Clinical and Electrophysiological Characteristics of Guillain-Barré Syndrome Across Pre-Pandemic, Pandemic, and Post-Pandemic Periods: A Ten-Year Retrospective Cohort Study.

INTRODUCTION

The COVID-19 pandemic markedly altered patterns of exposure to respiratory and gastrointestinal pathogens, healthcare-seeking behaviors, and environmental immune triggers. Guillain-Barré syndrome (GBS), an immune-mediated polyradiculoneuropathy frequently preceded by an infectious event, may therefore exhibit changes in clinical presentation or electrophysiologic subtype distribution. However, it remains unclear whether the clinical and electrophysiological characteristics of GBS have changed across pandemic periods.

METHODS

This retrospective cohort included adults diagnosed with GBS between March 2015 and October 2025 at a tertiary referral center. Patients were grouped into pre-pandemic, pandemic, and post-pandemic periods. Clinical features, antecedent events, severity scores, and electrophysiologic subtypes (classified using Uncini criteria) were compared. Group comparisons were performed using chi-square, Fisher's exact test, and non-parametric tests where appropriate.

RESULTS

Seventy patients were included: 31 pre-pandemic, 24 during the pandemic, and 15 post-pandemic. Age, sex, CSF findings, clinical and electrophysiological subtype distribution were similar across groups. Sensory and motor symptom subcategories and deep tendon reflexes did not differ. Antecedent event types differed significantly across periods (p=0.015). Admission Hughes score, MRC sum score, and mEGRIS score showed significant differences, indicating more severe presentation in the pre-pandemic group. Post-hoc comparisons suggested that these differences were primarily driven by comparisons between pre- and post-pandemic groups.

CONCLUSION

Despite pandemic-related epidemiological changes, the fundamental clinical and electrophysiological characteristics of GBS remained stable. However, differences in initial disease severity may reflect changes in environmental exposures and healthcare-seeking behavior rather than intrinsic alterations in disease pathophysiology.