Snapshot A 60-year-old man presents with a visual disturbance that occurred one day ago. He reports that he experienced a “curtain coming down” over his left eye that lasted a few minutes. His past medical history includes long-standing type 2 diabetes mellitus, hypertension, coronary artery disease, and a 20 pack-year smoking history. On physical exam, he has bilateral carotid bruits. An ultrasound duplex of his carotids shows bilateral stenosis with 40% on the right and 75% on the left. Introduction Clinical definition carotid artery narrowing, or stenosis, caused by atherosclerotic plaques Associated conditions peripheral artery disease coronary artery disease Epidemiology Demographics male > female Risk factors family history hyperlipidemia smoking hypertension diabetes older age Etiology Atherosclerosis Pathogenesis build up of atherosclerotic plaques in the carotid arteries causes narrowing of the lumen free cholesterol creates a necrotic core, contained by a weak fibrous cap enlargement of the necrotic core can disrupt the fibrous cap and cause thrombosis or embolization Presentation Symptoms may be asymptomatic if symptomatic, usually presents as transient ischemic attack or stroke transient visual disturbance (amaurosis fugax) unilateral muscle weakness or paresthesia dizziness tinnitus aphasia Physical exam carotid bruit (typically present if there’s 60-70% stenosis) motor or sensory deficits Imaging Duplex Doppler ultrasound indications best initial test findings level of stenosis > 50% is moderate > 70% is severe Angiography (magnetic resonance or computed tomography) indications ultrasound unavailable or findings are unclear DIAGNOSIS Making the diagnosis based on clinical presentation and imaging Differential Temporal arteritis distinguishing factors may also present with amaurosis fugax and carotid bruit however, may present with other symptoms such as headache or jaw claudication ↑ inflammatory markers no carotid stenosis is seen on ultrasound Treatment Management approach screening for asymptomatic patients is not recommended all patients should receive optimal therapy for the underlying cardiovascular disease, such as hypertension or hyperlipidemia Conservative smoking cessation indication for all patients Medical anti-platelet therapy indication symptomatic patients drugs clopidogrel aspirin plus dipyridamole statins indication for all patients Operative carotid artery revascularization indication stenosis > 70% post-transient ischemic attack or stroke surgeries carotid endarterectomy (CEA) first-line for patients who can tolerate surgery carotid artery stenting for patients unable to tolerate CEA Complications Neurological sequelae central retinal artery occlusion transient ischemic attack stroke nerve injury facial nerve specifically the marginal mandibular branch hyopglossal nerve recurrent laryngeal nerve glossopharyngeal nerve specifically nerve of Herin branch sympathetic nerve Prognosis ↑ Survival with appropriate treatment