Post COVID-19 Vaccination Encephalitis as a Cause of Subacute Progressive Dementia: A Case Report and Literature Review.

The coronavirus disease 2019 (COVID-19) pandemic has caused more than 500 million infected cases, causing a new public health crisis.1 Many people are vaccinated against COVID-19 to prevent infection and bring an end to the pandemic. However, various complications have been reported.1,2 Autoimmune encephalitis is a progressive encephalopathy that can develop rapidly (usually in less than 6 weeks) caused by brain inflammation.3 In this case report, we present a rare case of a 59-year-old woman who visited an outpatient clinic because of subacute onset cognitive decline. She was diagnosed with post COVID-19 vaccination encephalitis. We observed 1-year cognitive outcomes and neuroimaging changes of the patient. Clinical, neuroimaging, and cerebrospinal fluid (CSF) findings of the patient are described below.