A Canadian study published in eBioMedicine reveals long COVID patients have 18% fewer dopamine nerve endings in the brain’s striatum, linking the condition to lasting damage in the dopamine system, according to ScienceAlert and medscape.com.
Brain imaging studies have uncovered a troubling link between long COVID and lasting damage to the brain’s dopamine system, a discovery that could reshape how the condition is understood and treated. The research, led by Jeffrey Meyer, found that individuals with long COVID exhibit significantly reduced dopamine nerve endings in the striatum, a brain region critical for motivation, movement, and cognition.
Brain Imaging Reveals Dopamine System Damage
The study, published in eBioMedicine, used positron emission tomography (PET) scans to compare 24 adults with long COVID to 24 healthy controls. Researchers observed lower levels of vesicular monoamine transporter 2 (VMAT2), a biomarker for dopamine nerve terminals, across all major regions of the striatum in long COVID patients. This reduction was associated with symptoms like fatigue, slowed movement, and memory issues. What cannot be seen is too often considered uncertain,
wrote nuclear medicine researcher Eric Guedja and neuroscientist Danielle Beckman in a commentary accompanying the study.
The damage was detected even in patients who had lived with long COVID for up to 4.6 years, suggesting the effects are not temporary. This is the first study to investigate the integrity of dopaminergic neurons in long COVID,
said Meyer, who noted that dopamine-releasing neurons have high concentrations of ACE2 receptors, potentially making them vulnerable to SARS-CoV-2. The findings align with earlier research showing brain inflammation and structural changes in long COVID patients, but this study specifically ties those changes to the dopamine system.
Dopamine Loss Linked to Specific Symptoms
The study identified distinct correlations between dopamine nerve damage and specific symptoms. Lower VMAT2 levels in the ventral striatum were linked to reduced motivation, while deficits in the dorsal putamen correlated with slower movement. Damage to the caudate nucleus was associated with memory difficulties, including delayed verbal recall.
These results build on earlier work by the same team, which found that long COVID is associated with gliosis and inflammation in the striatum. The new study suggests that dopamine system impairment may underlie many of the condition’s neurological symptoms. Understanding the mechanism is critical for developing targeted treatments.
Potential Treatments and Ongoing Research
The discovery opens new avenues for treatment.
However, challenges remain. Long COVID affects an estimated 5% of the global population, with no standardized diagnostic tools or evidence-based treatments.
The research also highlights the broader implications of long COVID. The study’s findings could influence future guidelines for diagnosing and treating long COVID, particularly in cases involving neuropsychiatric symptoms.
What Comes Next for Patients and Researchers
The study’s authors stress that while the sample size was small, the results are significant enough to warrant further investigation.
For patients, the findings offer a glimmer of hope. As the medical community continues to unravel the complexities of long COVID, the dopamine system’s role may prove to be a critical piece of the puzzle. With more research and targeted interventions, the goal is to improve outcomes for the millions affected by this persistent condition.
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