[Miller-Fisher/Guillain-Barré overlap syndrome following COVID-19 vaccination].

Background: Anti-GQ1B syndrome includes a group of diseases characterized by antibody-mediated polyneuropathy. Guillain Barre syndrome (GBS) and the Miller-Fisher syndrome (MFS) have been related to COVID-19 vaccine application.

Clinic Case: 48-year-old man, with history of Pfizer-BioNTech vaccination against COVID-19, 5 days prior to the symptoms, who assisted to the Emergency room with blurred vision and diplopia; adding dysarthria, facial diplegia and left upper limb weakness after 48 hours.