People who have been under the care of a neurologist, for anything from a stroke to Parkinson’s disease to chronic migraines, have a substantially elevated risk of dying from COVID-19. That’s the top takeaway from the largest study to date on the relationship between neurological problems and severe COVID-19 (the kind that puts people in the hospital). Such patients should take extra care to avoid COVID-19 infections, and should be vaccinated as soon as they can, says study author Sherry Chou, a critical care neurologist at the University of Pittsburgh Medical Center.
The study of more than 3,700 patients in 13 countries began in March 2020, as doctors were just beginning to appreciate that COVID-19 was not simply a respiratory infection but had a wide range of manifestations. “We had many critical knowledge gaps,” says Chou, who presented the initial study findings virtually at the recent annual meeting of the American Academy of Neurology, or AAN. She heads the Global Consortium Study of Neurologic Dysfunction in COVID-19, a collaboration that now includes more than 200 medical centers in more than 30 countries. The consortium studies both short- and long-term neurological implications related to COVID-19, and assesses the effectiveness of treatments.
It’s vital to get a handle on COVID’s neurological effects to understand the magnitude of the pandemic’s potential impact, Chou says, because brain and nerve issues, regardless of the cause, tend to be both highly disabling and difficult to recover from. “It’s generally easier to recover from respiratory or heart problems, and you have a reasonable chance of returning to home life faster compared with stroke or nerve damage,” she says.
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The study, the first major one out of the collaboration, analyzed data on three groups, or cohorts. The largest included more than 3,000 patients representing all COVID-19 admissions in the participating hospitals. Two smaller groups consisted of patients who had been specifically identified as having neurological conditions, either preexisting or due to COVID-19. The study collected information on COVID-19 symptoms (reported by the patient) and signs (observed by clinicians or confirmed with tests or medical imaging). Across the three groups, 4 in 5 patients had some type of neurological sign or symptom during their COVID-19 hospital stay. Of self-reported symptoms, more than 1 in 3 patients had headaches and about 1 in 4 had lost their sense of smell and/or taste.
Far more dangerous than self-reported symptoms were neurological signs, such as delirium, confusion or coma. Hospitalized patients with these clinically confirmed neurological signs of COVID-19 — about half of the patients in the study — were up to six times more likely to die in the hospital than patients who didn’t show those signs. The study also found that patients with preexisting neurological conditions were more likely than others to develop these clinically confirmed COVID-specific signs.
“This is a solid study,” says Dr. Natalia Rost, who heads the stroke division of the neurology department at Massachusetts General Hospital in Boston and teaches at Harvard Medical School. (Though Mass General participated in the study, Rost was not directly involved.) Neurologists have been handicapped since the pandemic began by their inability to predict who’s going to develop complications, Rost says. “This gives us data to say that if you have a neurological disorder already, you are at high risk of additional neurological injury with COVID.”
That knowledge can help clinicians choose more effective and/or less dangerous treatments for patients at higher neurological risk, Chou says. For example, many COVID-19 patients respond well to high-dose steroids for their respiratory symptoms, but those treatments can cause agitation and might pose extra risks to patients who have neurological conditions.
The large number of patients in the study offsets the conditions under which the information was collected between March and October 2020, when hospitals and providers were overwhelmed by COVID-19, Rost adds. The research protocol was designed to make things as easy as possible for the embattled staff in emergency rooms and at hospital bedsides. It simply required them to ask whether patients had any preexisting neurological conditions — yes or no — though some providers made notes about the details of those conditions, which could range from diseases like Parkinson’s, Alzheimer’s or multiple sclerosis, to a history of stroke or seizures, to chronic migraine headaches.
Providers also asked patients whether they were experiencing any neurological symptoms that were typical of COVID-19, including its signature loss of taste and smell, headache and fainting. And finally, the study collected data on those neurological signs of COVID-19 — such as delirium, coma and stroke — that could be confirmed through clinicians’ observations, diagnostic imaging and other tests.
The study showed that patients with any kind of preexisting neurological condition when they were admitted to the hospital with severe COVID-19 were more than twice as likely as other patients to develop additional neurological complications. The most common one across all the patients was acute encephalopathy (reported in 49% of patients), a general term for a range of conditions including delirium, confusion and “brain fog.” The second most common was coma, in 17% of patients.
Doctors have long known that viruses can have dire impacts on brain and nervous system function, Chou says, citing a syndrome called “encephalitis lethargica” or “sleeping sickness” that afflicted up to 5 million people in the years following the 1918 flu pandemic. Patients suffered from a variety of symptoms including extreme fatigue, and many later developed muscle spasms, stiffness and weakness similar to Parkinson’s disease. The science back then was inadequate to determine the exact cause of the condition, its relationship to the flu infection or how to treat it effectively.
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“Our tools are lots better now,” and the data from studying COVID-19 patients may enable major breakthroughs in treating post-viral syndromes generally, says Chou, whom U.S. News profiled in 2020 as part of its ongoing Hospital Heroes series.
The frequency of neurological complications due to COVID-19 is extremely concerning, she adds. “At the beginning I hoped they would be rare because the impact would be astronomical if they weren’t,” she says. “Even a rare event multiplied by a hundred million is no longer a minor problem, and these (complications) can cause long-term disability.”
The study did contain a little bit of good news. Rost, who chairs the AAN’s science committee, says neurologists feared COVID-19 might directly attack the brain (encephalitis) or nerves ( meningitis), but those effects turned out to be among the rarest, affecting less than 0.1% of patients in the large “all-COVID” group.
Strokes in COVID-19 patients also received a lot of press, because they were often catastrophic and because they occurred in younger patients with no history of neurovascular problems. Both Chou and Rost say they were relieved that strokes were not the most common neurological effect seen in the study. Strokes affected 6% of the patients overall — 3% of the large “all-COVID” cohort, and almost 20% of the two smaller cohorts of patients with neurological conditions.
The initial findings are schedule to be published soon in a peer-reviewed medical journal. The consortium plans to expand its studies to examine the neurological impact of COVID-19 on children and to study COVID’s long-term effects in more depth.
There are still plenty of unanswered questions, Rost says. Collecting more uniform and complete data on each patient, including MRI scans and detailed medical histories, will expand and refine these findings. “In the future, we will have the luxury of being prepared,” she says. “If anyone shows you a perfect study and says it was done during 2020, you should beware of those findings.”
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People With Neurological Conditions At Greater Risk of Death by COVID-19 originally appeared on usnews.com