A pre-existing neurological condition strongly predicts that a patient with COVID-19 will develop additional neurological woes, according to a large new study. Those pre-existing conditions include dementia and Alzheimer’s disease, the researchers said.

The Global Consortium Study of Neurologic Dysfunction in COVID-19 spanned 133 adult healthcare institutions across the globe. It also found that people with COVID-19-related neurological symptoms, from the loss of smell to major events such as stroke, have a six-fold higher risk of in-hospital mortality from the virus. These survivors may in turn face a need for ongoing post-acute care, the researchers say.

In one study group of more than 3,700 hospitalized adult patients with COVID-19, for example, 82% had self-reported or clinically diagnosed neurological symptoms. Many patients reported having headaches and losing their senses of smell or taste. Clinicians also observed acute encephalopathy, inflammation of the brain that can temporarily alter cognitive functioning, in half of the patients. Coma affected 17% of patients, and 6% experienced a stroke, the authors reported.

These survivors’ health problems may be with us for some time, said lead author Sherry Chou, M.D., M.Sc., of the University of Pittsburgh Medical School. 

“Even if the pandemic is completely eradicated, we are still talking about millions of survivors who need our help,” Chou 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.”

The study was published Tuesday in JAMA Network Open.