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Essentials of Diagnosis
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General Considerations
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In patients aged 50 years or older with central retinal artery occlusion, consider giant cell arteritis
Carotid and cardiac sources of emboli must be sought so that treatment can be given to reduce the risk of stroke
In young patients, causes include
Internal carotid artery dissection should be considered when there is neck pain or a recent history of neck trauma
In all patients, consider
Diabetes mellitus
Hyperlipidemia
Systemic hypertension
Giant cell arteritis should be considered in cases of central retinal artery occlusion without visible emboli
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Central retinal artery occlusion
Presents as sudden profound monocular visual loss
Visual acuity is usually reduced to counting fingers or worse
Visual field is restricted to an island of vision in the temporal field
Branch retinal artery occlusion
May also present with sudden loss of vision if the fovea is involved, but more commonly sudden loss of a discrete area in visual field in one eye is the presenting complaint
Fundus signs of retinal swelling and adjacent cotton-wool spots are limited to the area of retina supplied by the occluded artery
Identify risk factors for a cardiac source of emboli including arrhythmia, particularly atrial fibrillation, and cardiac valvular disease; and check the blood pressure
Clinical features of giant cell arteritis include
Jaw claudication (which is very specific)
Headache
Scalp tenderness
General malaise
Weight loss
Polymyalgia rheumatica: shoulder and hip girdle pain
Tenderness or thickening of, or absence of pulse in, the superficial temporal arteries
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Test for diabetes (fasting serum glucose, hemoglobin A1C) and hyperlipidemia (fasting serum cholesterol, HDL cholesterol, LDL cholesterol, triglycerides) in all patients
Erythrocyte sedimentation rate and C-reactive protein are usually markedly elevated in giant cell arteritis but one or both may be normal
Consider testing for other types of vasculitis (eg, antinuclear antibody, rheumatoid factor, anticytoplasmic neutrophil antibody)
In younger patients, consider tests for congenital or acquired hypercoagulable states (thrombophilia)
Antiphospholipid antibody syndrome (lupus anticoagulant)
Activated protein C resistance/Factor V Leiden
Protein C, protein S deficiency
Antithrombin deficiency
Hyperprothrombinemia (G20210A prothrombin gene mutation)
Increased Factor VIII activity
Hyperhomocysteinemia
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Obtain duplex ultrasonography of the carotid arteries, ECG, and echocardiography (with transesophageal echocardiography, if necessary), to identify carotid and cardiac sources of emboli
When indicated, obtain CT or MR angiography studies for internal carotid artery dissection
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