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For further information, see CMDT Part 12-05: Occlusive Cerebrovascular Disease

Key Features

Essentials of Diagnosis

  • Sudden onset

    • Weakness and numbness of an extremity

    • Aphasia

    • Dysarthria

    • Unilateral blindness (amaurosis fugax)

  • Bruit heard loudest in the mid neck

General Considerations

  • Unlike the other vascular territories, symptoms of occlusive cerebrovascular disease are predominantly due to emboli

  • The ischemia is reversible (transient ischemic attacks [TIAs]) when collateral flow reestablishes perfusion but is a sign that the risk of additional emboli and stroke is high

  • Most ischemic strokes are due to emboli from the heart

  • One-quarter of all ischemic strokes may be due to emboli from an arterial source; approximately 90% of these emboli originate from the proximal internal carotid artery

  • Intracranial atherosclerotic lesions are less uncommon in western populations but are the most common location of cerebrovascular disease in Asian populations

Clinical Findings

Symptoms and Signs

  • Ischemic symptoms of TIAs

    • Generally last only a few seconds to minutes

    • May continue for up to 24 hours

  • Most common lesions associated with carotid disease are in the cortex with both motor and sensory involvement

  • Emboli to the retinal artery cause unilateral blindness which, when transient, is called amaurosis fugax

  • Posterior circulation symptoms referable to the brainstem, cerebellum, and visual regions of the brain are

    • Due to atherosclerosis of the vertebral basilar systems

    • Much less common than carotid disease

  • Carotid artery bruits

    • Correlation between the degree of stenosis and the presence of the bruit is poor

    • Absence of a bruit does not exclude the possibility of carotid stenosis

  • Nonfocal symptoms, such as dizziness and unsteadiness, seldom are related to cerebrovascular atherosclerosis

Differential Diagnosis

  • Transient ischemic attack

  • Ischemic stroke

  • Intracerebral hemorrhage

  • Subdural or epidural hematoma

  • Space-occupying lesion, eg, brain tumor

  • Seizure (Todd paralysis)

  • Migraine

  • Peripheral causes of vertigo, eg, Ménière disease

  • Hypoglycemia

  • Guillain-Barré syndrome

  • Multiple sclerosis

  • Aortic dissection


Imaging Studies

  • Duplex ultrasonography

    • Imaging modality of choice

    • Has high specificity and sensitivity for detecting and grading degree of stenosis at the carotid bifurcation

    • Prospective screening valuable in timing intervention in asymptomatic patients since about 10% will have evidence of plaque progression in a given year

  • Magnetic resonance angiography or CT angiography

    • Provides excellent depiction of full anatomy of the cerebrovascular circulation from aortic arch to cranium

    • Each of these modalities may have false-positive or false-negative findings

  • Use at least two modalities to confirm degree of stenosis

  • Cerebral angiography is reserved for cases that cannot be resolved by magnetic resonance or CT angiography


Asymptomatic patients

  • Carotid intervention is likely beneficial in those

    • With no neurologic symptoms but with carotid stenosis on imaging

    • Who are considered to be ...

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