Hafsteinsdóttir, BrynhildurDalemo, EllenElíasdóttir, ÓlöfÓlafsson, ElíasAxelsson, Markus2025-11-202025-11-202023-03Hafsteinsdóttir, B, Dalemo, E, Elíasdóttir, Ó, Ólafsson, E & Axelsson, M 2023, 'Decreased incidence of Guillain-Barré syndrome during the COVID-19 pandemic : a retrospective population-based study', Neuroepidemiology, vol. 57, no. 1, pp. 1-6. https://doi.org/10.1159/0005277260251-5350706835910d99e9d4-7cef-4c86-8d07-6a03b4a90cd13636682285144516695unpaywall: 10.1159/000527726https://hdl.handle.net/20.500.11815/7054The Author(s). Published by S. Karger AG, Basel.Background: Guillain-Barré syndrome is an immune-mediated acute inflammatory polyneuropathy that is associated with various triggers, including certain infections and vaccines. It has been suggested that both SARS-CoV-2 infection and vaccination may be triggering factors for Guillain-Barré syndrome, but evidence remains equivocal. Here, we conducted a population-based incidence study of Guillain-Barré syndrome spanning the 3 years immediately prior to and the 2 years during the pandemic. Methods: Cases were identified by searching a regional diagnostic database for the ICD-10 code for Guillain-Barré syndrome. Individuals who fulfilled the Brighton criteria for Guillain-Barré syndrome were included. Information on clinical presentation, laboratory values, and vaccination status were retrieved from medical records. We calculated the incidence immediately prior to and during the pandemic. Results: The Guillain-Barré syndrome incidence rate was 1.35/100,000 person-years for the pre-pandemic period and 0.66/100,000 person-years for the pandemic period (incidence rate ratio: 0.49; p = 0.003). Three cases were temporally associated with SARS-CoV-2 infection and 1 case each to the AstraZeneca and Pfizer-BioNTech COVID-19 vaccines. Conclusions: Our results show that the incidence of Guillain-Barré syndrome decreased during the pandemic. This is most likely due to decreased prevalence of triggering infections due to social restrictions. Our findings do not support a causal relationship between Guillain-Barré syndrome and COVID-19.61327731-6eninfo:eu-repo/semantics/openAccessCOVID-19Guillain-Barr syndromeIncidencePopulation-based studiesVaccinePandemicsHumansSARS-CoV-2COVID-19/epidemiologyCOVID-19 VaccinesGuillain-Barre Syndrome/epidemiologyInfluenza VaccinesRetrospective StudiesNeurology (clinical)EpidemiologySDG 3 - Good Health and Well-being/dk/atira/pure/researchoutput/researchoutputtypes/contributiontojournal/article10.1159/000527726