Cognitive problems linked to higher death risk in COVID-19 pandemic

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In a new study, researchers found that higher death rates are linked to the COVID-19 pandemic among older adults with cognitive impairment, like Alzheimer’s disease and related dementias (ADRD).

The study is published in JAMA Neurology and was conducted by Lauren Gilstrap et al.

The team conducted a cross-sectional analysis using fee-for-service data on Medicare enrollees aged 65 and older.

They compared mortality rates from 26.7 million enrollees in 2020 with those of 26.9 million enrollees in 2019 in four predetermined groups: people with ADRD; people without ADRD, those with ADRD living in nursing homes, and those without ADRD in nursing homes.

They found that mortality was 24 percent higher among individuals with ADRD in 2020 compared to 2019, and 14 percent higher for people without ADRD.

Among nursing home residents with ADRD, mortality was 36 percent higher in 2020 compared to 2019, versus 25 percent higher for those without ADRD.

When the researchers measured monthly COVID-19 infection rates across the country’s 306 hospital referral regions (or service areas), they found that the areas with the lowest COVID-19 prevalence had no excess mortality among enrollees without ADRD.

But they found eight percent higher mortality among community-dwelling enrollees with ADRD and 14 percent higher mortality among enrollees with ADRD living in nursing homes in those same areas where there was very low COVID-19.

The findings showed that those deaths were probably related less to COVID and more to abrupt changes in the healthcare system.

Related: Aspirin, common anti-inflammatory drugs may prevent COVID-19 deaths.

Previous studies have found that the COVID-19 pandemic is strongly linked to cognitive decline.

In a recent study from Michigan Medicine and published in BMJ Open, researchers found among nearly 150 patients hospitalized for COVID at the beginning of the pandemic, 73% had delirium, a serious disturbance in mental state wherein a patient is confused, agitated and unable to think clearly.

Patients with delirium tended to be sicker, with more comorbidities like hypertension and diabetes and appeared to have more severe COVID-related illness as well.

In that study, the team used patient medical records and telephone surveys following hospital discharge for a group of patients hospitalized in the intensive care unit between March and May 2020.

COVID-19 can lead to reduced oxygen to the brain as well as the development of blood clots and stroke, resulting in cognitive impairment.

In addition, inflammatory markers were greatly increased in patients with delirium. Confusion and agitation could be a result of inflammation of the brain.

Adding insult to injury, care teams often were unable to perform standard delirium reduction techniques, such as exercises designed to get a patient moving or allowing visitors or objects from home to orient patients while in the hospital.

Furthermore, there was a correlation between the use of sedatives and delirium—patients with delirium were sedated more often and frequently at higher doses.

The team found that patients with severe COVID were inherently more delirious and agitated at baseline, perhaps prompting more sedative use.

The study also found that cognitive impairment can persist even after discharge. Almost a third of patients did not have their delirium marked as resolved in their chart upon leaving the hospital and 40% of these patients required skilled nursing care.

Almost a quarter of patients screened positive for delirium based on the assessment by their caretaker. For some patients, these symptoms lasted for months.

In another recent study published in EClinicalMedicine, researchers found evidence of cognitive deficits in people who have recovered from COVID-19.

They found that those with more severe COVID-19 symptoms scored lower on an online series of tests, with performance on reasoning and problem-solving tasks being most affected.

Further analysis of the data indicated that those who received mechanical ventilation to help them breathe while in the hospital had the greatest impairment on cognitive tasks.

The study is from King’s College London and elsewhere. One author is Dr. Adam Hampshire.

In that study, the team examined over 80,000 individuals. A series of online tests had been opened up to the general public just before the pandemic for the BBC2 Horizon’s Great British Intelligence test.

In early 2020 the study team extended the questionnaires to gather information on SARS-CoV-2 infection, the symptoms experienced, and the need for hospitalization.

Out of the 81,337 who provided complete data, 12,689 people suspected they had COVID-19.

The team found a link between deficits in overall cognitive performance and the severity of respiratory symptoms experienced.

The research also found that not all areas of thinking ability correlated in the same way with COVID-19 illness and that some abilities were spared, such as emotional discrimination and working memory.

In comparison, “executive” tasks that require skills in reasoning and problem solving seemed to show the greatest deficit.

The effects in those hospitalized with mechanical ventilation were similar to the average cognitive decline seen over a period of ten years of aging.

These findings add to an increasing body of research that is looking at different aspects of how COVID-19 might be impacting the brain and brain function.

This research is all converging to indicate that there are some important effects of COVID-19 on the brain that need further examination.

If you care about COVID, please read studies about why smokers have a lower risk of COVID-19, and this drug can block multiple COVID-19 variants.

For more information about COVID, please see recent studies about the cause of deadly organ damage in COVID-19, and results showing that vitamin D can be an inexpensive COVID-19 treatment.

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