What are the symptoms of carotid stenosis?

Symptoms of Carotid Stenosis

Carotid stenosis most commonly presents with transient ischemic attack (TIA), stroke, or amaurosis fugax (transient monocular blindness), though many patients remain asymptomatic until severe stenosis develops. 1

Neurological Manifestations

Transient Ischemic Attack (TIA)

• TIA presents as focal neurologic deficits lasting less than 24 hours, distinguishing it from stroke which persists beyond 24 hours 1
• Patients with TIA from carotid stenosis face approximately 6% stroke risk in the first year, with carotid stenosis >50% being the strongest predictor of new vascular events 1
• Motor deficits are common and include isolated paresis of the hand, arm, arm and face together, or less frequently the leg 1
• Sensory deficits manifest as numbness or tingling on the same side of the body, contralateral to the affected carotid artery 1

Stroke Presentation

• Ischemic stroke from carotid stenosis involves neurologic symptoms persisting more than 24 hours 1
• Hemispheric (cortical) ischemia can occur, producing more extensive neurological deficits 2
• The presentation is often insidious, with symptoms exhibiting predominantly at severe stenosis stages 3

Visual Symptoms

Amaurosis Fugax

• Amaurosis fugax (transient monocular blindness) results from temporary reduction of blood flow to the eye and is a classic symptom of carotid stenosis 1, 2
• Patients may describe dimming of vision, superior or inferior altitudinal visual field defects, or complete transient vision loss 4
• Retinal emboli may be detected during eye examinations, even in otherwise asymptomatic patients 1
• Vision loss can occur with extreme head turning in some cases 4

Specialized Presentations

Hemodynamic Symptoms

• Limb-shaking TIA, characterized by positive motor phenomena, occurs with hemodynamic impairment from severe stenosis 1
• Low-flow TIA involves transient cerebral hypoperfusion due to critically severe stenosis 1

Non-Specific Symptoms

• Blurred vision and confusion can occur with milder presentations 3
• Hearing changes may be part of the spectrum of non-specific neurological symptoms 2

Asymptomatic Presentation

A critical pitfall is that many patients with significant carotid stenosis remain completely asymptomatic until a catastrophic event occurs 3, 5. This underscores the importance of screening high-risk populations, including those with:

• Symptomatic peripheral arterial disease, coronary artery disease, or atherosclerotic aortic aneurysm 6
• Multiple atherosclerotic risk factors (hypertension, diabetes, hyperlipidemia, smoking) 1, 6

Risk Stratification Factors

• The risk of subsequent stroke after TIA or amaurosis fugax correlates with other vascular risk factors including hypertension, hypercholesterolemia, diabetes, and cigarette smoking 1
• Men tend to have larger plaques with more calcifications, lipid-rich necrotic cores, and intra-plaque hemorrhage compared to women 1
• Carotid stenosis >50% represents the inflection point where blood flow velocity accelerates above normal due to atherosclerotic plaque 1

Clinical Caveat

Patients presenting with any monocular vision loss, especially those over 50 years old, must be evaluated for carotid artery disease as a differential diagnosis 4. Patients who exhibit retinal arterial emboli are at increased risk for stroke and vascular death 4.