A study involving hospitalized adults today in JAMA Network Open finds that severe COVID-19 negatively affects brain health, but no more so than pneumonia, heart attack, or other critical illnesses.
Copenhagen University Hospital researchers in Denmark compared the cognitive, psychiatric, and neurologic test results of 120 COVID-19 patients with those of 100 matched healthy controls and 125 patients hospitalized for other critical diseases at two academic hospitals in 2020 or 2021. Face-to-face follow-up was conducted after an average of 18 months. Average participant age was 61 to 66 years.
Overall cognition was evaluated with the Screen for Cognitive Impairment in Psychiatry (SCIP) and the Montreal Cognitive Assessment (MoCA).
Underlying conditions may lead to neurologic problems
At 18 months, COVID-19 patients had worse cognition than healthy controls (estimated average SCIP score, 59.0 vs 68.8; estimated average MoCA score, 26.5 vs 28.2) but not controls hospitalized for other conditions (average SCIP score, 61.6; average MoCA score, 27.2). A total of 38.3% of 120 COVID-19 patients had MoCA scores below 26.
COVID-19 patients also performed worse than healthy controls on all other psychiatric and neurologic tests, but except for executive dysfunction (Trail Making Test Part B relative mean difference [RMD], 1.15), their brain health wasn't more impaired than that of hospitalized controls.
Patients with COVID-19 had a higher rate of psychiatric and neurologic symptoms than hospitalized controls (96.7% vs 83.2%), but after adjusting for multiple testing, only loss of smell was significantly more common at 18 months.
Underlying factors such as cardiovascular disease, hypertriglyceridemia, and hypertension can cause subtle neurological abnormalities and may explain the similarity between patients with COVID-19 and controls.
Likewise, of neurologic signs, after adjusting for multiple testing, only loss of smell remained less common among healthy controls than among COVID-19 patients (16.0% vs 38.7%; odds ratio [OR] for the nerve impairment variable, 0.20; reciprocal OR, 5.0).
"Underlying factors such as cardiovascular disease, hypertriglyceridemia, and hypertension can cause subtle neurological abnormalities and may explain the similarity between patients with COVID-19 and controls," the study authors wrote.
COVID-19 patients had a higher rate of new psychiatric diagnoses (ie, depression and anxiety) than did healthy controls (OR, 11.24) but not compared with hospitalized control patients after multiplicity adjustment (OR, 2.05). Patients with COVID-19 also had higher scores on the Fatigue Assessment Scale than healthy controls (RMD, 1.48).
Illness severity, hospitalization
Fifty-six COVID-19 patients were examined 6 months after hospital admission using the MoCA, Mini International Neuropsychiatric Interview (MINI), objective neurologic exam, and a symptom interview. Another 16 COVID-19 patients were examined with the MoCA at hospital release.
The average MoCA score among COVID-19 patients rose from hospital release to 18 months (21.7 vs 26.5) but declined slightly from 6 to 18 months (from 27.4 to 26.5). Psychiatric diagnoses assessed using the MINI rose over 6 to 18 months (from 17.9% to 32.1%; OR, 3.00), as did neurologic exam findings (from 25.0% to 51.8%; OR, 4.75).
"Long-term associations with brain health might not be specific to COVID-19 but associated with overall illness severity and hospitalization," the researchers wrote. "This information is important for putting understandable concerns about brain health after COVID-19 into perspective."
