A Unique Case of Horner's Syndrome Following Subintimal Haematoma Within an Atherosclerotic Plaque.

Background and Importance We describe a patient with Horner's syndrome caused by an extensive intraparietal hematoma in the wall of the internal carotid artery confused with an arterial dissection. Detection of such pathology instead of dissection or arteritis is important as the management is different. As far as the authors know, it is the first case in which a haematoma within an atherosclerotic plaque is clinically related Horner's syndrome. Clinical Presentation A 81-year-old man presented with acute right hemiplegia and loss of vision of the left eye due to a central retinal artery occlusion. The patient underwent a computerised angiotomography which demonstrated left internal carotid artery occlusion with recanalisation after carotid bifurcation. Clinically, the patient developed a syndrome of Claude-Bernard Horner which replaced the diagnosis on the suspicion that it was a carotid artery dissection. The patient had miosis and ptosis of left eye. In the magnetic resonance angiography, an intramural of a possible hematoma was observed. It was decided to perform surgical treatment of the carotid lesion. Conclusion As this clinical case shows, there are symptomatic courtships that must be studied in detail so as not to confuse the carotid dissection with critical stenosis of the internal carotid artery.