In this small preliminary study, 11 people with fibromyalgia had a vagus nerve stimulator implanted for 3 months, and then went back for several follow-up assessments after the implant was removed. (Fourteen people actually began the study; two were unable to tolerate the treatment and dropped out, and one did not come back for follow-up assessment.)
When the 3 months of treatment ended, 5 people showed significant improvement in:
- Overall wellness
- Physical function
Two of those participants also no longer met the fibromyalgia diagnostic criteria of widespread pain and tenderness. Researchers said more participants reached this benchmark by the 11-month follow up, indicating that benefits may continue to grow after treatment has ended.
Side effects of VNS typically include coughing, hoarseness, problems swallowing, and tingling in the neck. In this study, researchers also reported dry mouth and fatigue. However, side effects generally occur only during stimulation and tend to diminish with continued treatment.
Researchers concluded that VNS may be a valuable addition to treatment for some people with fibromyalgia, but they point out that more research is needed to understand its role in the treatment regimen.
It's worth noting that treatment was successful for less than half of the participants 5 or 6 out of 14. Like most treatments, it does not appear to work for all of us.
What is the Vagus Nerve?
While it's generally referred to in the singular, we actually have 2 vagus nerves. They come from either side of the brain stem and run down into the chest and abdomen.
Their job is to help control muscles in the throat and larynx (voice box), regulate the heart rate and digestive system, and send information from the internal organs to the brain.
Dysfunction of the vagus nerve is suspected in both fibromyalgia and chronic fatigue syndrome, especially in cases involving neurally mediated hypotension, which causes dizziness upon standing due to a sudden drop in blood pressure. However, researchers have not yet pinned down the exact role of the nerve in these conditions.
What we do know is that some people are especially susceptible to a problem called "vasovagal reflex." This can be triggered by pain, fear, sudden stress or digestive problems. It causes changes in blood pressure and heart rate that result in dizziness and possibly even loss of consciousness (called vasovagal syncope.)
VNS is sometimes used to treat epilepsy and treatment-resistant depression. Here's information on what the treatment involves, from About.com Depression Guide Nancy Schimelpfening:
Have you been diagnosed with any kind of vagus nerve-related problem? Have you had VNS treatment? Did it help? Leave your comments below!
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