Characteristics in Doppler Ultrasound of the Carotid Diaphragm Responsible for an Ischemic Stroke

Carotid diaphragms are a non-atheromatous arterial cause of cerebral infarction, especially in young people (≤65 years old). This anomaly is more common in the African or African-American population, although it is more and more often discovered in young Caucasians. This cause of cerebrovascular accident (CVA), known until the 1970s, was later forgotten until a recent revival of interest, probably in connection with the improvement of imagery but also by the discovery that these lesions have a high rate of recurrence in the absence of interventional care. In a Brazilian study, the carotid diaphragm was reported in 10% of patients under the age of 60. The carotid diaphragm is a non-atheromatous overgrowth of the intima of the arterial wall. It appears in imagery in the form of an endoluminal web wider than it is tall. Its preferred seat is the carotid bulb. It is a source, by an embologenic mechanism, of cerebral infarction starting from local thrombus developed within large cerebral arteries. In histology, the lesions are different from atherosclerosis and characterized by a thickening of the intima with proliferation of loose and strewed spindle cells mainly involving the intima. An atheromatous plaque or dissection with detachment of the intima are the two main differential diagnoses of the carotid web. However, the appearance of a diaphragm implanted on a regular wall and the absence of any other localization of atheroma distinguish the lesion of the carotid web from that of a focal atheromatous plate. In addition, the very proximal localization of the carotid web, from the emergence of the internal carotid artery, does not suggest a dissection, the localization of which is usually downstream of the bulb. The baseline exam to detect a carotid diaphragm is a carotid angiography scan, but the abnormalities are often inconspicuous, making diagnosis difficult. We can be led in case of doubt to perform a conventional arteriography, which remains the "gold standard"