"Eight out of 10 people don't know what encephalitis is. And we need to change that," Dr. Ava Easton, CEO of the Encephalitis Society, said.
"Encephalitis has a high death rate. Unfortunately, in many of those who survived the condition, they're left with an injury to the brain," Easton said.
New research looks at brain mapping of COVID patients and found the neurological symptoms aren’t caused by the coronavirus directly invading the brain, but instead part of a set of bodily reactions from COVID-related inflammation.
"You get the really, really bad pneumonia because you're getting so much inflammation in your lungs. So the same thing happens in the brain," Omar Siddiqi, an assistant professor of neurology at Harvard Medical School, said.
There are still some unknowns: where exactly in the brain COVID-related inflammation happens. But one thing that is known: what symptoms look like.
"Mild disorientation and problems with word-finding, all the way up to being comatose in the most serious forms," Siddiqi said.
Another big unknown: exactly how many COVID patients are impacted by encephalitis. One San Francisco expert who specializes in neurology and infectious diseases told me it's a minority.
"But it's hard to put an exact number on it," said Michael Wilson, associate professor of neurology at the University of California San Francisco.
Patients are often treated with anti-inflammatory or antiviral drugs. And experts say encephalitis is easy to spot with clinical tests like MRI and spinal taps.
"COVID patients, because they have so many other problems, they don't get spinal taps, like, right away. Like, it might be, like, two weeks into their hospitalization,"Wilson said.
Experts are calling for more awareness and testing, but those tests aren’t cheap, and often not a priority when a COVID patient is hospitalized.
"If you actually don't recognize it quickly, that can cause a lot of damage and cause cognitive impairment, among other things, and even death," Siddiqi said.