Intracranial Hemorrhage Due to Potential Rupture of an Arteriovenous Malformation after BNT162b2 COVID-19 mRNA Vaccination in a Young Korean Woman: Case Report.

Inoculation with the Pfizer-BioNTech coronavirus infection-19 (COVID-19) vaccine (BNT162b2) has been approved in Korea. Although it is generally safe, several possible side effects have been reported. The present report describes a 28-year-old woman who developed an intracerebral hemorrhage in her right temporal lobe after the first dose of the Pfizer-BioNTech COVID-19 vaccine. The patient complained of a persistent headache for four days after the first dose, along with right third nerve palsy and drowsiness. Non-enhanced brain computed tomography confirmed a 5.0 × 3.7 × 5.0 cm-sized intracranial hemorrhage in the right temporal lobe due to the rupture of an arteriovenous malformation (AVM). Transfemoral cerebral angiography revealed that blood was supplied to the AVM by the right middle cerebral artery branch and drained into the right transverse sinus. The patient underwent surgical treatment for AVM nidus removal with hematoma evacuation on the day of admission. Her condition stabilized 10 days postoperatively. These findings indicate that clinicians should be aware that cerebral hemorrhage caused by AVM rupture may be a side effect of inoculation with the BNT162b2 mRNA COVID-19 vaccine.