Long-haul COVID-19 patients who initially were hospitalized with pneumonia appear to have had more severe impacts on the brain compared with others who also became infected but did not require a trip to the hospital, a study by Northwestern Medicine researchers has found.
The researchers evaluated 600 long COVID patients, most suffering with cognitive difficulties after being infected with the coronavirus between May 2020 and August 2021 — before vaccines were approved in the United States.
The study, published Wednesday in the medical journal Annals of Neurology, followed 100 people hospitalized with COVID-related pneumonia and compared them with 500 who had more mild initial symptoms, including a cough or sore throat. All of them were evaluated in person or remotely via telemedicine at a Northwestern clinic focused on neurological impact of COVID.
The hospitalized patients performed far worse on neurological exams, the Northwestern researchers reported.
Dr. Igor Koralnik, who heads the Northwestern neurological COVID-19 clinic and co-authored the study, said the findings might indicate that the pneumonia patients — many requiring breathing tubes in the hospital — suffered brain damage.
The other patients might have been affected by an autoimmune condition, which occurs when the immune system mistakenly attacks healthy cells.
Koralnik said it’s unclear how many of the 600 patients studied still have long COVID.
He estimated that about one-third of all COVID survivors have long COVID, which can include what doctors call “brain fog,” headaches, loss of taste and smell and dizziness.
COVID-19 complications “will stay with us for the foreseeable future,” Koralnik said. “Long COVID is a pandemic within the pandemic.”
Many researchers around Chicago and across the country are studying long COVID, a condition that so far has raised more questions than it has provided answers.
Most of the patients in the Northwestern study are white women. A key area of future research will focus on racial and ethnic factors at play with long COVID.
Brett Chase’s reporting on the environment and public health is made possible by a grant from The Chicago Community Trust.
