Sex: M
Vaccine: COVID19
Symptoms: Magnetic resonance imaging head, Oxygen saturation, Platelet count, Prothrombin time, Red blood cell count
Clinical narrative: subarachnoid hemorrhages; This is a literature report.   A 40-year-old male patient received BNT162b2 (BNT162B2), as dose 1, single (Lot number: EL0142) for covid-19 immunisation. The patient's relevant medical history included: "atraumatic" (unspecified if ongoing); "Severe headache" (unspecified if ongoing), notes: 9 day history, with progression into the worst headache of his life. The patient's concomitant medications were not reported. The following information was reported: SUBARACHNOID HAEMORRHAGE (hospitalization, medically significant, life threatening), outcome "recovering", described as "subarachnoid hemorrhages". The patient was hospitalized for subarachnoid haemorrhage (hospitalization duration: 9 day(s)). The patient underwent the following laboratory tests and procedures: Activated partial thromboplastin time: normal; Angiogram: unrevealing for visible blood; unrevealing for visible blood; Angiogram cerebral: unrevealing for any specific structural causes to, notes: explain the subarachnoid hemorrhages. Two diagnostic cerebral angiograms performed 1 week apart; unrevealing for any specific structural causes to, notes: explain the subarachnoid hemorrhages. Two diagnostic cerebral angiograms performed 1 week apart; Blood pressure measurement: 115/56 mmHg; Body temperature: 37.2 Centigrade; Computerised tomogram head: unrevealing for visible blood; C-reactive protein: normal; Heart rate: 67, notes: Unit: beats per minute (bpm); International normalised ratio: normal; Lumbar puncture: which showed xanthochro, notes: with elevated red blood cell count at greater than 97,000; Magnetic resonance imaging head: evidence of focal areas of, notes: subarachnoid hemorrhage along right and left frontal convexities; Oxygen saturation: 100 %, notes: on room air; Platelet count: normal; Prothrombin time: normal; Red blood cell count: greater than 97,000; Respiratory rate: 16, notes: Unit: beats per minute (bpm); Ultrasound Doppler: negative, notes: for intracranial vasospasms. Therapeutic measures were taken as a result of subarachnoid haemorrhage.  Clinical course: As with any origination of ideas meant to counteract the severity of the SARS-CoV-2 virus, so was the goal of the swift and vast production of vaccines made for public use in a short time frame. While vaccines, serving as critical strategies for the ongoing pandemic have always maintained a clinical effectiveness to severe disease and even death, that is not without rudimentary outliers. A healthy, atraumatic 40-year-old male with no significant past medical history, presented with a 9-day history of a severe self-limiting headache with progression into the worst headache of his life associated with nuchal rigidity and posterior bilateral leg pain and tightness following the first dose vaccination with Pfizer (EL0142). Vital signs on admission included blood pressure 115/56 mmHg, pulse 67 beats per minute (bpm), respiratory rate 16 breaths per minute, temperature 37.2C and oxygen saturation 100% on room air. Initial CT Head and CTA Head and Neck were unrevealing for visible blood. Nonetheless heightened clinical suspicion prompted a lumbar puncture which showed xanthochromia with elevated red blood cell count at greater than 97,000. MRI Brain revealed evidence of focal areas of subarachnoid hemorrhage along right and left frontal convexities. Laboratory data was essentially non-contributory with a normal platelet count, pro time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), and C-reactive protein (CRP). Two diagnostic cerebral angiograms performed 1 week apart were unrevealing for any specific structural causes to explain the subarachnoid hemorrhages and repeat Transcranial Doppler Ultrasounds remained negative for intracranial vasospasms. The initial meningeal symptoms subsided after a short course of dexamethasone taper and the patient remained neurologically intact from initial presentation through hospital discharge 9 days later. This case depicts the need to portray amplified awareness given the clinical hallmark and presentation of subarachnoid hemorrhages (SAH), with the spontaneous subtype being extremely rare and difficult to disentangle, comprising less than 1% of all SAH (2). Workup to include various etiologies including Reversible Cerebral Vasoconstriction Syndrome, posterior reversible encephalopathy syndrome (PRES), CNS vasculitis, auto-immune meningitis, cerebral aneurysms, and arteriovenous malformations (3) need to be ruled-out before the possibility of vaccine complications can be considered. While the mechanism of action is still unknown, with no reported episodes of Covid-19 vaccine associated subarachnoid hemorrhages, the workup must begin. As such, SAH should be considered critical in order to avoid misdiagnosis in neurologically intact patients so as to ensure an exact therapeutic strategy with good prognosis. Learning Objectives: * Recognize the various unsought outcomes that can originate from a contemporary vaccine * Distinguish the significance of misdiagnosis of subarachnoid hemorrhages (SAH).  No follow-up attempts are possible.; Sender's Comments: As there is limited information in the case provided, the causal association between the event subarachnoid haemorrhage and the suspect drug BNT162B2 cannot be excluded. The case will be reassessed once new information is available. 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.