Long COVID symptoms not ‘all in the head’

Researchers have found new evidence linking COVID-19 and changes to the brain.

A recent survey has shown that at least two thirds of all Australians have had COVID-19 and in the US figures suggest that around one in five adults will develop long-term effects from infection.

Long COVID’ effects can include lasting neurological issues, as well as changes to vital organs such as the heart and lungs, even when the original COVID-19 infection was asymptomatic. Sufferers of long COVID often report trouble sleeping, difficulties concentrating or thinking, changes in mood (such as heightened levels of depression or anxiety) and complications like headaches, light-headedness, pins and needles and changes in the sense of smell or taste.

Now, researchers have found evidence for significant changes in parts of the brain that may correspond to many of the most common neurological symptoms.

Using a specialised type of MRI scan known as ‘magnetic susceptibility’ researchers compared the brains of 46 patients up to six months after they have recovered from COVID-19 with a control group of 30 healthy participants.

Long covid mri scans
MRI scans showing changes in the brains patients post-recovery from Covid-19. Three significant clusters were found primarily in the white matter regions of the pre-frontal cortex and in the brainstem.

Magnetic susceptibility is often used to detect and keep an eye on other conditions like microbleeds, tumours and strokes.

“Our study highlights this new aspect of the neurological effects of COVID-19 and reports significant abnormalities in COVID survivors,” said study co-author Sapna S. Mishra, a Ph.D. candidate at the Indian Institute of Technology in Delhi.

Read more: As a pre-Christmas COVID wave gets under way, experts warn virus isn’t mild, and isn’t over

Although there have been reports on abnormalities in magnetic susceptibility of the brain post-COVID-19 recovery, there has so far been little research on it.

Diagram of human brain
Different regions of the brain are associated with different functions. Credit: eli_asenova/Getty Images

These ‘abnormalities’ include significant changes in the parts of the frontal lobe and brain stem. Affected parts of the frontal lobe are associated with understanding and forming language, cognitive functions such as attention, motor inhibition and imagery, as well as social cognitive processes, while changes in the brain stem were in regions associated with systems controlling hormone regulation, sensory relay and maintaining circadian rhythms.

“These brain regions are linked with fatigue, insomnia, anxiety, depression, headaches and cognitive problems,” Mishra said. “This study points to serious long-term complications that may be caused by the coronavirus, even months after recovery from the infection.”

At this stage, the study only provides a snapshot of patients up to 6 months post-recovery, although the research team plan to continue monitoring the patient cohort.

“The present findings are from the small temporal window,” said Mishra. “However, the longitudinal time points across a couple of years will elucidate if there exists any permanent change.”

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