Researchers at a major university hospital in Catalonia have identified vagus nerve dysfunction as a central factor in the development of long-term COVID symptoms. The findings were shared in a science journal where the paper was initially available as a preprint before undergoing formal peer review and publication.
In the study, scientists compared the structure and function of the vagus nerve in people with lingering COVID symptoms to those who recovered fully. The vagus nerve influences several critical body systems, including the throat, voice box, heart, lungs, and digestive tract.
Individuals with long-term COVID showed a higher incidence of symptoms linked to vagal dysfunction. Notably, the researchers observed changes associated with impaired vagal signaling and reported that in about six in ten patients the diaphragm, a dome-shaped muscle essential for breathing, tends to flatten. This observation may help explain why some patients experience shortness of breath even when lung tests appear normal.
These results emphasize the potential importance of vagal dysfunction in the onset and persistence of long-term COVID. The data could lead to improved methods for diagnosing and treating these symptoms, and the team suggests future work to determine whether using vaginal nerve ultrasound techniques at different stages of the illness might yield distinct outcomes for early versus late disease. (citation: Lancet preprint)
Long-term COVID-19 affects a notable portion of people who survive the acute infection, with estimates ranging from about 5 to 10 percent. All participants in the study reported at least one ongoing symptom associated with the condition, such as voice or swallowing difficulties, shortness of breath, rapid heartbeat, coughing, dizziness or fainting upon standing, gastrointestinal issues, or challenges with mental functions.
The report points to the possibility that ancient research questions about nerve pathways and blood flow may intersect with modern respiratory and neurological findings. For example, in cases where carotid arteries are significantly narrowed, intense physical exertion can raise the risk of stroke, highlighting the interconnected nature of vascular and nervous system health.