We investigated the risk of PD in patients who underwent vagotomy, and hypothesized that truncal vagotomy is associated with a protective effect, while super-selective vagotomy has a minor effect.
I wonder whether this reduction in Parkinson's incidence is due to the fact that the vagus nerve is the main route for carrying inflammatory signals from the body peripheries (like the gut) into the central nervous system (CNS), because in the CNS, these inflammatory signals trigger the release of pro-inflammatory cytokines from microglial cells in the brain.
So if the vagus nerve is cut, these inflammatory signals from peripheral locations like the gut may not reach the brain, meaning that the overall level of inflammation in the brain may be reduced, especially in people with some mild chronic gut inflammation. This reduction of brain inflammation due to a cut vagus may conceivably be the factor that protects against the development of Parkinson's disease, as brain inflammation releases several toxic factors such as superoxide.
I wonder what would happen if you performed a truncal vagotomy on an ME/CFS patient. Might cutting the vagus nerve in this way cure or improve ME/CFS? Michael VanElzakker thinks that inflammatory signals traveling along the vagus nerve to the brain are the cause of ME/CFS symptoms, by virtue of the fact that these inflammatory signals will ramp up brain inflammation and instigate sickness behavior.
If VanElzakker's theory is right, then blocking these signals from traveling along the vagus could be an effective treatment for ME/CFS.
I have often thought that using a local anesthetic (by injection) on the vagus, to temporarily block the inflammatory signals sent along this nerve, might be a very interesting experiment to perform on an ME/CFS patient. Would temporarily anesthetizing the vagus nerve, just like a dentist does to the nerves in your mouth, make ME/CFS symptoms disappear for a few hours?
I can't imagine it would be difficult to anesthetize the vagus nerve. Provided the vagus nerve was only anesthetized below the heart (so that heart function is not affected), then I would think this should be safe. It would be like a temporary truncal vagotomy. If temporarily anesthetizing the vagus helped ME/CFS, then a permanentl truncal vagotomy might be considered.
It would also be interesting to know if the incidence of ME/CFS is lower in patients that have had truncal vagotomy. If so, this would tend to indicate the involvement of the vagus nerve in generating ME/CFS symptoms.
Dr John Chia has shown
† that 82% of all ME/CFS patients have a chronic enterovirus infection of the
parietal cells of the stomach (the stomach acid-secreting cells). Now it just so happens that the vagus nerve is directly connected to these parietal cells (since the vagus helps activate these cells to release stomach acid). This chronic enterovirus infection could be sending inflammatory signals to the brain via the vagus, giving rise to the symptoms of ME/CFS.
