What is giant cell arteritis and what is the risk of stroke associated with it?
Giant cell arteritis is a rare vasculitis (incidence rate, 9 16 per 100000 per year in individuals 50 years of age) that can cause stroke in 7% of confirmed cases.672 674 Patients with symptoms of giant cell arteritis should be treated urgently, and high-dose steroids should be initiated quickly within the first 24 hours after symptoms onset to reduce the risk of permanent blindness and to increase the chance of visual recovery.675 678 Practitioners should keep a high index of clinical suspicion to consider giant cell arteritis in the differential. Laboratory testing such as elevated sedimentation rate or C-reactive protein and a compatible semiology may be the only available elements to make a decision to initiate treatment. If available, ultrasound finding of a halo sign surrounding a temporal artery may be helpful in diagnosis giant cell arteries.680,681 Biopsy confirmation should not be imperative to initiate treatment in cases in which giant cell arteritis seems to be the most likely diagnosis.