Abnormalities can be seen in the brains of COVID-19 survivors up to six months after recovery, according to new research. The team, led by scientists from the Indian Institute of Technology in Delhi, used a special type of magnetic resonance imaging (MRI) to look at brain changes caused by infection with SARS-CoV-2, the virus behind COVID-19.
Susceptibility weighted imaging (SWI) is a relatively new MRI technique. It works by taking advantage of the different responses of certain materials – such as blood components, calcium, and iron – when they are exposed to a magnetic field. SWI is particularly useful for identifying and locating brain hemorrhages, vascular malformations, and tumors.
"Group-level studies have not previously focused on COVID-19 changes in magnetic susceptibility of the brain despite several case reports signaling such abnormalities," said study author Sapna S. Mishra in a statement. “Our study highlights this new aspect of the neurological effects of COVID-19 and reports significant abnormalities in COVID survivors."
The US Centers for Disease Control and Prevention (CDC) estimates that one in five adults who are infected with SARS-CoV-2 will experience some long-term symptoms. A lot of research has begun to focus on these potential lasting effects, as more and more people are catching and recovering from COVID-19.
Studies have reported changes in the lungs, heart, and other organs, but many of the symptoms reported by those with long COVID appear to be neurological in nature – things like brain fog, headaches, dizziness, and even anxiety and depression.
The team analyzed imaging data from 46 people who had recovered from COVID-19 within the preceding six months, comparing this to data from 30 healthy controls. Of the patients with long COVID, the symptoms they most frequently reported were fatigue, sleep disturbances, lack of attention, and memory problems.
The results showed that the COVID survivors had significant abnormalities in a number of frontal lobe white matter regions, including the left and right orbital inferior frontal gyri.
"These brain regions are linked with fatigue, insomnia, anxiety, depression, headaches and cognitive problems," said Mishra.
There were also atypical readings in the right ventral diencephalon region of the brain stem. Many essential functions are controlled by the brain stem; of particular relevance to long COVID research is the fact that this region is associated with regulation of the sleep-wake cycle.
Summing up the findings, Mishra said, "This study points to serious long-term complications that may be caused by the coronavirus, even months after recovery from the infection.”
The researchers now plan to undertake a longitudinal study on the same group of COVID-19 survivors, to see if these brain abnormalities are persistent over longer time periods.
The study is due to be presented at the 2022 annual meeting of the Radiological Society of North America.