Prevalence and Mortality Risk of Neurological Disorders during the COVID-19 Pandemic: An Umbrella Review of the Current Evidence

Introduction: Coronavirus disease 2019 (COVID-19), a global pandemic, has infected approximately 10% of the world's population. This comprehensive review aimed to determine the prevalence of various neurological disorders in COVID-19 without overlapping meta-analysis errors. Methods: We searched for meta-analyses on neurological disorders following COVID-19 published up to March 14, 2023. We obtained 1,184 studies, of which 44 meta-analyses involving 9,228,588 COVID-19 patients were finally included. After confirming the forest plot of each study and removing overlapping individual studies, a re-meta-analysis was performed using the random-effects model. Results: The summarized combined prevalence of each neurological disorder is as follows: stroke 3.39% (95% confidence interval, 1.50-5.27), dementia 6.41% (1.36-11.46), multiple sclerosis 4.00% (2.50-5.00), epilepsy 5.36% (-0.60-11.32), Parkinson's disease 0.67% (-1.11-2.45), encephalitis 0.66% (-0.44-1.77), and Guillain-Barré syndrome 3.83% (-0.13-7.80). In addition, the mortality risk of patients with comorbidities of COVID-19 is as follows: stroke OR 1.63 (1.23-2.03), epilepsy OR 1.71 (1.00-2.42), dementia OR 1.90 (1.31-2.48), Parkinson's disease OR 3.94 (-2.12-10.01). Conclusion: Our results show that the prevalence and mortality risk may increase in some neurological diseases during the COVID-19 pandemic. Future studies should elucidate the precise mechanisms for the link between COVID-19 and neurological diseases, determine which patient characteristics predispose them to neurological diseases, and consider potential global patient management.