Tag: CNS dysfunction

Long-term neurological dysfunction associated with COVID-19: Lessons from influenza and inflammatory diseases?

Abstract:

As the COVID-19 pandemic persists, SARS-CoV-2 infection is increasingly associated with long-term neurological side effects including cognitive impairment, fatigue, depression, and anxiety, colloquially known as “long-COVID.” While the full extent of long-COVID neuropathology across years or even decades is not yet known, we can perhaps take direction from long-standing research into other respiratory diseases, such as influenza, that can present with similar long-term neurological consequences.

In this review, we highlight commonalities in the neurological impacts of influenza and COVID-19. We first focus on the common potential mechanisms underlying neurological sequelae of long-COVID and influenza, namely (1) viral neurotropism and (2) dysregulated peripheral inflammation. The latter, namely heightened peripheral inflammation leading to central nervous system dysfunction, is emerging as a shared mechanism in various peripheral inflammatory or inflammation-associated diseases and conditions.

We then discuss historical and modern examples of influenza- and COVID-19-associated cognitive impairment, depression, anxiety, and fatigue, revealing key similarities in their neurological sequelae. Although we are learning that the effects of influenza and COVID differ somewhat in terms of their influence on the brain, as the impacts of long-COVID grow, such comparisons will likely prove valuable in guiding ongoing research into long-COVID, and perhaps foreshadow what could be in store for individuals with COVID-19 and their brain health.

Source: Volk P, Rahmani Manesh M, Warren ME, Besko K, Gonçalves de Andrade E, Wicki-Stordeur LE, Swayne LA. Long-term neurological dysfunction associated with COVID-19: Lessons from influenza and inflammatory diseases? J Neurochem. 2023 Nov 28. doi: 10.1111/jnc.16016. Epub ahead of print. PMID: 38014645. https://onlinelibrary.wiley.com/doi/10.1111/jnc.16016 (Full text)

Biomedical Perspectives of Acute and Chronic Neurological and Neuropsychiatric Sequelae of COVID-19

Abstract:

The incidence of infections from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent for coronavirus disease 2019 (COVID-19), has dramatically escalated following the initial outbreak in China in late 2019, resulting in a global pandemic with millions of deaths. Although the majority of infected patients survive, and the rapid advent and deployment of vaccines have afforded increased immunity against SARS-CoV-2, long term sequelae of SARS-CoV-2 infection have become increasingly recognized. These include, but are not limited to, chronic pulmonary disease, cardiovascular disorders, and proinflammatory-associated neurological dysfunction that may lead to psychological and neurocognitive impairment. A major component of cognitive dysfunction is operationally categorized as “brain fog” which comprises difficulty with concentration, forgetfulness, confusion, depression, and fatigue.

Multiple parameters associated with long-term neuropsychiatric sequelae of SARS-CoV-2 infection have been detailed in clinical studies. Empirically elucidated mechanisms associated with the neuropsychiatric manifestations of COVID-19 are by nature complex, but broad based working models have focused on mitochondrial dysregulation leading to systemic reductions of metabolic activity and cellular bioenergetics within CNS structures. Multiple factors underlying the expression of brain fog may facilitate future pathogenic insults leading to repetitive cycles of viral and bacterial propagation. Interestingly, diverse neurocognitive sequelae associated with COVID-19 are not dissimilar from those observed in other historical pandemics, thereby providing a broad and integrative perspective on potential common mechanisms of CNS dysfunction subsequent to viral infection. Poor mental health status may be reciprocally linked to compromised immune processes and enhanced susceptibility to infection by diverse pathogens.

By extrapolation, we contend that COVID-19 may potentiate the severity of neurological/neurocognitive deficits in patients afflicted by well-studied neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease. Accordingly, the prevention, diagnosis, and management of sustained neuropsychiatric manifestations of COVID-19 are pivotal health care directives and provide a compelling rationale for careful monitoring of infected patients, as early mitigation efforts may reduce short- and long-term complications.

Source: Stefano GB, Büttiker P, Weissenberger S, Ptacek R, Wang F, Esch T, Bilfinger TV, Kream RM. Biomedical Perspectives of Acute and Chronic Neurological and Neuropsychiatric Sequelae of COVID-19. Curr Neuropharmacol. 2021 Dec 23. doi: 10.2174/1570159X20666211223130228. Epub ahead of print. PMID: 34951387. https://pubmed.ncbi.nlm.nih.gov/34951387/