dose is reduced. At this point stronger immunosuppressive drugs such as methotrexate (MTX) will be used.

5. Monitoring temporal arteritis

GCA patients treated with high-dose corticosteroids should be closely monitored. Re-examination every 2-4 weeks.

• Will the patient be monitored to see if the disease recurs?
• Are there acute complications of corticosteroid therapy? (gastritis, hyperkalemia, infection).

In patients with recurrent GCA, the chronic complications of this treatment should be evaluated:

• Osteoporosis.
• Diabetes.
• Depression.
• Dry beads.
• Wet beads.
• Cushing's syndrome.

To evaluate for aortic inflammation (which is often a late sign), chest CT can be performed on patients every 2 to 3 years after initial therapy.

Temporal arteritis or giant cell arteritis is a rare disease in Asians. Because of this, it will be difficult to diagnose this disease. Temporal arteritis can progress to blindness and death if not diagnosed and treated promptly.

Diagnosis is mainly based on:

• Symptoms of the patient upon inquiry and examination.
• Biopsy of the temporal artery.
• Doppler ultrasound of the arteries.
• Patient response to high-dose corticosteroid trial.

With proper and timely treatment, the patient's symptoms will improve dramatically. Monitoring during and after treatment is essential. The doctor will evaluate the treatment complications as well as the patient's aortic damage.