Eight of 10 hospitalized COVID-19 patients developed neurologic complications and were six times more likely than their peers to die, according to early results from a global study published yesterday in JAMA Network Open.
Many of the conditions were mild to moderate, but half of the patients had altered brain function or structure, and almost one in five were in a coma.
Led by University of Pittsburgh researchers for the Global Consortium Study of Neurologic Dysfunction in COVID-19, the study involved 3,744 hospitalized adult COVID-19 patients at 28 centers in 13 countries from March to October 2020.
Half have acute encephalopathy
Among the patients, 82% reported neurologic symptoms, with 37% having headaches and 26% saying they lost their sense of taste or smell. Clinicians determined that 49% of the patients had acute encephalopathy (diffuse disease that alters brain function or structure), while 17% were in a coma, and 6% had strokes.
The incidence of acute encephalopathy increased with age, from 33% in patients younger than 40 years to 74% in those older than 80. Meningitis and encephalitis (brain swelling and inflammation) were rarely observed (0.5%).
Lead study author Sherry Chou, MD, MSc, said in a University of Pittsburgh news release that acute encephalopathy is by far the most common neurologic issue she sees among COVID-19 patients. "Those patients may be in an altered sensory state or have impaired consciousness, or they don't feel like themselves and act confused, delirious or agitated," she said.
The proportion of patients requiring mechanical ventilation was 21% to 39%, and in-hospital death rates ranged from 14% to 25%.
The strongest predictor of COVID-19 neurologic complications was a preexisting neurologic condition of any kind—including dementia, Alzheimer's disease, and diseases of the brain, spinal cord, and nerves—which were associated with double the risk of coronavirus-related neurologic effects (adjusted odds ratio, 2.23). Likewise, any coronavirus-related neurologic symptoms, ranging from loss of smell to stroke, was tied to a sixfold increase in the risk of death.
"This multicenter cohort study found that neurological manifestations in COVID-19 were highly prevalent and associated with premature mortality," the researchers wrote. "Using a global network with standardized protocols and common data elements is critical to facilitate further studies to understand COVID-19 neurological manifestations, including disease progression, associations with long-term outcomes, pathobiological mechanisms, and societal impact."
'Survivors who need our help'
The researchers studied three different patient groups, including an "all COVID-19" group, which consisted of 3,055 hospitalized coronavirus patients, regardless of neurologic status; a "neurological" group, which consisted of 475 patients with clinically verified neurologic symptoms; and the "ENERGY" (European Academy of Neurology COVID-19 registry) cohort, which included 214 patients evaluated by a consulting neurologist.
All three groups were made up mostly of older, White, overweight patients who had many underlying illnesses such as diabetes, high blood pressure, and previously diagnosed neurologic conditions. Patients who were older, male, or White, or had a high body mass index, were most likely to die.
Chou added that the long-term outlook for COVID-19 patients remains uncertain. "Even if the pandemic is completely eradicated, we are still talking about millions of survivors who need our help," she said. "It is important to find out what symptoms and health problems those patients are facing, and there is still plenty of work for years to come."