Spontaneous Thrombosis of Cerebral Arteriovenous Malformation Post COVID-19

Background and Aims: Spontaneous regression of arteriovenous malformations is a rare phenomenon and can occur as a result of prothrombotic and hypercoagulable states. Coincidentally SARS-CoV-2 infection is associated with endothelial dysfunction, prothrombotic state and systemic inflammation. We aimed to describe a singular prothrombotic complication of COVID-19. Methods: We report a case of spontaneous thrombosis of a cerebral arteriovenous malformation, due to progressive venous drainage thrombosis, in a COVID-19 patient. Results: A 70-year-old man presented to emergency department after sudden onset of left hemiparesis and focal seizures, sixteen days after COVID-19 diagnosis. Head CT with CT angiography (figure 1) and brain MRI (figure 2) disclosed a thrombosed right parietal pial arteriovenous malformation, feed by the right anterior cerebral artery and by the inferior division of the medium cerebral artery, with signs of venous drainage thrombosis and perinidal edema. There was an additional small perinidal hematoma (10 mm diameter). Digital subtraction angiography confirmed the progressive thrombosis of the venous drainage of the brain AVM, with no early arteriovenous shunt, and with significant flow stagnation at the arterial feeders and without flow within AVM nidus. The patient presented a favorable evolution with improvement of the hemiparesis and was discharged 12 days later. Conclusions: COVID-19 is associated with a hypercoagulable state, potentially leading to thrombotic cerebrovascular events. To our knowledge this is the first case of spontaneous thrombosis of cerebral AVM in the setting of SARS-CoV-2 infection.