This document describes 3 cases of acute ischemic stroke patients found to have thrombotic occlusion of the common carotid artery (CCA) before treatment with intravenous tissue plasminogen activator (IV-TPA). Ultrasound and imaging showed mobile thrombi in the CCA extending into the internal and external carotid arteries in all 3 cases. Despite persistent CCA/internal carotid artery occlusion, 2 cases showed complete middle cerebral artery recanalization 2 hours after IV-TPA. While immediate neurological improvement was not observed, patients' NIH Stroke Scale scores improved before discharge. The document discusses CCA occlusion types and importance of intracranial collaterals, and concludes that acute CCA thrombotic occlusions should not

1. Thrombotic Occlusion of the Common Carotid Artery in Acute Ischemic Stroke Vijay K Sharma Consultant Neurologist National University Hospital Singapore [email_address]

7. Clinical, imaging, sonographic characteristics with recanalization patterns, neurological recovery and disposition data of the three cases with acute CCA occlusions Sharma VK et al. Eur J Neurol 2007;14:237-240

8. Case 1- Sonographic and imaging findings Acute mobile thrombi on transverse (a) and longitudinal (b) views on B-mode cervical duplex sonography. Computerized tomographic (c) of neck showing non-opacification (arrows) of right CCA. Final cerebral infarctions seen on diffusion weighted MRI (d) Note the thrombus in ICA also (b). Schematic representation of CCA occlusion & intracranial flow patterns..Note anterior cross-filling of ipsilateral MCA via ACOM and flow reversal in ipsilateral ACA. 1- Aortic arch; 2-Innominate artery; 3- CCA; 4- ECA; 5-ICA; 6-Subclavian artery; 7-Veretbral artery; 8- intracranial ICA; 9-A1 segments of ACA; 10-M1 segments of MCA; 11-A2 segments of ACA; 12-Anterior communicating artery; 13-Ophthalmic artery; 14-Basilar artery.

9. Case 2- Sonographic and imaging findings Acute mobile thrombi on transverse (a) and longitudinal (b) views on B-mode cervical duplex sonography. s CT angiogram of neck (c) showing non-opacification of left CCA. Final cerebral infarctions seen on brain CT scan (d). 1- Aortic arch; 2-Innominate artery; 3- CCA; 4- ECA; 5-ICA; 6-Subclavian artery; 7-Veretbral artery; 8- intracranial ICA; 9-A1 segments of ACA; 10-M1 segments of MCA; 11-A2 segments of ACA; 12-Anterior communicating artery; 13-Ophthalmic artery; 14-Basilar artery. Schematic representation of CCA occlusion and intracranial flow patterns. It shows thrombotic occlusion of left CCA, ICA, ECA,intracranial ICA, ipsilateral MCA and ACA. No intracranial collateral flow is seen.

10. Case 3- Sonographic and imaging findings Acute mobile thrombi on transverse (a) and longitudinal (b) views on B-mode cervical duplex sonography. Digital subtraction angiograms (c) of neck showing non-opacification of right CCA. Final cerebral infarctions seen on diffusion weighted MRI (d) Schematic representation of CCA occlusion and intracranial flow patterns. Thrombotic occlusion of right CCA, ECA, ECA and intracranial ICA with anterior cross-filling of ipsilateral MCA via ACOM and flow reversal in ipsilateral ACA. 1- Aortic arch; 2-Innominate artery; 3- CCA; 4- ECA; 5-ICA; 6-Subclavian artery; 7-Veretbral artery; 8- intracranial ICA; 9-A1 segments of ACA; 10-M1 segments of MCA; 11-A2 segments of ACA; 12-Anterior communicating artery; 13-Ophthalmic artery; 14-Basilar artery.