WEDNESDAY, Nov. 25, 2020 (HealthDay News) -- Delirium is often the first symptom of COVID-19 to appear in older people, a new study finds.
They may have confusion with an altered level of consciousness, disorientation, inattention and other mental disturbances, but none of the other typical signs of the coronavirus infection, such as fever and cough, researchers say.
"COVID can operate through multiple ways to affect the brain, including inflammation, mini-strokes, multiple organ system failure, and then, the usual stressors of being sick and hospitalized can contribute to delirium," said senior study author Dr. Sharon Inouye. She is director of the Aging Brain Center at Hebrew SeniorLife and professor of medicine at Harvard Medical School, Beth Israel Deaconess Medical Center, in Boston.
In older patients, delirium is missed in about two-thirds of cases even though it is a common symptom of any severe disease and linked to long hospitalizations, complications and death.
According to Claire Steves, deputy director of TwinsUK, a London-based twin registry that studies complex diseases, "There does seem to be a particular connection between COVID-19 and delirium, which could be due to low oxygen levels, increased inflammatory and immune activation, which has secondary effects on brain functioning, or other changes in blood supply due to sepsis, including changes in brain blood vessels."
In addition, delirium is a common symptom in older people with any new illness, probably because they have a reduced cognitive reserve, she said.
For the study, Inouye's team looked at more than 800 patients aged 65 or older who were seen in the emergency department and diagnosed with COVID-19.
Nearly one-third suffered from delirium when they arrived at the hospital. In 16%, delirium was their main symptom, and 37% of delirious patients had none of the typical COVID-19 symptoms, the researchers found.
Delirium was the sixth most common symptom among the older patients, Inouye said.
"Older adults may not have the typical or expected symptoms of fever, shortness of breath, cough," Inouye explained, "so patients and families must suspect COVID-19 with onset of acute confusion or changes in behavior."
COVID-19 poses a risk at all ages, but older people are at the greatest risk of severe disease, hospitalization, need for intensive care and death. People over 65 years of age represent 16% of the U.S. population and account for more than 80% of these deaths nationwide, the study authors noted.
Steves, who was not involved with the new study, said that her team's research has yielded similar results.
"These findings align very well with our study from U.K. hospitalized older adults, which showed over a quarter of older adults with COVID-19 presenting to hospital had delirium, and the rates were significantly higher in older adults who were frail," she said.
It's critical for health care workers and those who are caretakers of older people to be aware that delirium can be a sign of COVID-19, so that infection controls and treatments can be started, Steves said.
The report by Inouye's team was published online Nov. 19 in JAMA Network Open.
For more about older people and COVID-19, visit the U.S. Centers for Disease Control and Prevention.
SOURCES: Sharon Inouye, MD, MPH, director, Aging Brain Center, Hebrew SeniorLife, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston; Claire Steves, PhD, deputy director (clinical), TwinsUK, and clinical senior lecturer, Kings College London, U.K.; JAMA Network Open, Nov. 19, 2020, online