What are the symptoms of carotid artery stenosis?

Symptoms of Carotid Artery Stenosis

Carotid artery stenosis can present with a spectrum of neurological symptoms ranging from focal deficits to complete stroke, or remain entirely asymptomatic until a catastrophic event occurs. 1

Primary Symptomatic Manifestations

Symptoms of carotid artery stenosis typically arise from two main mechanisms:

1. Athero-thromboembolism (most common): Plaque inflammation and disruption with subsequent embolism of thrombus or plaque debris 1

2. Hemodynamic impairment: Cerebral ischemia from flow reduction in high-grade stenosis or occlusion 1

Focal Neurological Symptoms

• Hemispheric (cortical) symptoms - contralateral to the affected carotid artery: 1

  • Motor deficits: Isolated paresis/weakness of hand, arm, face (rarely leg)
  • Sensory deficits: Numbness or tingling
  • Language disturbances: Aphasia (if dominant hemisphere, usually left, is affected)
  • Cognitive symptoms: Hemineglect (if non-dominant hemisphere, usually right, is affected)

• Ocular symptoms: 1

  • Amaurosis fugax (temporary monocular blindness)
  • Permanent partial or total blindness in the ipsilateral eye

• Other manifestations: 1

  • Hemianopsia (visual field defect - when optic tract is involved)
  • "Limb-shaking TIA" - positive motor phenomena associated with hemodynamic impairment
  • "Stuttering stroke" - symptom progression over hours to days due to thrombus propagation

Duration and Classification

• Transient Ischemic Attack (TIA): Focal neurologic deficits lasting <24 hours (typically <60 minutes) 1
• Ischemic Stroke: Symptoms lasting >24 hours 1

Risk Stratification

Patients with symptomatic carotid stenosis are at significantly higher risk for recurrent events:

• Historical data showed up to 20% risk of stroke in first 3 months after TIA 1
• More recent data indicates approximately 6% risk in the first year 1
• Carotid stenosis >50% is the strongest predictor of new vascular events after TIA 1

Asymptomatic Carotid Stenosis

Many patients with carotid stenosis remain asymptomatic until a stroke occurs. However, certain findings may indicate higher risk: 1, 2

• Silent brain infarction on imaging
• Retinal emboli detected during screening
• Progression of stenosis severity on serial imaging
• Vulnerable plaque characteristics (intra-plaque hemorrhage, lipid-rich necrotic core, ulceration)

Severity-Related Symptoms

The severity of symptoms correlates with:

• Degree of stenosis (especially >70%)
• Plaque morphology and vulnerability
• Efficacy of collateral circulation
• Speed of occlusion development

Clinical Pearls and Pitfalls

• Important caveat: The absence of symptoms does not indicate low risk - asymptomatic carotid stenosis can progress silently until a catastrophic event 1, 3

• Diagnostic challenge: Neurological evaluation is essential as it may be difficult to determine whether symptoms are related to carotid stenosis 1

• Risk factor awareness: Patients with multiple risk factors (hypertension, diabetes, smoking, dyslipidemia) and disease progression have significantly higher stroke risk, even with moderate stenosis 3

• Monitoring recommendation: Regular duplex ultrasound surveillance is crucial for detecting disease progression before stroke occurs, as progression was detected in 79% of patients before artery occlusion or stroke 3

• Severity spectrum: Internal carotid artery occlusion can present with varying symptom severity from clinically silent to catastrophic, depending on collateral circulation 1

Regular imaging surveillance with duplex ultrasound and aggressive management of modifiable risk factors are essential components of care for all patients with carotid stenosis, regardless of symptom status.