In a scientific development that could change the way long COVID is understood and treated, a new study has revealed that encephalitis is not the primary cause of the persistent symptoms suffered by millions after contracting COVID-19.
The study, conducted by the University of Turku in Finland and published in the Journal of Neurology, used advanced brain imaging techniques to examine patients with long-term symptoms such as fatigue, brain fog, anxiety, and depression.
The researchers compared three groups: 14 patients with long COVID, 11 healthy individuals, and 13 people with multiple sclerosis (a neurological disease known to cause inflammation in the brain).
Everyone underwent advanced brain scans, as well as blood tests to look for signs of nerve cell damage.
The result was surprising, as the researchers found no evidence of widespread inflammation in the brains of long-term COVID patients compared to healthy individuals.
When compared to patients with multiple sclerosis, inflammation in the white matter of the brain was significantly less in the long COVID group.
The study also identified another important finding: patients who were tested within 16 months of contracting COVID-19 showed higher levels of inflammatory activity compared to those who had been ill for a longer period.
Professor Laura Airas, the research team leader, says: "This suggests that inflammation may be more pronounced in the early stages of the disease, and then gradually recede over time."
The most profound discovery was in brain regions associated with emotion and memory. Researchers found that long-term COVID patients with higher levels of anxiety and depression, as well as a poorer quality of life, showed increased activity in the hippocampus and amygdala. These two brain regions are responsible for memory, emotional regulation, and the stress response.
This means that the severity of symptoms in some patients may be related to a malfunction in the brain's processing of emotions and stress, and not necessarily to ongoing inflammation.
These findings change scientists' view of long COVID, from a state of "chronic encephalitis" to a more complex condition, where inflammatory changes are stronger at the beginning and then subside, while symptoms related to anxiety, depression, and fatigue remain.
Most importantly, the study opens the door to changing treatment strategies.
The researchers suggest that some long-term COVID patients may benefit more from treatments that focus on stress management and emotional regulation (such as psychotherapy and behavioral therapy), rather than treatments that only target reducing inflammation (such as anti-inflammatory drugs).
Professor Ayras explains: "This study highlights the need to continue investigating the complex biological mechanisms underlying long COVID. Understanding these processes is essential for developing targeted therapies."
Long COVID remains a major global health problem, affecting millions of people worldwide whose symptoms may persist for months or even years after their initial infection. This study represents an important step toward a better understanding of this complex condition and is guiding researchers toward new treatment approaches that focus not only on inflammation but also on mental health and stress management.
