Temporal arteritis
Encyclopedia
Giant-cell arteritis or Horton disease is an inflammatory
disease of blood vessel
s most commonly involving large and medium arteries
of the head. It is a form of vasculitis
.
The name (giant cell
arteritis) reflects the type of inflammatory cell involved as seen on a biopsy
.
The terms "giant-cell arteritis" and "temporal arteritis" are sometimes used interchangeably, because of the frequent involvement of the temporal artery. However, it can involve other large vessels (such as the aorta
in "giant-cell aortitis"). Giant-cell arteritis of the temporal artery is referred to as "temporal arteritis," and is also known as "Cranial arteritis" and "Horton's disease."
Patients present with:
The inflammation may affect blood supply to the eye
and blurred vision or sudden blindness
may occur. In 76% of cases involving the eye, the ophthalmic artery
is involved causing arteritic anterior ischemic optic neuropathy
. Loss of vision in both eyes may occur very abruptly and this disease is therefore a medical emergency
.
(PMR), which is characterized by sudden onset of pain and stiffness in muscles (pelvis
, shoulder
) of the body and is seen in the elderly. GCA and PMR are so closely linked that they are often considered to be different manifestations of the same disease process. Other diseases related with temporal arteritis are systemic lupus erythematosus
, rheumatoid arthritis
and severe infection
s.
for diagnosing temporal arteritis is biopsy
, which involves removing a small part of the vessel and examining it microscopically
for giant cell
s infiltrating the tissue. Since the blood vessel
s are involved in a patchy pattern, there may be unaffected areas on the vessel and the biopsy might have been taken from these parts. Unilateral biopsy of a 1.5–3 cm length is 85-90% sensitive (1 cm is the minimum). So, a negative result does not definitely rule out the diagnosis. Thus, currently biopsy is only considered confirmatory for the clinical diagnosis, or one of diagnostic criteria.
yields a halo sign
.
Contrast enhanced brain MRI and CT is generally negative in this disorder.
Recent studies have shown that 3T MRI using super high resolution imaging and contrast injection can non-invasively diagnose this disorder with high specificity and sensitivity.
s, typically high-dose prednisone
(40–60 mg. once daily), must be started as soon as the diagnosis is suspected (even before the diagnosis is confirmed by biopsy) to prevent irreversible blindness secondary to ophthalmic artery
occlusion. Steroids do not prevent the diagnosis from later being confirmed by biopsy, although certain changes in the histology may be observed towards the end of the first week of treatment and are more difficult to identify after a couple of months. The dose of prednisone
is lowered after 2–4 weeks, and slowly tapered over 9–12 months. Oral steroids are at least as effective as intravenous steroids, except in the treatment of acute visual loss where intravenous steroids appear to offer significant benefit over oral steroids
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
disease of blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
s most commonly involving large and medium arteries
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
of the head. It is a form of vasculitis
Vasculitis
Vasculitis refers to a heterogeneous group of disorders that are characterized by inflammatory destruction of blood vessels. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis...
.
The name (giant cell
Giant cell
A giant cell is a mass formed by the union of several distinct cells . It can arise in response to an infection or foreign body.Types include:* foreign-body giant cell* Langhans giant cell* Touton giant cells...
arteritis) reflects the type of inflammatory cell involved as seen on a biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
.
The terms "giant-cell arteritis" and "temporal arteritis" are sometimes used interchangeably, because of the frequent involvement of the temporal artery. However, it can involve other large vessels (such as the aorta
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
in "giant-cell aortitis"). Giant-cell arteritis of the temporal artery is referred to as "temporal arteritis," and is also known as "Cranial arteritis" and "Horton's disease."
Signs and symptoms
It is more common in males than females by a ratio of 2:1. The mean age of onset is > 50 years, and it is rare in those less than 50 years of age.Patients present with:
- bruitBruitBruit is the term for the unusual sound that blood makes when it rushes past an obstruction in an artery when the sound is auscultated with the bell portion of a stethoscope.The term "bruit" simply refers to the sound...
s - feverFeverFever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
- headacheHeadacheA headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
- tenderness and sensitivity on the scalpScalpThe scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly.-Layers:It is usually described as having five layers, which can conveniently be remembered as a mnemonic:...
- jawJawThe jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...
claudicationClaudicationClaudication, literally 'limping' , is a medical term usually referring to impairment in walking, or pain, discomfort or tiredness in the legs that occurs during walking and is relieved by rest. The perceived level of pain from claudication can be mild to extremely severe. Claudication is most...
(pain in jaw when chewing) - tongueTongueThe tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...
claudicationClaudicationClaudication, literally 'limping' , is a medical term usually referring to impairment in walking, or pain, discomfort or tiredness in the legs that occurs during walking and is relieved by rest. The perceived level of pain from claudication can be mild to extremely severe. Claudication is most...
(pain in tongue when chewing) and necrosisNecrosisNecrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death... - reduced visual acuityVisual acuityVisual acuity is acuteness or clearness of vision, which is dependent on the sharpness of the retinal focus within the eye and the sensitivity of the interpretative faculty of the brain....
(blurred vision) - acute visual loss (sudden blindness)
- diplopiaDiplopiaDiplopia, commonly known as double vision, is the simultaneous perception of two images of a single object that may be displaced horizontally, vertically, or diagonally in relation to each other...
(double vision) - acute tinnitusTinnitusTinnitus |ringing]]") is the perception of sound within the human ear in the absence of corresponding external sound.Tinnitus is not a disease, but a symptom that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period , ear...
(ringing in the ears)
The inflammation may affect blood supply to the eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
and blurred vision or sudden blindness
Blindness
Blindness is the condition of lacking visual perception due to physiological or neurological factors.Various scales have been developed to describe the extent of vision loss and define blindness...
may occur. In 76% of cases involving the eye, the ophthalmic artery
Ophthalmic artery
The ophthalmic artery is the first branch of the internal carotid artery distal to the cavernous sinus. Branches of the OA supply all the structures in the orbit as well as some structures in the nose, face and meninges...
is involved causing arteritic anterior ischemic optic neuropathy
Arteritic anterior ischemic optic neuropathy
Arteritic anterior ischemic optic neuropathy is the cause of vision loss that occurs in temporal arteritis . Temporal arteritis is an inflammatory disease of medium-sized blood vessels that happens especially with advancing age. AAION occurs in about 15-20 percent of patients with temporal arteritis...
. Loss of vision in both eyes may occur very abruptly and this disease is therefore a medical emergency
Medical emergency
A medical emergency is an injury or illness that is acute and poses an immediate risk to a person's life or long term health. These emergencies may require assistance from another person, who should ideally be suitably qualified to do so, although some of these emergencies can be dealt with by the...
.
Associated conditions
The disorder may coexist (in one quarter of cases) with polymyalgia rheumaticaPolymyalgia rheumatica
Polymyalgia rheumatica , abbreviated as PMR, is a syndrome with pain or stiffness, usually in the neck, shoulders, and hips. The pain can be very sudden, or can occur gradually over a period of time...
(PMR), which is characterized by sudden onset of pain and stiffness in muscles (pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
, shoulder
Shoulder
The human shoulder is made up of three bones: the clavicle , the scapula , and the humerus as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder make up the shoulder joints. The major joint of the shoulder is the glenohumeral joint, which...
) of the body and is seen in the elderly. GCA and PMR are so closely linked that they are often considered to be different manifestations of the same disease process. Other diseases related with temporal arteritis are systemic lupus erythematosus
Lupus erythematosus
Lupus erythematosus is a category for a collection of diseases with similar underlying problems with immunity . Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs...
, rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
and severe infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
s.
Physical exam
- Palpation of the head reveals prominent temporal arteriesSuperficial temporal arteryIn human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it bifurcates into the superficial temporal artery and maxillary artery....
with or without pulsation. - The temporal areaTemporal boneThe temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebrum.The temporal bone supports that part of the face known as the temple.-Parts:The temporal bone consists of four parts:* Squama temporalis...
may be tender. - Decreased pulses may be found throughout the body.
- Evidence of ischemiaIschemiaIn medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
may be noted on fundal exam.
Laboratory tests
- LFTs, liver function testsLiver function testsLiver function tests , are groups of clinical biochemistry laboratory blood assays designed to give information about the state of a patient's liver. The parameters measured include PT/INR, aPTT, albumin, billirubin and others...
, are abnormal particularly raised ALP- alkaline phosphatase - Erythrocyte sedimentation rateErythrocyte sedimentation rateThe erythrocyte sedimentation rate , also called a sedimentation rate or Biernacki Reaction, is the rate at which red blood cells sediment in a period of 1 hour...
, an inflammatory marker, >60 mm/hour (normal 10–40 mm/hour), but may be normal in approximately 20% of cases. - C-reactive proteinC-reactive proteinC-reactive protein is a protein found in the blood, the levels of which rise in response to inflammation...
, another inflammatory marker, is also commonly elevated. - Platelets may also be elevated.
Biopsy
The gold standardGold standard (test)
In medicine and statistics, gold standard test refers to a diagnostic test or benchmark that is the best available under reasonable conditions. It does not have to be necessarily the best possible test for the condition in absolute terms...
for diagnosing temporal arteritis is biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
, which involves removing a small part of the vessel and examining it microscopically
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
for giant cell
Giant cell
A giant cell is a mass formed by the union of several distinct cells . It can arise in response to an infection or foreign body.Types include:* foreign-body giant cell* Langhans giant cell* Touton giant cells...
s infiltrating the tissue. Since the blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
s are involved in a patchy pattern, there may be unaffected areas on the vessel and the biopsy might have been taken from these parts. Unilateral biopsy of a 1.5–3 cm length is 85-90% sensitive (1 cm is the minimum). So, a negative result does not definitely rule out the diagnosis. Thus, currently biopsy is only considered confirmatory for the clinical diagnosis, or one of diagnostic criteria.
Imaging studies
Radiological examination of the temporal artery with ultrasoundUltrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
yields a halo sign
Halo sign
In radiology, the halo sign is a finding on ultrasound that suggests the diagnosis of temporal arteritis. The standard diagnostic test for temporal arteritis is biopsy; however, ultrasound and MRI show promise for replacing it....
.
Contrast enhanced brain MRI and CT is generally negative in this disorder.
Recent studies have shown that 3T MRI using super high resolution imaging and contrast injection can non-invasively diagnose this disorder with high specificity and sensitivity.
Treatment
CorticosteroidCorticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
s, typically high-dose prednisone
Prednisone
Prednisone is a synthetic corticosteroid drug that is particularly effective as an immunosuppressant drug. It is used to treat certain inflammatory diseases and some types of cancer, but has significant adverse effects...
(40–60 mg. once daily), must be started as soon as the diagnosis is suspected (even before the diagnosis is confirmed by biopsy) to prevent irreversible blindness secondary to ophthalmic artery
Ophthalmic artery
The ophthalmic artery is the first branch of the internal carotid artery distal to the cavernous sinus. Branches of the OA supply all the structures in the orbit as well as some structures in the nose, face and meninges...
occlusion. Steroids do not prevent the diagnosis from later being confirmed by biopsy, although certain changes in the histology may be observed towards the end of the first week of treatment and are more difficult to identify after a couple of months. The dose of prednisone
Prednisone
Prednisone is a synthetic corticosteroid drug that is particularly effective as an immunosuppressant drug. It is used to treat certain inflammatory diseases and some types of cancer, but has significant adverse effects...
is lowered after 2–4 weeks, and slowly tapered over 9–12 months. Oral steroids are at least as effective as intravenous steroids, except in the treatment of acute visual loss where intravenous steroids appear to offer significant benefit over oral steroids
External links
- Giant Cell Arteritis article at University of IowaUniversity of IowaThe University of Iowa is a public state-supported research university located in Iowa City, Iowa, United States. It is the oldest public university in the state. The university is organized into eleven colleges granting undergraduate, graduate, and professional degrees...
- Polymyalgia rheumatica article from National Institute of Arthritis and Musculoskeletal and Skin DiseasesNational Institute of Arthritis and Musculoskeletal and Skin DiseasesThe National Institute of Arthritis and Musculoskeletal and Skin Diseases, or NIAMS, is an institute of the National Institutes of Health, an agency of the United States Department of Health and Human Services...
- Temporal (Giant Cell) Arteritis - PrimeHealthChannel.com
- PMRGCAuk - UK charity offering support, raising awareness, promoting research