Acute Confusion as an Initial Presentation of SARS-CoV-2 Infection

Background and purpose: The respiratory manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been extensively documented. There is emerging evidence that coronavirus disease 2019 (COVID-19) has number of other presenting features which might not be related to the severity of the respiratory disease. We have previously described a case of hypoactive delirium as the first manifestation of COVID-19 without profound lung disease. Here we present five cases of elderly patients, without a prior history of dementia and had no overt COVID-19-related pneumonia, who presented with the acute onset of delirium as the primary manifestation of COVID-19.

Methods: This retrospective, single-center study performed a health informatics search to produce a list of patients who were admitted with acute confusion and tested positive for the SARS-CoV-2 virus between March 1 and June 30, 2020. The electronic medical admission notes were screened for all patients with confusion who tested positive for SARS-CoV-2. Patients with a history of dementia and a high risk of delirium were excluded, such as severe COVID-19-related pneumonia or any other infection, malignancy, drugs, or severe illness of any kind.

Results: During the first wave of the COVID-19 pandemic our hospital experienced just over 3,000 SARS-CoV-2 positive patients, and 45 of them had documented confusion upon admission. Secondary causes for their acute confusion were excluded. Five patients were identified as having delirium as the initial presentation of COVID-19-related illness without significant COVID-19-related pneumonitis. None of them had overt chest symptoms or a previous history of confusion, and the 3 patients who underwent head CT scans had normal findings.

Conclusions: This case series illustrates the importance of recognizing acute confusion as the first manifestation of COVID-19 in susceptible individuals.