Sex: M
Vaccine: COVID19
Symptoms: Cerebral venous sinus thrombosis, Computerised tomogram head, Computerised tomogram venography head, Haematology test, Investigation
Clinical narrative: cerebral venous sinus thrombosis; This is a literature report for the following literature source(s).  INTRODUCTION: SARS-CoV-2 induced thrombotic complications are well documented and are a critical component in COVID-19 disease severity and progression. Interestingly, since the vaccines against SARS-CoV-2 were introduced, there have been increasing concerns for serious adverse effects such as cerebral venous sinus thrombosis (CVST) and other forms of venous thromboembolism. While there has been more documented literature on thrombotic complications of vector-based vaccines, relatively less is known about the mRNA vaccines. Pathophysiology of CVST is not fully understood but is usually associated with underlying risk factors such as hereditary hypercoagulable states, infections, vasculitis, or medications like oral contraceptive pills. CASE: A previously healthy 34-year-old male presented two weeks after his second mRNA COVID-19 vaccine dose with a sudden-onset headache. He described it as a pressure-like sensation in the bilateral frontal and parietal regions associated with positional changes, nausea, and vomiting. He denied other neurological symptoms, trauma, recent illnesses, similar headaches in the past, or a family history of hematological disorders. He tried acetaminophen but found no relief. On presentation, he was hemodynamically stable, and basic laboratory workup was unremarkable. A CT brain without contrast revealed hyperdense superior sagittal sinuses, and a subsequent CT Venogram confirmed dural venous sinus thrombosis in the superior sagittal, right transverse, and sigmoid sinuses. Anticoagulation with apixaban was initiated, and he was referred to hematology, which identified a Factor V Leiden heterozygous mutation. Due to the increased relative risk associated with this mutation and the atypical thrombus location, indefinite anticoagulation at a maintenance dose for secondary prophylaxis was recommended. Unfortunately, he experienced another CVST episode eight months later due to non-compliance with anticoagulation therapy. DISCUSSION: CVST associated with COVID-19 mRNA vaccines carries a high mortality rate of 39%, surpassing other causes of CVST. The patient's CVST was postulated to have likely been provoked by the mRNA vaccine. mRNA vaccine-induced CVST pathophysiology involves endothelial dysfunction disrupting the blood-brain barrier or via antibody-mediated thrombotic thrombocytopenia. Healthcare providers should exercise caution in recognizing the potential of mRNA vaccines in precipitating thrombotic events in individuals with underlying hypercoagulable conditions. When patients present with neurological symptoms like post -vaccination headaches, a differential diagnosis of CVST should be considered rather than dismissing the symptoms as mere side effects. In the event of a CVST diagnosis, further investigation for a hypercoagulable state can be pursued at the clinician's discretion. An early diagnosis facilitates prompt treatment initiation and improved outcomes.; Sender's Comments: Based on the temporal relationship, the association between the event cerebral venous sinus thrombosis with COVID-19 Vaccine - Manufacturer Unknown can not be fully excluded.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.