Olfactory dysfunction: A plausible source of COVID-19-induced neuropsychiatric symptoms

Olfactory dysfunction and neuropsychiatric symptoms are commonly reported by patients of coronavirus disease 2019 (COVID-19), a respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Evidence from recent research suggests linkages between altered or loss of smell and neuropsychiatric symptoms after infection with the coronavirus. Systemic inflammation and ischemic injury are believed to be the major cause of COVID-19-related CNS manifestation. Yet, some evidence suggest a neurotropic property of SARS-CoV-2. This mini-review article summarizes the neural correlates of olfaction and discusses the potential of trans-neuronal transmission of SARS-CoV-2 or its particles within the olfactory connections in the brain. The impact of the dysfunction in the olfactory network on the neuropsychiatric symptoms associated with COVID-19 will also be discussed.

Automated summary

Olfactory dysfunction and neuropsychiatric symptoms are common in COVID-19 patients. Recent research suggests a connection between altered smell and neuropsychiatric symptoms after infection with SARS-CoV-2. Systemic inflammation and ischemic injury are believed to be the main causes, but there is also evidence of a neurotropic property of the virus. This article summarizes the neural correlates of olfaction and discusses the potential transmission of SARS-CoV-2 within the olfactory connections in the brain.