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

INTRODUCTION: SARS-Co-V2 neuroinvasive ability might be the basis for the onset of delirium and neuropsychiatric outcomes. OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Clinicians should acknowledge the possibility that COVID-19 infection may appear as delirium and acute psychiatric sequelae as unique manifestation. DISCLOSURE: No significant relationships.