Acute ischemic stroke due to floating thrombus of ascending aorta: An acute and subacute complication of SARS-CoV-2 infection

•Embolic stroke of unknown source (ESUS) is frequent in patients with COVID-19.•Aortic thrombosis is a possible cause of ESUS but rarely without vessel wall damage.•COVID-19 driven inflammation can lead to thrombosis in non-atherosclerotic vessels.•COVID-19 aortic thrombosis without signs of wall damage can cause embolic stroke.•In COVID-19 acute ischemic stroke, we suggest active search for aortic thrombosis.