Occlusion of the extracranial internal carotid artery in the acute stroke; angiographic findings within 6 hours.

We studied by angiography 80 patients within 6 hours from the onset of symptoms of supratentorial ischaemic stroke. Occlusion of the internal carotid artery in the extracranial segment was found in 19 patients, at the bifurcation in 11 and at the cervical level in 8. While in the chronic phase of stroke, internal carotid artery occlusion in the cervical segment is an uncommon angiographic finding, we found a high frequency of occlusion at this level (8 out of 19) in our patients. Cervical segment occlusion may be due to a dissecting aneurysm or to an intracranial carotid artery occlusion (embolic or atherothrombotic) with subsequent migration of the clot down to this level. A direct embolic occlusion may be postulated as well.