Guillain-Barré Syndrome During the Outbreak of Omicron in Southern China: A Multicenter Case-Control Study.

Purpose: The largest nationwide outbreak of Omicron, a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variant, occurred between December 2022 and February 2023 in China. This multicenter case-control study investigated the clinical features of GBS during this period.

Methods: The clinical characteristics of patients diagnosed with GBS associated with SARS-CoV-2 were assessed during an Omicron outbreak at 14 referral hospitals in Hubei Province, Southern China. In the case-control study, patients with GBS were identified and diagnosed between 2021 and 2022 at Tongji Hospital in Wuhan, Hubei province.

Results: Forty-one patients were diagnosed with GBS during the Omicron outbreak. The median patient age was 57.5 years, and 51.2% were male. The median period between the preceding infection and onset of neurological symptoms was 10 days. The majority of the patients (38 cases [92.7%]) presented with classic sensorimotor neuropathy, with the lower limbs involved more often; 17 cases (41.5%) were accompanied by cranial neuropathies, which was most observed with the bilateral or unilateral facial paralysis (13 cases [31.7%]). Albuminocytologic dissociation was observed in 27 patients (71.1%), and mild pleocytosis was found in five patients (12.2%), with a maximum of 22 cells/mm³. Thirty-two patients finished the electrophysiological studies, and axonal variants were confirmed in 21 cases predominantly as acute motor-sensory axonal neuropathy (40.6%) or acute motor axonal neuropathy (25.0%). Anti-ganglioside antibodies were detected in 19 patients (46.3%). Intravenous immunoglobulin administration improved the patients' symptoms.

Conclusion: The characteristics of SARS-CoV-2-associated GBS during the Omicron outbreak appear clinically as sensorimotor neuropathy, with a predominant electrophysiological axonal form. A mainly classic post-infectious immune-mediated mechanism may be involved in this process, such as a temporal profile of clinical symptoms, axon-associated autoantibodies, and improvement by immunotherapy.