Brain Dopamine Damage in Long COVID Proven by PET Scans

New brain imaging research has revealed, in the clearest way to date, the damage that long COVID causes to the brain's dopamine system. Using positron emission tomography (PET), scientists examined dopamine-secreting neurons in the brains of long COVID patients. These detailed scans hold the potential to explain the biological root of persistent symptoms such as fatigue, slowed movements, lack of motivation, and memory issues. The findings prove a marked reduction in the density of dopamine nerve endings in key regions of the brains of individuals experiencing long COVID. While this helps us understand the core mechanisms underlying the neurological complaints experienced by patients, it also establishes a new target for future treatments.

The detailed research was conducted by researchers at the Centre for Addiction and Mental Health (CAMH) in Kanada and published in eBioMedicine, one of the leading scientific journals. Scientists used specialized PET imaging to compare the dopamine neuron integrity of individuals diagnosed with long COVID with participants in a healthy control group. It was discovered that in the brains of long COVID patients included in the study, dopamine levels were significantly lower in the striatum region, which is the center of motivation, movement, learning, and cognitive functions. This signal loss is considered physical proof that dopamine-secreting neurons have been directly damaged. The data obtained paves the way for the development of treatment strategies aimed not only at alleviating symptoms but also at stopping permanent neurological damage.

Long COVID has become one of the most common chronic disorders to emerge from the pandemic, affecting approximately nine million adults in the ABD and about five percent of the global population. This condition manifests itself with symptoms that persist for at least three months following the initial SARS-CoV-2 infection, including brain fog, memory loss, and mood changes. Despite the disease being so widespread, there is currently no evidence-based specific treatment method available because the biological mechanisms triggering these symptoms are not fully understood. However, this new imaging study fills a major gap in the field by uncovering the physical causes underlying the disease. Thus, it is emphasized that this condition, which makes life difficult for millions of people, should now be recognized not merely as psychological but as a functional neurological disorder.

The imaging results are also in perfect alignment with the clinical symptoms of the patients. Researchers observed a direct connection between low dopamine markers in the ventral striatum region and the severe loss of motivation seen in patients. Similarly, dopamine reduction in the dorsal putamen region was found to be directly related to slowed movements, while the decline in the caudate nucleus was directly linked to poorer memory performance. This model reveals that damage in specific regions of the dopamine system can directly trigger the various neurological symptoms experienced by long COVID patients. Furthermore, the team drew attention to the fact that inflammation could be the primary factor triggering cellular damage, recalling that in their previous studies, they detected high levels of inflammation in brain regions rich in dopamine-producing neurons in long COVID patients.

These groundbreaking findings indicate that long COVID research should not be limited to inflammation-focused treatments alone. Classifying the disease, at least partially, as a disorder affecting the brain's dopamine system has the potential to completely transform treatment processes. Currently, there are many approved drugs used in the treatment of other neurological diseases that increase dopamine levels or strengthen dopamine signaling. Researchers believe these existing drugs or dopamine precursors could be repurposed to alleviate long COVID symptoms. In this regard, scientists plan to start a clinical trial soon with the University Health Network (University Health Network) to test the efficacy of these relevant treatment methods. This study could pave the way for the first mechanism-based treatment methods that will eliminate fatigue and memory issues while validating the experiences of patients whose complaints have been dismissed for years.