This stroke which occurs when blood clots occur in the arteries that supply blood to the brain, is the most common form of stroke, but this is the first time it has been reported in people vaccinated with AstraZeneca serum.
Up to now, all cases of thrombi recorded after receiving the Oxford vaccine had appeared in veins (especially the brain). In addition, all had low levels of platelets Y antibodies against platelet factor 4 (PF4), a protein that promotes clot formation.
The information on the three new cases – all of them reported in young adults – is detailed in a letter signed by a dozen doctors and researchers and published in the journal ‘Journal of Neurology Neurosurgery & Psychiatry’.
In all cases, ischemic stroke was associated with blockages of large arteries (both carotid and middle cerebral artery) and two patients also had hepatic and cerebral venous thrombosis. All three had extremely low platelet levels, confirmed anti-PF4 antibodies, and elevated D-dimer (also related to clotting).
The first patient, a 30-year-old woman, experienced intermittent pain in the right side of your head and in the eyes six days after receiving the vaccine. Five days later, she woke up sleepy and with weakness in her left face, arm, and leg.
She was diagnosed with an obstruction of the right middle cerebral artery with a cerebral infarction, and after undergoing brain surgery, she was medicated with the anticoagulant fondaparinux, but she died. Twelve days after being vaccinated, the second patient, about 30 years old, He presented headache, confusion, weakness in the left arm, and loss of vision on the left side.
The images showed blockages in several vessels, including both carotids (the arteries that supply blood to the hemispheres of the brain), those that supply the heart and lungs (pulmonary embolism), and the left transverse sinus (one of the cerebral venous sinuses). His platelet count increased after plasma collection and replacement and intravenous corticosteroids. Fondaparinux was administered and improved.
The third patient, a man in his 40s, presented three weeks after receiving the vaccine with trouble speaking and understanding language (dysphasia). The images showed a clot in the left middle cerebral artery. She received a platelet and plasma transfusion, and fondaparinux, and is still stable.
For the lead author of the study, David Werring, from University College London, the three cases suggest that, in addition to cerebral venous thrombosis, the vaccine-induced reaction can also lead to clots that block the arteries of the brain and cause a Ischemic stroke.
“Young patients who develop ischemic stroke after receiving the vaccine should be urgently evaluated with laboratory tests (including platelet count, D-dimers, fibrinogen, and anti-PF4 antibodies), and treated by a multidisciplinary team ( hematology, neurology, stroke, neurosurgery and neuroradiology) to rapidly apply treatments such as intravenous immunoglobulin, methylprednisolone, plasmapheresis and non-heparin anticoagulants, for example fondaparinux, argatroban or direct oral anticoagulants “, the authors advise.
In a comment published in the same journal, Hugh Markus of the Department of Clinical Neurosciences at the University of Cambridge believes the study highlights that “Immune-mediated coagulopathy can also cause arterial thrombosis, including ischemic stroke, although venous thrombosis and especially cerebral venous sinus thrombosis seem more frequent”. And although it recommends being alert to identify possible cases of patients with thrombi after vaccination, it underlines that these side effects “are rare, and much less frequent than cerebral venous thrombosis and ischemic stroke associated with the covid-19 infection itself”