Publisher Correction: Neurological complications after first dose of COVID-19 vaccines and SARS-CoV-2 infection

COVID-19 Neuroimaging Update: Pathophysiology, Acute Findings, and Post-Acute Developments

COVID-19 has prominent effects on the nervous system with important manifestations on neuroimaging. In this review, we discuss the neuroimaging appearance of acute COVID-19 that became evident during the early stages of the pandemic. We highlight the underlying pathophysiology mediating nervous system effects and neuroimaging appearances including systemic inflammatory response such as cytokine storm, coagulopathy, and para/post-infections immune mediated phenomena. We also discuss the nervous system manifestations of COVID-19 and the role of imaging as the pandemic has evolved over time, including related to the development of vaccines and the emergence of post-acute sequalae such as long COVID.

Guillain-Barré Syndrome Induced by Vaccination Against COVID-19: A Systematic Review and Meta-Analysis

Guillain-Barré syndrome (GBS) is a rare but serious immune-mediated neurological condition characterized by damage to the peripheral nervous system. Two-thirds of cases of GBS are diagnosed following infection; however, vaccination has also been linked to GBS pathogenesis. The aim of this systematic review and meta-analysis was to establish the prevalence of GBS following vaccination against the SARS-CoV-2 virus, which causes COVID-19, describe the clinical and neurophysiological characteristics, and identify potential determinants. A systematic review of the literature regarding post-vaccination GBS was conducted using the PubMed database. Seventy papers were included. The pooled prevalence of GBS after vaccination against COVID-19 per has been established to be 8.1 (95% CI 30-220) per 1,000,000 vaccinations. Vaccination with vector vaccines - but not mRNA - has been associated with an increased risk of GBS. More than 80% of the patients developed GBS within 21 days following the first dose of the vaccination. The interval between the vaccination and GBS was shorter in patients who were vaccinated with mRNA versus vector vaccines (9.7±6.7 days versus 14.2±6.6 days). Epidemiological findings regarding post-vaccination GBS revealed a higher prevalence in males and people between the ages of 40 and 60 years, with a mean age of 56.8±16.1 years. The most common type was the acute inflammatory demyelinating polyneuropathy type. Most cases responded well to treatment. In conclusion, vaccination against COVID-19 with vector vaccines seems to increase the risk of GBS. GBS occurring following vaccination does differ in characteristics from GBS during the pre-COVID-19 era.

Triggers of Guillain-Barré Syndrome: Campylobacter jejuni Predominates

Guillain-Barré syndrome (GBS) is a rare immune-mediated acute polyradiculo-neuropathy that typically develops after a previous gastrointestinal or respiratory infection. This narrative overview aims to summarise and discuss current knowledge and previous evidence regarding triggers and pathophysiology of GBS. A systematic search of the literature was carried out using suitable search terms. The most common subtypes of GBS are acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). The most common triggers of GBS, in three quarters of cases, are previous infections. The most common infectious agents that cause GBS include Campylobacter jejuni (C. jejuni), Mycoplasma pneumoniae, and cytomegalovirus. C. jejuni is responsible for about a third of GBS cases. GBS due to C. jejuni is usually more severe than that due to other causes. Clinical presentation of GBS is highly dependent on the structure of pathogenic lipo-oligosaccharides (LOS) that trigger the innate immune system via Toll-like-receptor (TLR)-4 signalling. AIDP is due to demyelination, whereas in AMAN, structures of the axolemma are affected in the nodal or inter-nodal space. In conclusion, GBS is a neuro-immunological disorder caused by autoantibodies against components of the myelin sheath or axolemma. Molecular mimicry between surface structures of pathogens and components of myelin or the axon is one scenario that may explain the pathophysiology of GBS.