From the Guidelines
Carotid artery occlusion typically presents with sudden onset of contralateral hemiparesis, contralateral hemisensory loss, and ipsilateral amaurosis fugax, among other symptoms, as a result of reduced blood flow to the brain, causing ischemia in the territory supplied by the middle cerebral artery. The clinical features of carotid artery occlusion can vary depending on which cerebral hemisphere is affected, with symptoms including dysphasia or aphasia, facial droop, dysarthria, and altered mental status 1. According to the 2011 ASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline, carotid ultrasonography, CTA, and MRA can provide the information needed to guide the choice of medical, endovascular, or surgical treatment in most cases 1.
Key Clinical Features
- Sudden onset of contralateral hemiparesis (weakness on the opposite side of the body from the occluded artery)
- Contralateral hemisensory loss
- Ipsilateral amaurosis fugax (temporary vision loss in the eye on the same side as the occlusion)
- Dysphasia or aphasia (particularly with left carotid occlusion)
- Facial droop
- Dysarthria
- Altered mental status
- Headache, particularly in the frontal or periorbital region on the affected side
The severity of symptoms depends on the degree of occlusion and the adequacy of collateral circulation, with complete occlusion without sufficient collaterals typically causing more severe deficits, while partial occlusion or good collateral circulation may result in milder or transient symptoms 1. Carotid bruits may be auscultated over the carotid artery in some patients, though their absence doesn't rule out significant stenosis. These symptoms occur because carotid artery occlusion reduces blood flow to the brain, causing ischemia in the territory supplied by the middle cerebral artery, which controls motor and sensory functions of the face and upper limbs, as well as language centers in the dominant hemisphere.
Diagnostic Evaluation
The guideline recommends that duplex carotid ultrasonography might be considered for patients with nonspecific neurological symptoms when cerebral ischemia is a plausible cause, and that catheter-based contrast angiography may be considered to determine whether the arterial lumen is sufficiently patent to permit carotid revascularization when complete carotid arterial occlusion is suggested by duplex ultrasonography, MRA, or CTA in patients with retinal or hemispheric neurological symptoms of suspected ischemic origin 1. Accurate assessment of the severity of arterial stenosis is essential to the selection of appropriate patients for surgical or endovascular intervention, and imaging of the extracranial carotid arteries should be performed whenever cerebral ischemia is a suspected mechanism of neurological symptoms in a viable patient 1.
From the Research
Clinical Features of Carotid Artery Occlusion
The clinical presentation of carotid artery occlusion can vary significantly, ranging from asymptomatic occlusion to severe ischemic strokes 2. Some key features and management approaches include:
- Acute occlusion of the internal carotid artery is the underlying cause of 4 to 15% of all ischemic strokes 2.
- Substantial differences exist in the acute management of acute symptomatic internal carotid artery occlusions (ICAO) between centers 2.
- The mainstay of acute management of acute symptomatic ICAO is i.v. thrombolysis when applied within the label and in combination with mechanical thrombectomy in case of intracranial large vessel occlusion 2.
- Surgical approaches, such as carotid endarterectomy (CEA), are an alternative in selected patients when mechanical thrombectomy fails or is not available 2, 3, 4.
Management and Treatment Options
Various treatment options are available for carotid artery occlusion, including:
- Medical therapy, such as anticoagulants and antiplatelets 5, 6.
- Surgical options, such as carotid endarterectomy (CEA) and bypass between the superficial temporal and the middle cerebral arteries (MCA) 2, 3, 4.
- Endovascular therapies, such as angioplasty and stenting 5, 4, 6.
- Emergency surgical treatment, which can be effective in re-establishing carotid flow and vascularization of the hemisphere before irreversible brain damage occurs 3.
Prognosis and Outcomes
The prognosis and outcomes of carotid artery occlusion depend on various factors, including:
- The severity of the occlusion and the resulting neurological deficit 3.
- The timing of treatment, with earlier intervention generally associated with better outcomes 3.
- The quality of the desobstruction and the presence of post-operative complications 3.
- The use of anticoagulant therapy and control of post-operative episodes of hypertension 3.