The Vagus Nerve Hypothesis is an interesting look at what might be causing the main symptoms of CFS and Fibromyalgia. The hypothesis states:
“While the sensory vagus nerve normally signals the body to rest when it senses a peripheral infection, that fatigue signal is pathologically exaggerated when an infection is located on the vagus nerve itself”
This hypothesis was put forth by Michael VanElzakker, a neuroscientist at Tufts University. His theory is that we’ve too long been looking for a central viral cause of these disorders, when the real issue is not what, but where. So the theory is that basically it doesn’t matter what the virus is, what matter is is that the virus is located on the vagus nerve.
He says that glial cells (which are neuroimmune cells) will respond the same way to any infection, yet when the infection is in the vagus nerve that response is amplified, causing the brain to over-react with increased sickness behavior (fatigue, fever, sleep changes, pain, appetite changes, etc.) This creates a behavior loop where the sickness behavior causes the glial cells to continue to react as if an infection is present creating more sickness behavior.
He points out that neurotropic viruses (the Herpes family of viruses and others) – viruses that affect nerve tissue- have been most commonly associated with CFS. Yet, obviously not everyone who has one of these viruses develops CFS or related disorders. Thus, the difference is where the virus is located. Since these viruses can infect any nerves, he suggests that it’s only when the virus infects the vagus nerve directly that the reaction is so intense.
This is an interesting hypothesis, but keep in mind that this is all speculation on the part of Dr. Vanelzakker, but there’s a lot about this hypothesis that makes sense. The trick now is in proving it and then finding a way to reverse the problem.
If you’d like to read more about this hypothesis I highly suggest checking out Cort Johnson’s article One Theory to Explain Them All.