High Frequency of Cognitive Impairment Observed in COVID-19 Hospitalizations

Jacqueline H. Becker, PhD

Cognitive dysfunction, commonly described as brain fog, has been a frequent complaint in people who have survived COVID-19 infection, but its association with severity of the disease is not currently well characterized.

Led by Jacqueline H. Becker, PhD, Division of General Internal Medicine, Icahn School of Medicine at Mount Sinai, investigators examined rates of cognitive impairment in patients who survived COVID-19 treated in outpatient, emergency department (ED), or inpatient hospital settings.

Becker and colleagues observed a high frequency of cognitive impairment several months after COVID-19, including impairments in executive functioning, processing speed, category fluency, memory encoding, and recall among those hospitalized.

Methods

An analysis of the cross-sectional study occurred from April 2020 - May 2021 from a cohort of patients with COVID-19, with follow-up in the Mount Sinai Health System registry.

For inclusion, participants were required to be aged ≥18 years, English or Spanish speakers, positive for SARS-CoV-2, and had no history of dementia. Demographic characteristics including age, race, and ethnicity were collected from self-reports.

In assessment of cognitive functioning, investigators used well-validated neuropsychological measures.

These consisted of Number Span forward (attention) and backward (working memory), Trail Making Test Part A and Part B (processing speed and executive functioning, respectively), phonemic and category fluency (language), and the Hopkins Verbal Learning Test–Revised (memory encoding, recall, and recognition).

Investigators used logistic regression to assess the association between cognitive impairment and COVID-19 care site, with adjustment for race and ethnicity, smoking, body mass index, comorbidities, and depression.

Findings

Data show participants (n = 740) had a mean age of 49 years, with 63% (n = 464) women and a mean time from COVID-19 diagnosis of 7.6 months.

Other demographics including race had patients self-identify as Black (15%), Hispanic (20%), or White (54%), while Other race and ethnicity made up 11% of patients.

Prominent deficits were seen in processing speed (18%, n = 133), executive functioning (16%, n = 118), phonemic fluency (15%, n = 111) and category fluency (20%, n = 148), memory encoding (24%, n = 178), and memory recall (23%, n = 170).

After adjusted analyses, hospitalized patients were shown to be more likely to have impairments in attention (odds ratio, OR, 2.8; 95% CI, 1.3 - 5.9), executive functioning (OR, 1.8; 95% CI, 1.0 - 3.4), and category fluency (OR, 3.0; 95% CI, 1.7 - 5.2) compared to those in the outpatient group.

Additionally, data show hospitalized patients were more likely to have impairments in memory encoding (OR: 2.3; 95% CI, 1.3 - 4.1) and memory recall (OR, 2.2; 95% CI, 1.3 - 3.8), in comparison to the outpatient group.

Those treated in the emergency department had a higher likelihood of impaired category fluency (OR, 1.8; 95% CI, 1.1 - 3.1) and memory encoding (OR: 1.7, 95% CI, 1.0 - 3.0), in comparison to those treated in the outpatient setting.

Takeaways

Investigators pointed out the association of COVID-19 with executive functioning has elevated questions on long term treatment in these patient groups.

“Future studies are needed to identify the risk factors and mechanisms underlying cognitive dysfunction as well as options for rehabilitation,” investigators wrote.

The study, “Assessment of Cognitive Function in Patients After COVID-19 Infection,” was published in JAMA Network Open.