Even Mild Covid-19 Can Sometimes Cause Hallucinations and Other Brain Problems

A picture of a human brain taken by a positron emission tomography scanner, also called a PET scan.
A picture of a human brain taken by a positron emission tomography scanner, also called a PET scan.
Image: Fred Tanneau (Getty Images)

Doctors are starting to see the sort of serious brain problems that scientists had previously warned would become more common because of the covid-19 pandemic. A new study published Wednesday details patients who caught the coronavirus and went on to develop neurological complications, including cognitive impairment, trouble moving or walking, and frightening hallucinations and delusions. These symptoms happened even in people with mild covid-19.

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As early as April this year, some researchers warned about a potential wave of neurological illness caused by covid-19, mostly based on what they knew about past pandemics and other viral infections like the flu. At the time, there were already isolated case reports of people with neurological symptoms that began during or after they became sick with covid-19. More reports have come out since, including in children who develop a rare inflammatory condition linked to the coronavirus.

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This latest study, published in the journal Brain, appears to offer the most extensive look yet at these complications in adults who get covid-19.

The authors studied the cases of 43 people with confirmed or suspected covid-19 who were referred to a large hospital in the UK that specializes in neurological problems. The patients were between the ages of 16 and 85 and ranged in the severity of their other covid-19 symptoms. Their neurological symptoms included delirium (a period of severe mental confusion that often arrives rapidly), psychosis, stroke, seizures, and face or limb muscle weakness, among others. In brain scans, there was evidence of swelling, hemorrhaging, and other damage to various parts of the brain.

Many of the cases also developed a rare condition known as acute demyelinating encephalomyelitis, or ADEM. ADEM is characterized by a brief but potent burst of inflammation that attacks the outer layer of myelin that surrounds nerve fibers. While some neurological symptoms did appear more frequently in people with severe respiratory covid-19, severity didn’t predict the odds of getting ADEM in these cases. Even relatively mild cases of covid-19 led to frightening episodes of neurological illness.

In one particularly startling example, a 55-year-old woman had been admitted to the hospital with many of the classic symptoms of covid-19, including fever, trouble breathing, and a loss of smell. Once there, she only needed minimal oxygen support and was discharged three days later in seemingly good health. The next day, her husband reported that she was disoriented and behaving oddly, such as putting on and taking off her coat repeatedly. The woman then reported visual and auditory hallucinations, including seeing lions and monkeys in the house. She also grew paranoid and developed Capgras delusion, in which a person feels like their loved ones have been replaced by identical strangers, which progressed to aggression toward her family and hospital staff.

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Though her disorientation did go away, her psychiatric symptoms remained. At the time of the study’s publication, the doctors reported that her condition had been improving over a three-week course, with the help of antipsychotic medications.

Neurological symptoms linked to viral infections tend to be rare in general, and there doesn’t seem to be strong evidence right now that the coronavirus itself regularly invades the nervous system, which would be especially worrying. But in the context of a newly emerged pandemic that has already infected millions and will likely sicken many more before a vaccine or highly effective treatment is available, that leaves a lot of potential victims who will have to deal with these sometimes lifelong complications, even if they only experience mild illness otherwise.

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Science writer at Gizmodo and pug aficionado elsewhere

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DISCUSSION

xedous6
thisisnotmyname

Do we know how this compares to other viruses and their effect on the brain? Not trying the downplay the seriousness, but it is worse/better/on par? Just want to make sure I prioritize correctly in the things I should panic over.