COVID-19 vaccine-induced parkinsonism due to LGI1 antibody encephalitis: case report and brief literature review

Anti-LGI1 encephalitis is an autoimmune disorder of the brain, characterized by subacute cognitive impairment, faciobrachial dystonic seizures, and hyponatremia. Although rare, recent reports suggest that LGI1 encephalitis may be triggered following COVID-19 exposure whether through infection or vaccination. It usually presents with insidious progression which, along with old age predominance, may delay the diagnosis. We herein report a 67-year-old patient with positive LGI1 antibody titers, who developed subacute parkinsonism after serial COVID-19 vaccination. To our knowledge, this is the first documented case report highlighting a potential association between COVID-19 vaccination and the development of parkinsonism in the context of LGI1 encephalitis.