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The authors describe 2 patients with multiple cerebral infarcts and hemorrhagic transformation caused by artery-to-artery emboli. Ulcerated plaques with free-floating thrombus adherent to the plaque were detected at the carotid bifurcation by duplex sonography. No other embolic source could be found. One patient developed an occipital infarction due to carotid emboli passing through a fetal-type posterior communicating artery. Both patients recovered well without recurrence of stroke or transient ischemic attack with antiplatelet treatment only. Follow-up carotid duplex sonography showed disappearance of floating thrombus in 1 patient and consolidation of the lesion in the other.

A forty-six year-old premenopausal woman developed headache, nausea and vomiting, left hemiparesis and seizure two days after parenteral use of progesterone and estradiol. Diabetes mellitus (DM) was found during admission. Computed tomography showed a hemorrhagic infarct in the right frontal lobe and increased density in the superior sagittal sinus (SSS). Left carotid angiography found occlusion of the left internal carotid artery (ICA). Right carotid angiograms failed to show the SSS and inferior sagittal sinus, suggestive of venous sinus thrombosis. Coexistence of the cerebral artery and the venous sinus occlusion has been described infrequently. In this case, the authors postulate that the use of estradiol and progesterone and the underlying DM increased vascular thrombogenicity, which provided a common denominator for thrombosis of both the ICA and the venous sinus.

Five cases of unilateral intracranial internal carotid artery (ICA) occlusion received both carotid angiographic and ultrasonographic studies. The Doppler examination showed that the resistive index (RI) of the common carotid artery (CCA) and ICA was higher but the peak systolic velocity was lower on the diseased side as compared with the normal side. Absence of the diastolic phase was found in the CCA flow in 2 cases and in the ICA flow in 3 cases on the diseased side. The mean CCA flow volume on the diseased side (271 +/- 82 mL/min) was half or less than that on the normal side (680 +/- 86 mL/min) (P < 0.01). The flow volume of the diseased ICA (49 +/- 20 mL/min) was markedly lower than that of the normal side (344 +/- 49 mL/min) (P < 0.01) and was also less than that of the ipsilateral external carotid artery (ECA) (129 +/- 43 mL/min). The Doppler ophthalmic artery flow all showed a forward direction. The authors propose that the following extracranial carotid ultrasonographic findings may be helpful in the prediction of intracranial carotid artery occlusion: (1) diminished frequencies, increased RI, and a more than 50% reduction of flow volume in the CCA as compared with the opposite side; (2) diminished frequencies to loss of the diastolic phase, a more than 50% reduction of the flow volume, and reversed ICA/ECA flow volume in the ICA as compared with the opposite side; and (3) a forward Doppler ophthalmic artery flow.

The authors report 2 cases of common carotid artery (CCA) occlusion and 4 cases of extracranial internal carotid artery (ICA) occlusion with forward Doppler ophthalmic artery flow. The compression test during Doppler study showed that the ophthalmic artery flow was reduced to zero when compressed contralateral to the CCA in 1 case of CCA occlusion and when compressed ipsilateral to the CCA in all 4 cases of ICA occlusion. The angiograms showed that in the 2 cases of CCA occlusion, 1 had the ophthalmic artery originating from the anterior communicating artery, and the other had subclavian steal syndrome with a reversed vertebral flow. In 3 of the 4 cases of ICA occlusion, the ophthalmic artery was found to originate from the ipsilateral middle meningeal artery. Their findings suggest that in cases of extracranial carotid artery occlusion, the forward ophthalmic artery flow is supplied from the contralateral CCA in cases of CCA occlusion and from the branches of the ipsilateral external carotid artery in cases of ICA occlusion, and the vertebrobasilar system plays a less important role.