Microemboli in MCA ipsilateral to occluded common carotid artery: an observation and short review of the literature.

Sixty-five years old patient suffering from acute stroke was treated by rTPA intravenously. TCD monitoring of both middle cerebral arteries (MCA) was carried out simultaneously with administration of rTPA. Seven microemboli were found in right and four in left MCA. Duplex ultrasound, CT angiography and digital subtractional angiography revealed occlusion of left common carotid artery (CCA) and moderate to severe stenosis of right internal carotid artery (ICA). The case presented here is, to the best of our knowledge, the first description of MCA microemboli signals in patient with occlusion of ipsilateral CCA. This location of occlusion eliminates the possibility of microemboli passage from carotid bulb proximally to the site of occlusion through the ipsilateral external carotid artery or from the distal stump of occluded ICA. The possibility of emboli from contralateral stenosed ICA through the patent anterior communicating artery (ACoA) or from the distal stump of occluded CCA seems to be the most probable explanation.