Summary: Neuroimaging study reveals significant brain changes in areas associated with language comprehension, cognition, and circadian rhythm control six months after COVID-19 infection.
Using a special type of MRI, researchers have discovered brain changes in patients up to six months after they recovered from COVID-19, according to a study to be presented next week at the annual meeting of the Radiological Society of North America. (RSNA).
About one in five adults will develop long-term effects from COVID-19, according to the US Centers for Disease Control and Prevention. Neurological symptoms associated with prolonged COVID include difficulty thinking or concentrating, headache, trouble sleeping, lightheadedness, tingling sensation, changes in smell or taste, and depression or anxiety. However, studies have found that COVID-19 may be associated with changes in the heart, lungs, or other organs, even in asymptomatic patients.
As more people become infected with and recover from COVID-19, research has begun to emerge that focuses on the long-lasting consequences of the disease.
For this study, the researchers used susceptibility-weighted imaging to analyze the effects that COVID-19 has on the brain. Magnetic susceptibility denotes how much certain materials, such as blood, iron, and calcium, will become magnetized in an applied magnetic field. This capability aids in the detection and monitoring of a large number of neurological conditions, including microbleeds, vascular malformations, brain tumors, and stroke.
“Cluster-level studies have not previously focused on COVID-19 changes in brain magnetic susceptibility despite several case reports pointing to such abnormalities,” said study co-author Sapna S. Mishra, Ph. d. candidate at the Indian Institute of Technology in Delhi. “Our study highlights this new aspect of the neurological effects of COVID-19 and reports significant abnormalities in COVID survivors.”
The researchers analyzed susceptibility-weighted imaging data from 46 recovered COVID patients and 30 healthy controls. Imaging was done within six months of recovery. Among patients with long-term COVID, the most common symptoms were fatigue, difficulty sleeping, inattention, and memory problems.
“Changes in susceptibility values of brain regions may be indicative of changes in local composition,” Mishra said. “Susceptibilities may reflect the presence of abnormal amounts of paramagnetic compounds, while lower susceptibilities could be due to abnormalities such as calcification or a lack of iron-containing paramagnetic molecules.”
MRI results showed that patients who recovered from COVID-19 had significantly higher susceptibility values in the frontal lobe and brainstem compared with healthy controls. The clusters obtained in the frontal lobe show mainly differences in the white matter.
“These brain regions are linked to fatigue, insomnia, anxiety, depression, headaches, and cognitive problems,” Mishra said.
Portions of the left inferior orbital frontal gyrus (a key region for language comprehension and production) and right inferior orbital frontal gyrus (associated with various cognitive functions, including attention, motor inhibition, and imagination, as well as cognitive processes social) and the adjacent areas of white matter formed the groups of frontal lobes.
The researchers also found a significant difference in the right ventral diencephalon region of the brainstem. This region is associated with many crucial bodily functions, including coordinating with the endocrine system to release hormones, transmitting sensory and motor signals to the cerebral cortex, and regulating circadian rhythms (the sleep-wake cycle).
“This study points to serious long-term complications that the coronavirus can cause, even months after recovery from the infection,” Mishra said. “The present findings are from the small time window. However, longitudinal time points over a couple of years will clarify whether there is any permanent change.”
The researchers are conducting a longitudinal study in the same cohort of patients to determine if these brain abnormalities persist over a longer period of time.
Coauthors are Rakibul Hafiz, Ph.D., Tapan Gandhi, Ph.D., Vidur Mahajan, MBBS, Alok Prasad, MD, and Bharat Biswal, Ph.D.
About this research news in neurology and COVID-19
Author: linda brooks
Contact: Linda Brooks–RSNA
Image: Image is credited to RSNA and Sapna S. Mishra.
original research: The findings will be presented at the 108th Scientific Assembly and Annual Meeting of the Radiological Society of North America.