A Systematic Review of the COVID Vaccine's Impact on the Nervous System.

Aims & objectives: The objective of this study was to conduct a systematic review of research pertaining to the COVID-19 vaccine and its association with neurological complications.

Method: We performed a comprehensive search of the literature using Google Scholar, PubMed, and NCBI databases from December 2021 to December 2022. For Google Scholar, PubMed, and NCBI databases we used the following key search terms: "neurological adverse effects", "COVID-19 vaccination", "SARS-CoV-2", CNS complications, and CNS adverse effects. Two reviewer authors individually searched and assessed the titles and abstracts of all articles. The third reviewer resolved the disagreement between them. Data were documented regarding title, study location, type of study, type of COVID-19 vaccine, type of neurological complications/ adverse effects, and sample size.

Results: From our findings, it is confirmed that these neurological complications like Guillain- Barre syndrome (23.6%), Neuromyelitis Optica spectrum disorder (5.5%), Neuropathy (6.9%), Transverse Myelitis (8.3%) and Acute disseminated Encephalomyelitis (4.1%) are majorly affected in most of the people. The increase in risks associated with SARS-CoV-2 infection far outweighs any previously reported associations with vaccination.

Conclusion: We found no safety signal was observed between COVID-19 vaccines and the immune- mediated neurological events. Before assuming a causal relationship, the side effects of the COVID-19 vaccine should first be carefully examined to rule out known associated factors. Symptom onset was within two weeks of vaccination in the majority of cases; as such, this seems to be a high-risk period warranting vigilance.