text: Vaccine induced immune thrombotic thrombocytopenia and cerebral venous sinus thrombosis post COVID 19 vaccination a systematic review The common reported adverse effects of COVID 19 vaccination consist of the injection sites local reaction followed by several non specific flu like symptoms However rare cases of vaccine induced immune thrombotic thrombocytopenia VITT and cerebral venous sinus thrombosis CVST after viral vector vaccines ChAdOx1 nCoV 19 vaccine Ad26 COV2 vaccine have been reported Herein we systemically reviewed the reported cases of CVST and VITT following the COVID 19 vaccination This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses PRISMA statement We searched PubMed until May 19 2021 and the following Keywords were used COVID Vaccine Neurology AstraZeneca COVID vaccine ChAdOx1 nCoV 19 COVID vaccine AZD1222 COVID vaccine Janssen COVID vaccine Johnson Johnson COVID vaccine Ad26 COV2 COVID vaccine The authors evaluated the abstracts and titles of each article for screening and inclusion English reports about post vaccine CVST and VITT in humans were collected Until May 19 we found 877 articles with the searched terms We found 12 articles which overall present clinical features of 36 patients with CVST and VITT after the ChAdOx1 nCoV 19 vaccine Moreover two articles were noted which present 13 patients with CVST and VITT after Ad26 COV2 vaccine The majority of the patients were females Symptom onset occurred within one week after the first dose of vaccination Range 4 19 days Headache was the most common presenting symptom Intracerebral hemorrhage ICH and or Subarachnoid hemorrhage SAH were reported in 49 of the patients The platelet count of the patients was between 5 and 127 cells 10 sup 9 sup l PF4 IgG Assay and d Dimer were positive in the majority of the reported cases Among 49 patients with CVST at least 19 patients died 39 due to complications of CVST and VITT Health care providers should be familiar with the clinical presentations pathophysiology diagnostic criteria and management consideration of this rare but severe and potentially fatal complication of the COVID 19 vaccination Early diagnosis and quick initiation of the treatment may help to provide patients with a more favorable neurological outcome 