Preexisting mild cognitive impairment as a risk factor for COVID-19 infection: A scoping review and case reports

ABSTRACT

Introduction: SARS-Co-V2 neuroinvasive ability might be the basis for the onset of delirium and neuropsychiatric outcomes. Objective(s) We hypothesized that some infected patients with preexisting cognitive dysfunction may present delirium as unique manifestation of COVID-19 infection or as a prodrome of a new episode consistent with the psychiatric history. Method(s) We conducted a PubMed literature search to verify whether cognitive impairment might predispose to COVID-19. We included three patients with mild cognitive impairment and delirium at admission for SARS-Co-V2 suspected infection. Delirium was diagnosed according to DSM-5 criteria, Cognitive Assessment Method and Coma Glasgow Scale. Result(s) Literature analysis evidenced patients presenting delirium or delirium-like symptoms as clinical manifestation of COVID-19, plus a cognitive impairment, from mild to severe, which preexisted or was evidenced during the acute phase or after the infection. Most studies described delirium in patients with a past neurological/ psychiatric history. Contrasting data emerged on the potential link between COVID-19 and delirium in patients with cognitive impairment and without a past neuropsychiatric history. Our patients had no history of other medical complications. Our first patient had no psychiatric history, the second reported only a depressive episode, and the third had story of bipolar disorder. Delirium resolved completely after 2 days in the first patient. The other patients required 4 and 14 days to resolve delirium appeared as the prodrome of a new psychiatric episode in line with their past history. Conclusion(s) Clinicians should acknowledge the possibility that COVID-19 infection may appear as delirium and acute psychiatric sequelae as unique manifestation.