Carotid Floating Thrombus With Patent Foramen Ovale: An Unusual Cause of Stroke in Young.

Embolic strokes of undetermined source (ESUS) form a quarter of all ischemic strokes, with the majority of them being thromboembolic. Carotid free-floating thrombus (CFFT) is a rare cause of ischemic stroke. There are no current guidelines outlining the management of CFFT. Patent foramen ovale (PFO) is a common cardiac abnormality that is generally not considered to be an independent risk factor for stroke. But, in certain stroke cases involving younger patients (<55 years old), PFO may be a source of paradoxical embolism. However, ipsilateral atherosclerosis in carotids has a low prevalence in patients with clinically significant PFO. We present an unusual case of stroke with two possible etiologies, CFFT, and a large PFO, begging the question, which lesion was the culprit?