A prospective investigation found that although there remained a cognitive deficit for at least a year and a half following a severe SARS-CoV-2 infection, overall cognitive issues were similar to those observed in patients hospitalized for other serious illnesses.
Michael Eriksen Benros, MD, Ph.D., of Copenhagen University Hospital in Denmark, and co-authors found that, when compared to healthy controls, people hospitalized with COVID-19 had significantly worse long-term overall cognition as measured by the Screen for Cognitive Impairment in Psychiatry (SCIP) and the Montreal Cognitive Assessment (MoCA).
However, the researchers reported in JAMA Network opens in a new tab or window that scores on the SCIP (P=0.12) and the MoCA (P=0.07) at 18-month follow-up were similar to those hospitalized for other severe illness, such as pneumonia, myocardial infarction, or other conditions requiring intensive care.
On the majority of other long-term mental and neurological examinations, hospitalized COVID-19 patients scored similarly to other critically ill patients, except having lower executive function scores.
According to Benros, long-term associations between COVID and cognition may not be unique to SARS-CoV-2 but rather are more closely linked to hospitalization and the severity of the illness overall.
In an email to MedPage Today, he stated, “Our study demonstrates that individuals with COVID-19 requiring hospitalization were more affected on their brain health regarding neurological, cognitive, and psychiatric symptoms than matched healthy controls.” However, both groups were similarly affected when comparing COVID-19 patients to non-COVID-19 patients matched on similar disease severity, for example, because of other non-COVID infections.
According to earlier studies, 10.7% of hospitalized patients in Brazil who were released from the hospital following a severe SARS-CoV-2 infection experienced long-term damage that lasted for a year. opens in a new tab or window. Additionally, 12.45% of COVID-19 survivors who were released from Wuhan hospitals in the first half of 2020 had cognitive impairment 12 months later in a new tab or window. However, some studies have indicated that long-term neurocognitive dysfunction may be more widespread. For example, one study found that nearly half of the patients hospitalized with COVID may have at least one cognitive domain impairment.
Benros noted that there have been remarkably few long-term follow-up clinical investigations comparing COVID-19 consequences to other serious medical diseases.
Between March 2020 and March 2021, the researchers matched 120 hospitalized COVID-19 patients with 125 hospitalized controls and 100 healthy controls at two hospitals in Copenhagen. Hospitalized controls included 50 patients with non-COVID pneumonia, 50 patients with myocardial infarction, and 25 patients with non-COVID critical care. The study excluded participants who had cognitive impairment before enrollment.
The average age of hospitalized COVID patients was 61 years old, with 58% of them being men. An average of 19.4 months after hospital release, participants were invited for an in-person follow-up evaluation and underwent structured face-to-face interviews with two medical professionals.
Based on SCIP and MoCA scores, overall cognition was the main result. Lower SCIP scores signify greater impairment; the scores have no maximum limit and begin at 0. MoCA scores run from 0 to 30, with a score of less than 26 indicating cognitive impairment and being deemed abnormal. Neurological impairments, anxiety, depression symptoms, and executive function were among the secondary outcomes.
The mean SCIP scores at the 18-month follow-up were 61.6 for hospitalized controls, 59.0 for COVID-19 patients in hospitals, and 68.8 for healthy controls. Hospitalized COVID patients had a mean MoCA score of 26.5, hospitalized controls a mean of 27.2, and healthy controls a mean of 28.2.
Hospitalized COVID patients had lower secondary outcome scores than healthy controls, but overall there was no difference in these scores between hospitalised COVID patients and hospitalised controls. On the executive function portion of the Trail Making Test (Part B), however, COVID patients performed worse than hospitalized controls, with a 15% relative mean difference (P=0.04).
Benros and co-authors pointed out that 12% to 50% of people had chronic cognitive impairment one year after infection, according to earlier research on cognitive performance in COVID-19 patients. In line with earlier studies, we discovered that 38% of COVID-19 patients had MoCA scores below 26 at the 18-month follow-up and did worse on all cognitive tests when compared to the healthy population.
The researchers noted that the study period included a variety of SARS-CoV-2 strains with differing virulence and potential for long-term consequences. The adoption of the SCIP, which has a very modest battery of cognitive tests, was another restriction. Furthermore, cognitive scores from before the epidemic were not accessible.
