Basilar artery occlusion
Basilar artery occlusion is a posterior circulation large-vessel stroke that threatens the brainstem, cerebellum, and thalami, presenting with rapidly progressive quadriparesis, cranial nerve palsies, and impaired consciousness, up to locked-in syndrome or coma. Diagnosis requires urgent CT angiography, and management is emergent reperfusion with IV alteplase followed by mechanical thrombectomy in eligible patients.
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What this article covers
- Overview
Definition: basilar artery occlusion is thrombotic or embolic occlusion of the basilar artery, formed by the union of the vertebral arteries, supplying the pons, midbrain, cerebellum, thalami, and…
- Epidemiology
Proportion of strokes: posterior circulation strokes account for a minority of all ischemic strokes, and basilar artery occlusion is a small but disproportionately lethal subset of these.
- Risk factors
Large-artery atherosclerosis: intracranial vertebral-basilar junction and midbasilar artery atherosclerosis is a recognized precursor to occlusion.
- Pathophysiology
Vascular territory at risk: the basilar artery gives rise to paramedian and circumferential perforators supplying the pons and midbrain, superior and anterior inferior cerebellar arteries, and…
- Clinical features
Classic triad: rapidly progressive quadriparesis or quadriplegia, bilateral cranial nerve palsies (ophthalmoplegia, facial weakness, dysarthria, dysphagia), and impaired consciousness together strongly suggest basilar occlusion.
- Differential diagnosis
Anterior circulation (middle cerebral artery) stroke: unilateral hemiparesis, hemisensory loss, aphasia, or neglect, without the bilateral cranial nerve findings of basilar occlusion.
- Diagnosis
Basis of diagnosis: basilar artery occlusion is diagnosed by demonstrating occlusion or high-grade stenosis of the basilar artery on vascular imaging in a patient with a compatible clinical syndrome…
- Management
First step, airway and hemodynamic stabilization: urgent airway protection for depressed consciousness or bulbar dysfunction, since brainstem involvement predisposes to aspiration; blood pressure is…
- Complications
Locked-in syndrome: complete ventral pontine infarction with preserved consciousness but quadriplegia and anarthria requires long-term ventilatory and nutritional support and communication devices.
- Prognosis
High untreated mortality: basilar artery occlusion carries a mortality up to 80% to 90% without reperfusion, reflecting the critical structures within its territory.
- Prevention
Blood pressure control: a target of less than 130/80 mm Hg after the acute period reduces recurrent stroke risk.
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Related articles
- Ischemic stroke
Ischemic stroke is sudden focal neurologic deficit from arterial occlusion confirmed by infarction on neuroimaging. Diagnosis relies on urgent noncontrast head CT to exclude hemorrhage; treatment is IV alteplase within 4.5 hours and mechanical thrombectomy for large-vessel occlusion within an extended window, followed by antiplatelet therapy and risk-factor control.
- Cerebellar stroke
Cerebellar stroke, ischemic or hemorrhagic infarction of the cerebellum, presents with vertigo, truncal ataxia, dysarthria, and limb incoordination and is diagnosed with brain MRI when CT is falsely reassuring. Its defining danger is delayed swelling that compresses the brainstem and fourth ventricle, which is treated with emergent decompressive suboccipital craniectomy.
- Vertebral artery dissection
A tear in the vertebral artery wall, spontaneous or from neck trauma or manipulation, that causes posterior circulation ischemia through thrombus formation or direct luminal narrowing. Presents with posterior neck or occipital headache plus brainstem or cerebellar signs, most classically a lateral medullary (Wallenberg) syndrome; diagnosed with MRI/MRA or CT angiography of the neck and treated with antithrombotic therapy.
- Lacunar stroke
Small subcortical infarct, under 1.5 cm, from occlusion of a single penetrating artery, most often caused by hypertensive lipohyalinosis, producing one of five classic pure motor, pure sensory, ataxic hemiparesis, dysarthria-clumsy hand, or mixed sensorimotor syndromes without cortical signs, diagnosed by MRI and managed with the standard acute stroke pathway plus aggressive antiplatelet, statin, and blood pressure secondary prevention.
- Carotid artery stenosis
Carotid artery stenosis is atherosclerotic narrowing of the extracranial internal carotid artery that raises ischemic stroke risk, graded by percent luminal narrowing on duplex ultrasound. Symptomatic stenosis of at least 50% warrants urgent revascularization; asymptomatic stenosis under 80% is managed with best medical therapy alone, including a high-intensity statin and antiplatelet agent.