Dementia and other adverse effects on the brain are occurring in some COVID-19 survivors, an ominous finding for the millions infected — even those with only mild symptoms, according to two new studies.
As with prior findings on long COVID, it underscores the potential for more side effects for a large chronically ill population during the pandemic and after. The authors of one study examined hospitalized adult pneumonia patients with SARS-CoV-2 infection, matching them with a control group with pneumonia of a different etiology. Patients were matched by age, gender, and race/ethnicity at 110 healthcare facilities in the United States.
“Among 10,403 patients with pneumonia associated with SARS-CoV-2 infection, 312 patients (3%) developed new onset dementia over a median period of 182 days,” the authors reported.1 After adjusting for multiple potentially confounding variables, the results held and the findings were confirmed.
“Three percent — that is about one in 30 who developed new onset dementia over the next six months,” said Daniel Griffin, MD, PhD, a clinician and research scientist at Columbia University in New York City. Griffin was not involved in the studies but reviewed both papers in his ongoing series of COVID-19 clinical updates.2
“They looked at a number of confounders, but this was consistent throughout — a significantly higher chance of going on to develop dementia after SARS-CoV-2,” he said. “Rather disturbing, when we think about just how many people have been infected with SARS-CoV-2.”
The implications of the findings are that screening for cognitive deficits among survivors of SARS-CoV-2 should be considered, the authors noted. “The dementia seen in survivors of SARS-CoV-2 infection mainly affects executive, memory, attentional, and visuospatial functions, with relatively preserved orientation and language,” they concluded.
The authors of the second study examined brain changes in the UK Biobank, a large biomedical database and research resource.3 The authors investigated brain changes in 785 UK Biobank participants aged 51 to 81 years who were scanned twice. There were 384 controls in the group.
“What was really exciting about this was that they included 401 cases who tested positive for infection for SARS-CoV-2 — between the two scans,” Griffin said. “We have a baseline scan, we have a SARS CoV-2 infection, and then we have a second scan.”
The researchers found distinctive differences in comparing the brain scans of those infected to the controls.
“These included a great reduction in gray matter thickness and tissue contrast in the orbitofrontal cortex,” Griffin said. “That’s an area where there are extensive connections with sensory areas as well as limbic structures involved in emotion and memory. Consistent with other reports, the participants showed larger cognitive decline between the [designated] time points. [There are] concerning impacts on the brain.”
Trying to determine if severity of illness was a factor, the researchers then excluded cases that had been hospitalized.
“They saw [the same] consistent differences in both populations,” he said. “Even folks who think of it as maybe milder COVID, not requiring hospitalizations, still [could have] these changes.”
REFERENCES
- Qureshi AI, Baskett WI, Huang W, et al. New onset dementia among survivors of pneumonia associated with severe acute respiratory syndrome coronavirus 2 infection. Open Forum Infectious Diseases 2022; Mar 7. https://academic.oup.com/ofid/advance-article/doi/10.1093/ofid/ofac115/6543929
- YouTube. TWiV 874: COVID-19 clinical update #105 with Dr. Daniel Griffin. Published March 12, 2022. https://www.youtube.com/watch?v=73HIb86EQ5s&t=392s
- Douaud G, Lee S, Alfaro-Almagro F, et al. SARS-CoV-2 is associated with changes in brain structure in UK Biobank. Nature 2022; Mar 7. doi: 10.1038/s41586-022-04569-5. [Online ahead of print].
Dementia and other adverse effects on the brain are occurring in some COVID-19 survivors, an ominous finding for the millions infected — even those with only mild symptoms, according to two new studies.
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