A new brain imaging study has upended a longstanding assumption about long COVID, finding no evidence of widespread brain inflammation in patients with prolonged symptoms. The study, published in ScienceDaily, instead points to increased brain activity in regions tied to mood and emotion as the strongest correlate of severe cases.
The findings challenge the prevailing hypothesis that neuroinflammation drives the cognitive fog, fatigue, and other neurological complaints seen in many long COVID patients. Researchers had widely assumed inflammation was a key mechanism, prompting numerous clinical trials of anti-inflammatory drugs.
According to the study, the most debilitating symptoms were associated not with inflammation markers but with hyperactivity in areas such as the amygdala and prefrontal cortex. These regions are central to processing emotions like anxiety and depression, suggesting a potential shift in understanding the disorder's underlying biology.
If confirmed, the results could redirect therapeutic approaches away from anti-inflammatory treatments and toward interventions targeting mood regulation, such as cognitive behavioral therapy or neuromodulation. Patients currently enrolled in inflammation-focused trials may need to reconsider their options.
The study's authors caution that the findings are preliminary and require replication in larger, more diverse cohorts. Some experts note that the absence of detectable inflammation does not rule out other neuroimmune processes at work, given the limitations of current imaging resolution.