Acute Ischemic Stroke Due to a Mobile Thrombus Adherent to a Carotid Web.

A 48-year-old man presented with impaired consciousness and aphasia. Magnetic resonance imaging (MRI) of the head revealed acute cerebral infarction in the left temporal and parietal lobes. Carotid ultrasonography revealed a mobile structure at the origin of the left internal carotid artery. Cervical MRI using fat-saturation T1 imaging showed an isointense structure at the origin, with a high-signal structure extending toward the head. Digital subtraction angiography revealed contrast stagnation, suggesting the presence of a carotid web (CaW). The mobile structure was released, indicating thrombus resolution. Carotid artery stenting eliminated contrast stagnation and was well-tolerated. This case highlights the diagnostic challenges associated with a CaW-related stroke.