Temporal arteritis
Definition
Temporal arteritis is a disease that causes inflammation and sometimes blockage of medium and large arteries in the head (often near the side of the head or temples).
Description
The mechanism responsible for temporal arteritis (also called giant cell arteritis) is complex and can affect medium and large size arteries, but commonly strikes the temporal artery causing temporal located headaches. In affected arteries there is an abnormal reaction that causes the infiltration of immune cells, such as lymphocytes, multinucleated giant cells, and plasma cells. Frequently the arteries in the head and neck are involved, but vasopathy can extend to the carotids and aorta. The abnormal mechanism is a cell-mediated immune response that is abnormally directed on an antigen (a foreign protein) near the elastic tissue component of an arterial wall. This immune response causes an infiltration of immune cells in an artery which could damage or even completely block the affected blood vessel. The exact cause of temporal arteritis (TA) is unknown. TA can be serious in cases where there is involvement of blood vessels that supply blood to the affected eye (i.e., posterior ciliary artery a branch of the ophthalmic artery) which can cause visual impairment.
Demographics
The disorder is more commonly observed in persons older than 50 years. TA occurs frequently with the occurrence ranging from 10 in 100,000 to 50 in 100,000. Internationally, there seems to be a higher incidence in countries higher in northern climates. The disorder occurs more frequently in Caucasian persons of northern European descent. TA rarely occurs in Blacks and Asians and it is four to six times more frequent in women than men. The mean age of onset is 70 years and the disorder is rarely seen in persons younger than 50 years. Long term survival is the same as for the general population. Visual loss is the most worrisome complication and can occur in over 50% of persons who are untreated, which could result in blindness for 20–50% of these patients.
Causes and symptoms
The cause of TA is not known. It is thought to be due to an immune cell response that attacks a foreign chemical (called an antigen) in the elastic layer of arteries in the head and neck.
In over 85% of affected persons, the most universal symptom is headache. The headache is severe and tends to be on one side (unilateral), and worsens at night. The pain tends to increase as days go by. Visual impairment may be the first presenting symptom since approximately 50% of patients complain of a sudden and painless visual loss. Loss of vision may be transient or permanent and blindness can occur if the condition is untreated.
In approximately 65% of persons, jaw claudication is prominent when chewing, swallowing or talking. Patients may have low grade fever and the effected arteries may be tender, warm, pulseless, dilated and thickened. Other symptoms that can occur include cough, anorexia, muscle aches, malaise, difficulty hearing, fatigue, fever/sweats and depression.
Diagnosis
Criteria for the diagnosis of TA were established in 1990 by the American College of Rheumatology. A diagnosis based on criteria for giant cell arteritis includes the presence of three of the following five items:
- new onset of headache or localized pain in the head region
- temporal artery tenderness to palpation
- development of symptoms in a person over 50 years of age
- lab result of over 50 for a special test called the Westergren Erythrocyte Sedimentation rate (WESR)
- decreased pulsations in head arteries, which cannot be attributed to arteriosclerotic disease of neck (cervical) arteries
A definitive diagnosis is made by the temporal artery biopsy which can be performed as an outpatient procedure (same day surgery).
Blood tests may reveal a high white blood cell count (leukocytosis), mild anemia or an increase in platelet cells (thrombocytosis), which are responsible for blood coagulation. Approximately 50% of patients affected with temporal arteritis have abnormal liver function tests. Chest radiograph may be useful to detect involvement of a chest (thoracic) artery. Ocular pneumoplethysmography can help make the diagnosis of temporal arteritis. Multiple biopsies may be indicated if initial findings are negative, but the suspicion for this diagnosis remains high.
Treatment team
The condition can be diagnosed by a primary care provider. Consultations may be indicated with an ophthalmologist (if there are visual complications). Generally an internist or rheumatologist directs the general care for systemic symptoms.
Treatment
Oral steroids are effective treatment for TA. Treatment is critical and important to avoid vision loss. Treatment should be initiated based on clinical suspicion and should not be delayed for biopsy results. The use of steroid or prednisone can be initially given at a dose of 60 to 100 mg per day. The dose can be tapered down in an individualized manner at a rate of approximately 10% per week, while concurrently taking into account symptomatic state and lab result improvement.
Recovery and rehabilitation
Most patients can be treated on an outpatient basis, with steroids, and symptoms usually begin to resolve within one to three days. Patients may require oral steroid medication for up to one year, depending on individual response. Nonsteroidal anti-inflammatory drugs may provide some pain relief.
Clinical trials
A clinical trial sponsored by the Cleveland Clinic Foundation Hospital and the National Institute of Health concerning the treatment of TA. The study is a multi-institutional project which includes medical centers within the United States and in several countries overseas. Full details can be obtained from the website: <http://www.clinicaltrials.gov>.
Prognosis
The condition is self-limiting and can last up to two years. Treatment with corticosteroids produces relief of symptoms and can help with visual impairment.
Special concerns
A diagnosis of TA can be missed. The disorder should be suspected in older patients with a high erythrocyte sedimentation rate (ESR), even if other evidence is absent.
Resources
BOOKS
Goetz, Christopher G., et al., eds. Textbook of Clinical Neurology. 1st ed. Philadelphia: W. B. Saunders Company, 1999.
Goldman, Lee, et al. Cecil's Textbook of Medicine. 21st ed. Philadelphia: W. B. Saunders Company, 2000.
Noble, John., et al., eds. Textbook of Primary Care Medicine. 3rd ed. St. Louis: Mosby, Inc., 2001.
WEBSITES
American Heart Association. <http://www.americanheart.org>.
ORGANIZATIONS
National Heart, Lung, and Blood Institute, Building 31, Room 5A52. 31 Center Drive MSC 2486, Bethesda, MD 20892. (301) 592-8573; Fax: (301) 592-8563. nhlbiinfo@nhlbi.nih.gov. <http://www.nhlbi.nih.gov>.
