Teaching NeuroImage: Thromboembolic stroke in ICA stenosis
Stefan Isenmann, MD,
Martin Skalej, MD and
Johannes Dichgans, MD
From the Departments of Neurology (Drs. Isenmann and Dichgans) and Neuroradiology (Dr. Skalej), University of Tübingen Medical School, Germany. Dr. Skalej is currently with the University of Magdeburg, Department of Neuroradiology, Magdeburg, Germany. Dr. Isenmann is currently with the University of Jena, Department of Neurology, Jena, Germany.
Address correspondence and reprint requests to Dr. Stefan Isenmann, University of Jena Medical School, Department of Neurology, Erlanger Allee 101, D-07747 Jena, Germany; e-mail: stefan.isenmann{at}med.uni-jena.de
A 74-year-old man with right-sided amaurosis fugax had an ultrasoundexamination revealing right internal carotid artery (ICA) stenosis(figure 1, A and B). Angiography (figure 2A) showed a proximalICA stenosis of approximately 90% according to NASCET criteria1and a distal thrombus. The patient was anticoagulated with heparin.Invasive treatment options were discussed, but 16 hours laterthe patient had a stroke (figure 2B), with left sided hemiplegiaand hemineglect. The insult was caused by arterio-arterial thromboembolismrather than ICA occlusion, because follow-up ultrasound showedthe right ICA still with the same high degree of stenosis (figure 1, C and D).In ICA stenosis, embolic cerebral infarction isusually ascribed to plaque rupture, and imaging often showsmultiple emboli.2,3 In contrast, here the heterozygous factorV Leiden mutation (R506Q) may have contributed to thrombus formationin the post-stenotic artery.4,5
Figure 1. Ultrasound examinations. A, B, prestroke: cross (A) and longitudinal (B) sections showing only minute residual flow signal (red; arrow in B) in the right internal carotid artery (ICA) (10 kHz, maximal systolic velocity: >300 cm/second). C, D, poststroke: cross section (C) with flow measurement (D, >13 kHz, maximal systolic velocity: >200 cm/second, consistent with a 90% stenosis). The original ICA lumen is outlined with a dotted line in A, C.
Figure DSA (A) showing a 90% stenosis of the proximal right internal carotid artery (ICA) (arrows), and a thrombus located distal to the stenosis (arrowheads), occupying most of the ICA diameter. Cranial CT scan (B) 3 months later showing a large demarcated infarction of the right MCA territory (scale bar, 5 cm).
Disclosure: The authors report no conflicts of interest.
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