In a recent study conducted by Llados et. al in Spain, it was found that individuals experiencing long-lasting symptoms of Covid-19, now known as Long COVID, may be suffering from damage to the vagus nerve. The vagus nerve is responsible for communication between the body's major organs, including the heart, lungs, and gastrointestinal tract.
The study recruited over 300 individuals who had recently recovered from mild or moderate Covid-19 and were experiencing Long COVID symptoms. Two-thirds of these individuals reported at least one symptom associated with vagus nerve dysfunction, such as persistent cough, difficulty swallowing, increased heart rate, gastrointestinal issues, dizziness, and cognitive complications. These symptoms were more common in individuals with Long COVID compared to those who had fully recovered or were never exposed to the virus.
Ultrasound imaging of the vagus nerve revealed significant thickening in 20% of those reporting Long COVID symptoms. Thickening of the nerve is often a result of inflammatory damage, suggesting that the structural changes observed were likely caused by direct viral infection and immune system activation.
Additionally, the study found that 40% of individuals with Long COVID exhibited flattening of the diaphragm, a muscle responsible for controlling breathing. This was associated with a reduction in lung pressure, explaining symptoms such as shortness of breath and light-headedness. It is important to note that there were no observable abnormalities in the rest of the lungs, suggesting that respiratory symptoms related to Long COVID may be a result of impaired signaling to the diaphragm, rather than direct lung injury.
Damage to the vagus nerve also impacted other vital systems, including heart rate variability, speech, swallowing, and gastrointestinal mobility. These differences were significant compared to individuals who were not exposed to Covid-19 or did not develop Long COVID.
These findings suggest that the vagus nerve may be a potential target for therapeutic interventions to treat Long COVID. Vagal nerve stimulation has been shown to reduce inflammation in the body, and further research into the long-term consequences of vagus nerve injury may provide new insights into the effects of Long COVID on the body. Understanding the impact of Covid-19 on the vagus nerve could lead to improved treatments for those experiencing long-lasting symptoms.