VNS - Vagus Nerve Stimulation
VNS or Vagus Nerve Stimulation is a relatively new treatment for depression but has been used very successfully for epilepsy for a number of years. It is also being used in a slightly different procedure for people who suffer with eating disorders.
What Is It?
VNS is a stimulation of the vagus nerve, working in a way that doctors don't completely understand, to alleviate mood, treat epilepsy or assist people with eating disorders. VNS requires a minor surgical procedure to place a small electrical pulse device, similar to a pacemaker, into the chest. The surgeon also makes an incision in the neck to attach wires from the device to the vagus nerve (the tenth cranial nerve). The device, powered by a small long life battery, then stimulates the vagus nerve on a regular or intermittent basis.
How Does It Work?
The VNS device works by stimulating the left vagus nerve that leads to the brain with low level electrical pulses. If the treatment is successful it can lead to an improvement in mood where people suffer from depression, or help prevent epileptic seizures. After the device is implanted into the chest and the wound has healed, the physician turns it on. The physician can adjust the frequency and level of the stimulation, starting at a low level and gradually building up the pulse intensity over successive appointments until the effective treatment level is reached. The pulse stimulation is normally for 30 seconds every five minutes. Once the correct dose is reached, the frequency of pulsing can be controlled by the patient using a magnetic device. Where VNS is used for eating disorders it is important that the stimulation is intermittent, whereas for depression and epilepsy it usually works best if the stimulation is regular. The device can even be turned off altogether if necessary, for example during exercise.
Is It Effective?
If you suffer from treatment-resistant depression and have tried everything else you may be a suitable candidate for VNS. However due to the nature of depression it doesn't work for everyone and research shows that it is only helpful in about half the cases of treatment-resistant depression. It can take some months of treatment before you will know if it works for you. VNS is also effective in about 80% of cases of epilepsy and appears to be useful for people suffering from eating disorders.
Are There Side Effects?
Yes, but not everybody suffers from them and they may be more acceptable than the side effects of certain medications. The main side effects are a tingling sensation when the device is pulse mode, changes in voice tone, throat pain, coughs and problems with breathing during exercise. If the side effects are troubling the dose can be adjusted, but most people adapt or just turn off the machine when they are exercising or giving a lecture.
Is It Expensive?
Yes, relatively. Typical costs are around $15,000 for the device and up to $15,000 for the surgery. The United States Government's Medicare/Medicaid program only covers VNS treatment in certain specific cases, which at present generally doesn't include treatment- resistant depression. Many private insurance health plans however do cover VNS treatments on a case by case basis so check with your HMO to see if you are covered, if you are considering this treatment.