Vagus nerve stimulation
Vagus nerve stimulation (VNS) is an invasive medical procedureused to treat clinical depression(including treatment-resistant depression) and epilepsy. It is usually used as a last chance method, when other treatments have failed to work. VNS has only been recently approved by the FDAto treat depression. The FDA has approved VNS for the treatment of depression after at least four pharmacological treatments have failed. VNS has been used to treat epilepsy since 1997.
VNS uses an implant that sends tiny electric shocks to the vagus nerve. The mechanism of action is unknown, but it is this same stimulation - which helps control seizures- that is thought to help depressed patients. It could be thought of as an emotional pacemaker. According to Dr. A. John Rush, vice chairman for research in the Department of Psychiatry at UT Southwestern Medical Center at Dallas, results of the VNS pilot study showed that 40 percent of the treated patients displayed at least a 50 percent or greater improvement in their condition, according to the Hamilton Depression Rating Scale.  The treatment may also have the potential to be used as an alternative to electroconvulsive therapyfor some patients. 
The VNS device is implanted in a patient's chest with wires that connect it to the vagus nerve, which it stimulates to reach a region of the brainassociated with moods. A connecting wire is run under the skin from the device to the vagus nerve in the left side of the neck. Three small leads are then carefully attached to the nerve. Implantation is usually accomplished within 1 to 2 hours. 
FDA medical device chief Dr. Daniel Schultz admitted that the agency was initially skeptical about the device's utility, but pointed out that "these are patients pretty much at the end of the line in terms of what treatment options are available to them."
The VNS device is made by Cyberonics Inc..
| First = Charles E. (III) | Last = Donovan
| Authorlink = Charles E. Donovan III
| Title = Out of the Black Hole: The Patient's Guide to Vagus Nerve Stimulation and Depression
| Publisher = Wellness Publishers, L.L.C
| Location = St. Louis
| Year = 2004
| ID = ISBN 09748-4841-7
- Doctor's Guide: Vagus Nerve Stimulation Successful For Depression
- Neurology Channel: Vagus Nerve Stimulation
- VNS: A New Tool for Brain Research and Therapy (PDF file)
- VagusNerveStimulator.comPublisher's website for Out of the Black Hole
- VNS Message Board- Independent forum where VNS patients share their experiences
Categories: Medical treatment stubs| Surgery| Neurology| Embedded systems
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It uses material from the http://en.wikipedia.org/wiki/Vagus+nerve+stimulation Wikipedia article Vagus nerve stimulation.