COVID-19 and Cognitive Impairment: Severity, Evolution, and Functional Impact during Inpatient Rehabilitation

Abstract

Objective: To determine the frequency, magnitude, and change in cognitive impairment in patients with COVID-19 undergoing acute inpatient rehabilitation. We secondarily evaluated correlates of cognitive impairment and the relationship between cognition and functional gain. Design: Cross-sectional observational study with assessments at admission and discharge Setting: Acute inpatient rehabilitation unit within a large, urban academic medical center Participants: 77 patients hospitalized for COVID-19 and subsequently admitted to an inpatient rehabilitation unit between March-August 2020, 45 of whom were re-assessed at discharge. Interventions: N/A Main Outcome Measures: Montreal Cognitive Assessment (MoCA) scores on admission and discharge (when available) and Quality Indicator for Self-Care (QI-SC) scores on admission and discharge. Results: 62/77 (80.5%) of patients demonstrated cognitive deficits on the MoCA at admission: 39/77 (50.6%) were mildly impaired, 20/77 (26%) moderately impaired, and 3/77 (3.9%) severely impaired. Cognitive impairment was associated with a prior history of delirium, but not age or length of acute care hospitalization. 32/45 (71.1%) patients with discharge scores improved and met the MoCA minimally clinically important difference (MCID); however, 35/45 (77.8%) continued to score in the impaired range. Patients who met the MoCA MCID demonstrated significantly greater QI-SC score gains than those that did not meet the MCID (p=.02). Conclusion: Cognitive impairment is common among hospitalized COVID-19 patients requiring acute inpatient rehabilitation. Cognitive impairment improves over the course of inpatient rehabilitation, and is associated with functional gain. Nonetheless, cognitive deficits frequently remain present at discharge, indicating the need for systematic assessment and follow-up, especially given the association with functional outcome.