Basilar Occlusion Syndromes: An Update

Abstract

Basilar artery occlusions (BAOs) are a subset of posterior circulation strokes. Particular issues relevant to BAOs include variable and stuttering symptoms at onset resulting in delays in diagnosis, high morbidity and mortality, and uncertain best management. Despite better imaging techniques, diagnosis, and therefore treatment, is often delayed. We will present the most common signs and symptoms of posterior circulation strokes. Data on optimal treatment strategies are gathered from multiple case series, registries, and one randomized trial, which was stopped early. Possible etiologies of BAOs, acute, and subacute treatment strategies and special topics in neuroimaging of the posterior fossa are discussed. This review may be helpful to neurohospitalists who are managing patients with acute stroke as well as emergency room physicians and neurologists.

Keywords: basilar artery occlusion; basilar artery thrombosis; intra-arterial treatment; intravenous thrombolysis; stroke.

Figure 1.

Clinical presentation and angiographic comparison of 2 cases of basilar artery occlusion seen at the University Hospital within 1 week of each other meant to illustrate similarities and differences of etiology, symptoms at onset, and outcomes. The arrow points out a persistent high-grade mid-basilar stenosis after recanalization in case 2.

Figure 2.

Axial sections through representative noncontrast head CT scans demonstrating: (A) normal head CT with superimposed posterior circulation Acute Stroke Prognosis Early CT (pc-ASPECT) scoring territories. A scan with no hypodensity would receive a score of 10; 1 to 2 points are subtracted for hypodensity in each of the areas represented. One point is subtracted for hypodensity in the right and left cerebellum, thalamus, and occipital lobe and 2 points are subtracted for any hypodensity in the pons or midbrain. B, Left panel demonstrates a normal posterior fossa and normodense basilar artery. The middle and right panels depict a hyperdense basilar artery (arrow). Early ischemic changes in the left midbrain are noted (*). CT indicates computed tomography.