Guillain-Barré syndrome (GBS) involves immunity system attacks on the nerves. It leads to tingling sensations, nerve weakness, and paralysis. Small series of GBS and single cases were reported during the SARS outbreak. This study evaluates GBS incidence and clinical features in two COVID-19 prevalent regions of Italy.

Lombardy and Veneto in northern Italy had the highest COVID-19 patient numbers. A total of 12 referral hospitals in this region provided the diagnosed GBS cases. The control population involved GBS positive cases between March and April of 2019.

The GBS incidence in 2020 was 0.202 per 100,000 per month. The 2019 GBS incidence was 0.077 per 100,000 per month. The estimated rates per 100,000 per year grew from 0.93 in 2019 to 2.43 in 2020, with a 2.6-fold increase. The GBS incidence estimates in COVID-19 positive patients were 47.9 per 100,000. While the COVID-19 hospitalized patients with GBS incidence were at 236 per 100,000. The COVID-19 positive patients with GBS had a lower MRC sum score of 8.3 to 44.9. While the score for COVID-19 negative patients was in the 26.6 to 56.2 range. The positive cases’ demyelinating subtype, low BP, and ICU admission frequencies were high at 76.6%, 50%, and 66.6%, respectively. The rates for negative subjects were 35.3%, 11.8%, and 17.6%.

The increased GBS incidence during COVID-19 shows a pathogenic link. The COVID-19 patients with GBS had severe, predominant demyelinating. The impairment due to COVID-19 may have contributed to the whole clinical picture severity.