COVID-19 and Guillain-Barré syndrome in early pandemia in Lombardia: Increased incidence or increased seroprevalence?

Background and aims: Several studies reported increased incidence of Guillain-Barre' Syndrome (GBS) after Zika epidemic, SARS-CoV and MERS, and more recently SARS-CoV-2 infection. We estimate incidence and describe clinical characteristics and outcome of GBS in COVID-19 patients in one of the most affected regions by COVID-19 of the world, Lombardia. Methods: A multi-center observational study on neurological complications in COVID-19 patients was conducted in 20 Neurology Units by the Italian society of Hospital Neuroscience (SNO). Adult patients admitted to Neurological units between February-April 2020 with COVID19-GBS were included. Results: 38 COVID19-GBS patients had mean age of 60.7 years and male frequency of 86.8%. Mean interval between COVID-19 onset and GBS onset was 15.1 days. CSF albuminocytologic dissociation was detected in 71.4% of cases, PCR for SARS-CoV-2 negative in all 15 tested patients, and anti-ganglioside antibodies positive in 43.7%. Based on neurophysiology, 81.8% of patients had a diagnosis of AIDP diagnosis, 12.1% AMSAN and 6% AMAN. 29 patients have been treated with intravenous Immunoglobulin (IVIg), two with plasma exchange (PE), two with PE followed by IVIg and five untreated. The course was favorable in 76.3% of patients, stable in 10.5%, while 13.1% worsened, of which three died. The estimated occurrence rate in Lombardia is 0.5 GBS cases per 1000 COVID-19 infections. Conclusion: We detected an increased incidence of GBS in COVID-19 patients which can reflect higher risk of GBS in COVID-19 patients or be secondary to an increase of prevalence of prior infection in that period.