What are the symptoms of carotid stenosis?

Symptoms of Carotid Stenosis

Carotid stenosis typically presents with transient ischemic attacks (TIAs) lasting less than 24 hours or ischemic strokes with symptoms lasting more than 24 hours, with the most characteristic manifestation being amaurosis fugax (transient monocular blindness). 1

Primary Manifestations

• TIAs present as focal neurologic deficits lasting less than 24 hours, while ischemic stroke involves symptoms lasting more than 24 hours 1
• Motor deficits are common symptoms, including isolated paresis of the hand, arm, arm and face, or more rarely, the leg 1
• Sensory deficits, such as numbness or tingling affecting the contralateral side of the body to the affected carotid artery 1
• Amaurosis fugax (transient monocular blindness) is a characteristic symptom caused by temporary reduction of blood flow to the eye 1, 2
• Blurred vision and confusion may be present, especially in early stages 3

Advanced Manifestations

• Retinal emboli may be detected during eye examinations, even in otherwise asymptomatic patients 1, 2
• Limb-shaking TIA, characterized by positive motor phenomena associated with hemodynamic impairment 1
• Low-flow TIA, involving transient cerebral hypoperfusion due to severe stenosis 1
• Superior altitudinal visual field defects may occur due to retinal arterial emboli 2
• Severe cases may progress to paralysis due to stroke 3

Risk Factors and Clinical Correlations

• Carotid stenosis >50% represents the inflection point at which blood flow velocity accelerates above normal 1
• Carotid stenosis >50% is the strongest predictor of new vascular events after TIA 1
• Patients with TIA caused by carotid stenosis have significantly elevated stroke risk—up to 20% in the first 3 months in older studies, and approximately 6% in the first year according to more recent data 1
• Risk factors include hypertension, hyperlipidemia, diabetes mellitus, and cigarette smoking 1, 2
• Men tend to have larger plaques with more calcifications, lipid-rich necrotic cores, and intra-plaque hemorrhage compared to women 1

Important Clinical Considerations

• The presentation of carotid stenosis is often insidious, with symptoms typically manifesting only at severe stenosis 3
• Patients with retinal arterial emboli are at increased risk for stroke and vascular death 2
• Individuals with atherosclerotic carotid artery stenosis can have a prevalence of atherosclerotic coronary artery disease as high as 50-75% 4
• High-risk carotid plaques are characterized by large lipid cores, intraplaque hemorrhage, thin fibrous caps, and surface ulcerations or fissures 4
• Symptomatic carotid artery stenosis is defined as an acute neurologic deficit occurring in the last 6 months that is ipsilateral to an extracranial carotid artery with at least 50% stenosis 5

Common Pitfalls and Caveats

• Symptoms may be mistaken for other neurological conditions, so imaging confirmation is essential 1, 4
• Not all patients with carotid stenosis are symptomatic; asymptomatic disease has a different natural history and management approach 6
• Dimming of vision on extreme head turning can be a subtle presentation of carotid stenosis that might be overlooked 2
• Patients may present with monocular vision loss as their initial and only symptom 2
• Differentiation between symptomatic and asymptomatic disease is critical as the natural history and management differ markedly 6