Columbia researchers uncover COVID-19’s impact on brain

The team's findings suggest inflammation may trigger neurologic damage but the virus' long-term impact on memory and mood is still unknown.
By: | April 22, 2021
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Higher education institutions have played a critical role in assisting on the front lines and behind the scenes during the COVID-19 pandemic. From vaccine development to clinic rollouts to research around the novel coronavirus, scientific and medical developments have paved the way for strategic decisions to be made on campuses, in communities and across the globe.

Some of those breakthroughs not only have helped in the moment but also will provide a working base for further discoveries and planning, around this crisis and others in the future.

Late last week, in the publication Brain, a neurology team at Columbia University’s Vagelos College of Physicians and Surgeons revealed major findings in studies done at Irving Medical Center/New York Presbyterian Hospital. In more than three dozen patients who had contracted the virus and died, all of them had sustained “significant” neurologic effects from SARS-COV-2.

“We observed many pathological changes in these brains, which could explain why severely ill patients experience confusion and delirium and other serious neurological effects, and why those with mild cases may experience ‘brain fog’ for weeks and months,” said Dr. James Goldman, professor of pathology and cell biology in psychiatry, who led the study along with professors Dr. Peter Canoll and Dr. Kiran Thakur.

They also made another important discovery.

“There’s been considerable debate about whether this virus infects the brain, but we were unable to find any signs of virus inside brain cells of more than 40 COVID-19 patients,” Goldman said.

Inside the report

The study was conducted on 41 patients age 38 to 97 who had been hospitalized before losing their battles to COVID-19. Some died soon after being admitted, while others passed away after months of fighting the virus. Researchers noted that about half of the patients had been intubated. In addition to the damage done to the brain, they all experience lung damage, one of the hallmarks of COVID-19.

“The first thing we noticed was a lot of areas with damage from a lack of oxygen,” Goldman said. “They all had severe lung disease, so it’s not surprising that there’s hypoxic damage in the brain.”

Researchers noted that blood clots likely caused the hypoxic damage. In addition, Canoll said microglia, or dormant immune cells in the brain that can be triggered by diseases, were seen often in patents. It is likely the inflammation throughout the body caused those cells to be activated, “so even without directly infecting brain cells, COVID-19 can cause damage to the brain,” he said.

One concern is the potential long-term effects of those who have gotten the virus and the length of time their bodies may have been fighting COVID-19. Since they were found mainly in the lower brain stem area, could the movement of microglia affect memory and mood?

“We know the microglia activity will lead to loss of neurons, and that loss is permanent,” Goldman says. “Is there enough loss of neurons (in the hippocampus) to cause memory problems? Or in other parts of the brain that help direct our attention? It’s possible, but we really don’t know at this point.”

So, Columbia researchers will continue to study patterns. They are currently looking at those who recovered from COVID-19 but then passed away as well as patients who had pre-existing respiratory issues to determine “how much of COVID-19 brain pathology is a result of the severe lung disease.”