The unremitting coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) marked a year-long phase of public health adversaries and has severely compromised healthcare globally. Early evidence of COVID-19 noted its impact on the pulmonary and cardiovascular functions, while multiple studies in recent time shed light on its substantial neurological complications, though a comprehensive understanding of the cause(s), the mechanism(s), and their neuropathological outcomes is scarce. In the present review, we conferred evidence of neurological complications in COVID-19 patients and shed light on the SARS-CoV-2 infection routes including the hematogenous, direct/neuronal, lymphatic tissue or cerebrospinal fluid, or infiltration through infected immune cells, while the underlying mechanism of SARS-CoV-2 invasion to the central nervous system (CNS) was also discussed. In an up-to-date manner, we further reviewed the impact of COVID-19 in developing diverse neurologic manifestations associated with CNS, peripheral nervous system (PNS), skeletal muscle, and also pre-existing neurological diseases, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, epilepsy, and myasthenia gravis. Furthermore, we discussed the involvement of key factors including age, sex, comorbidity, and disease severity in exacerbating the neurologic manifestations in COVID-19 patients. An outlook of present therapeutic strategies and state of existing challenges in COVID-19 management was also accessed. Conclusively, the present report provides a comprehensive review of COVID-19-related neurological complications and emphasizes the need for their early clinical management in the ongoing COVID-19 pandemic.
Keywords COVID-19 • SARS-CoV-2 • CNS • PNS • Neuroinvasion • COVID-19 pandemic • Neurological complications
Highlights• Coronavirus disease 2019 (COVID-19)-associated complications involve substantial neurological manifestations.• SARS-CoV-2 infection routes include the hematogenous, neuronal, lymphatic tissue/cerebrospinal fluid, or infiltration through infected immune cells.• COVID-19 promotes neurologic manifestations associated with the central and peripheral nervous system and exacerbates the pre-existing neurological and neurodegenerative conditions. • Patient's age, sex, comorbidity, and severity of the infection are key factors that determine the extent of neurologic manifestations in COVID-19 patients.