Tic Movement of Thyroid Cartilage as a Cause for Localized Cerebral Embolism: Mimics of Embolic Stroke of Undetermined Source with Non-Stenotic Carotid Plaque.

Several studies have suggested that non-stenotic carotid plaque was a risk factor for embolic stroke of undetermined source in some patients. However, individual backgrounds of these patients is unclear. We encountered a 64-years-old female with cerebral emboli, from an apparently stable non-stenotic carotid plaque (only 1.42mm thick) at the distal left common carotid artery, caused by violent tic movement of thyroid cartilage under well controlled dyslipidemia. Even though the plaque appeared thin and stable, mechanical stimulation could cause multiple, unnaturally localized emboli by stimulation-induced atherogenesis and plaque rupture, resulting in a misdiagnose of embolic stroke of undetermined source with non-stenotic carotid plaque.