Giant
cell arteritis (GCA) / Temporal arteritis
- aka
Horton’s disease
- Systemic
granulomatous vasculitis involving medium to large arteries
-
Predilection for vessels of the head and neck, in particular branches of
external carotid artery and ophthalmic artery
- May
extend to include the aorta, coronary, carotid and vertebral arteries, as well
as subclavian, axillary, femoral and popliteal vessels
Epidemiology
- Most
commonly occurs in patients >70 years old (yo), very rarely if <50 yo
-
Prevalence increases with age
>50
yo 10-200/100,000
>80
yo 50-1000/100,000
-
Primarily in caucasians, lower incidence in asian and black population
- Female
> male 2-4:1
Clinical
presentation
- Headache (70-90%)
-
often unilateral in area of superficial temporal artery but may be bilateral or
holocephalic
-
typically severe and throbbing but may be sharp, dull or burning
- Visual
loss
-
Onset over hours to days of unilateral visual loss (secondary to optic
nerve/retinal ischemia; form of anterior ischemic optic neuropathy)
-
20% experience recurrent transient monocular blindness (amaurosis fugax) as
initial presentation
-
May affect vision in opposite eye within 1-21 days if untreated (up to 75%)
-
Diplopia
-
secondary to ischemia of CN III, IV, VI (single or multiple) or of extraocular
muscles directly
- usually
precedes visual loss, rarely develops after onset of visual loss
-
50% of patients presenting with diplopia will develop visual loss in affected
eye
- Tender
scalp overlying superficial temporal artery
e.g. tender scalp if brushing hair
- Jaw
and/or tongue claudication (40-60%)
- Pain in jaw or tongue after
eating/chewing or talking
- Most specific sign for temporal
arteritis (positive likelihood ratio 4.2)
-
Systemic symptoms including: anorexia, malaise, weight loss, low grade fever
-
Polymyalgia rheumatica (PMR) often precedes onset of GCA (25-50%)
-
proximal muscle and periarticular pain, morning stiffness, fever, anorexia, and
weight loss
- Limb
claudication
- TIA or
stroke, usually anterior circulation but may occur in posterior circulation
(4%)
- secondary
to involvement of intracranial vessels or their suppliers (e.g. vertebral
arteries)
Key
aspects of clinical examination
- low
grade fever may be present
- tender,
nodular, swollen, erythematous superficial temporal artery with decreased or
absent pulse
- inspect
scalp and tongue for ischemic / necrotic areas (rare)
- visual
acuity usually severely affected
-
relative afferent pupillary defect present if visual acuity severely affected
- visual
field defect tends to be altitudinal if subtotal
-
funduscopy
-
swollen pale optic disc, often with peripapillary splinter hemorrhages and
cotton wool spots
-
10% have central retinal artery occlusion with cherry red spot
- assess
extraocular movements carefully
- Horner’s syndrome may be seen
Investigations
Laboratory
-
Erythrocyte sedimentation rate (ESR):
- Elevated to 60-120 mm per hour
- Often >100 mm per hour
- Normal in 1-2%
-
C-reactive protein (CRP):
- rises and falls earlier than ESR
-
Mild normochromic normo-/micro-cytic anemia, leukocytosis and thrombocytosis
-
Mildly elevated liver transaminases (50%)
Duplex
ultrasonography
- demonstrates
stenosis and occlusion of temporal artery segments
-
characteristic dark hypoechoic halo around affected vessel
-
has not yet replaced the need for temporal artery biopsy
- if
classic findings on ultrasound with typical history and high ESR…probably don’t
need to perform temporal artery biopsy (NEJM 1997; 337: 1336-42)
Temporal
artery biospy
-
Overall, in patients in which there is a clinical suspicion of GCA, ~40% of
biopsies are positive
-
The presence of jaw claudication or diplopia on history or an enlarged, tender,
pulseless temporal artery on exam increases the likelihood of a positive biopsy
-
Biopsy is taken from the superficial temporal artery ipsilateral to the visual
loss
-
Positive biospy reveals: segments of chronic inflammation most intense
in the media, with multinucleated giant cells, monocytes and
eosinophils, as well as polymorphonuclear leukocytes. Disruption of internal
elastic lamina. Arterial occlusion and necrosis are often seen at sites
of active inflammation.
- Skip
areas: inflammation of affected vessels is multifocal and not diffuse,
and therefore, there may be skip areas where there is minimal or no
inflammation.
-
Perform contralateral biopsy if initial biopsy is negative and clinical
suspicion remains high
-
Corticosteroid treatment does not significantly affect yield if initiated
within 2-3 days of biopsy; yield decreases thereafter
American
College of Rheumatology diagnostic criteria
Presence
of 3 of the 5 criteria below results in a sensitivity of 93.5% and specificity
of 91.2%:
(1) age
> 50 years
(2) new
onset of localized headache
(3)
temporal artery tenderness or decreased temporal arterial pulse
(4)
increased ESR (>50 mm/h)
(5) arterial
biopsy showing necrotizing arteritis characterized by a predominance of
mononuclear cell infiltrates or a granulomatous process.
Treatment
Corticosteroids
- initiate
immediately if suspect GCA and refer to ophthalmology for TA biopsy
-
60-80 mg PO prednisone daily if no visual loss on examination
-
100-120 mg daily if visual loss is present
-
consider 1 g IV methylprednisolone as initial dose (followed by 100-120 mg
daily PO prednisone) if onset of visual loss within 24-48 h or rapidly
progressive visual loss in both eyes,
-
maintain dose of steroid until systemic complaints disappear and either CRP/ESR
normalize or CRP/ESR demonstrate a significant trend towards normalization (3-7
days)
-
will require at least 60-80 mg prednisone daily for first month
-
gradually reduce dose over at least 6 months to 1 year by decreasing
5-10 mg per week
-
Monitor ESR frequently while tapering steroid
- if
systemic symptoms recur increase dose by 10 mg/d until resolved
- if
neurological symptoms recur, reinstitue high dose treatment
-
Monitor for side effects of prolonged steroid use ie. osteoporosis,
hypertension, infections, worsening of diabetic control, avascular necrosis of
hip, peptic ulcers etc.
Other
immunosuppressants
- there
is some evidence that addition of methotrexate allows steroid-sparing and
reduces relapses with steroid reduction (Arch Int Med 2001; 134:106-14)
Prognosis
-
Self-limited disease that persists for months to up to 3 years (rarely longer)
- Remission
usually occurs within 1 year, but rarely before 6 months
- If
untreated, up to 75% of patients will lose vision in opposite eye within 1-21
days, usually within 1 week
- Systemic
complaints often resolve within 72 hours of high dose steroid therapy
- Visual
loss rarely recovers
- Mortality
is the same as for age-matched controls
- Major
late complication is aortic aneurysm / dissection, especially thoracic aorta (18%;
median time 5 years)
References”
- AAN
Annual CD
-
eMedicine
- NICP.
Bradley, Daroff, Fenichel and Marsden
- Smetana
GW, Shmerling RH. Does this patient have temporal arteritis? JAMA. 2002 Jan
2;287(1):92-101.
- Arch
Int Med 2001; 134:106-14
- NEJM
1997; 337: 1336-42
Last
update: February
2004
Reviewed
by: pending review
Neurological
Medicine Pocketbook
© 2003-2004
UWO Neurology Residents
http://www.uwo.ca/cns/resident
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Rights Reserved