No widespread brain inflammation found in long COVID patients, study finds
A new study using advanced brain imaging has found no evidence of widespread brain inflammation in patients with long COVID compared to healthy individuals, challenging some assumptions about the condition's neurological underpinnings.
Researchers at the University of Turku in Finland compared PET and MRI scans of 14 people with long COVID, 11 healthy controls, and 13 multiple sclerosis patients. Long COVID patients showed significantly lower inflammatory activity in white matter than multiple sclerosis patients.
The study, published in the Journal of Neurology, found no differences in markers of brain inflammation or neurodegeneration between long COVID patients and healthy controls.
However, the findings revealed a different pattern in emotion-related brain regions. Higher levels of depression, anxiety, and lower quality of life were associated with increased cellular activity in the hippocampus and amygdala.
"Altered cellular activation in emotion-regulating brain regions may be linked to symptom severity in some patients."
The timing of infection appeared to matter. Individuals scanned within 16 months of their initial COVID-19 infection showed higher white matter inflammatory activity compared to those with longer disease duration.
The researchers suggest this pattern indicates that brain inflammation may be more prominent early after infection and decrease over time.
Rather than supporting broad anti-inflammatory treatments, the study's authors propose that treatments targeting stress and emotional regulation may be more beneficial for some patients.
Key findings at a glance:
- No widespread brain inflammation detected in long COVID vs. healthy controls
- Lower inflammatory activity than in multiple sclerosis patients
- Emotional symptoms linked to activity in hippocampus and amygdala
- Inflammation may be higher in early stages, then decrease