Vagus Nerve Stimulation

Vagus Nerve Stimulation (VNS) therapy is an interventional procedure that does not use any medications for treatment. This is recommended for epileptic patients who do not respond to medications. It is also found to be effective for chronic depression which is insensitive to medications. This therapy has many beneficial aspects that will last for a long time. Adults and teenagers of the age 18, whose seizure activity in resistant to drugs, can undergo this therapy. Small and intermittent charges of electrical energy are sent to the brain through this vagus nerve from the neck area all through the day to prevent seizures.

Vagus (Latin, meaning ‘wandering’) nerve is the tenth cranial nerve and is an extraordinary nerve in that it wanders from brain stem all the way to abdomen and supplies motor parasympathetic fibers to all the organs except the adrenal glands. It carries sensory information from ear, tongue, throat and voice box back to the brain.

Vagus Nerve Stimulation (VNS) Therapy

Vagus nerve stimulation excites a particular area of the brain called limbic system. This limbic system is associated with moods, motivation, alertness, appetite and sleep. The stimulation is applied to the left vagus nerve by a electric pulse generator which is surgically embedded beneath the skin in the chest area on the left side. This generator produces pre-determined and low intensity sporadic electrical charges to the left vagus nerve forever. One small opening has to be made in the upper chest area on the left to place electric charge generator and another opening in the left neck area for connecting the thin lead wires from the generator to the vagus nerve in that area.

The electric energy is provided by a battery cell which will be embedded in the left chest area. The thin lead wires (also known as electrodes) are passed through under the skin and are wrapped around the vagus nerve in the neck. The battery pulse generation is set by the operating team to emit electric charge for a few seconds at a set frequency, say every few minutes. The battery generally lasts for up to six months.

Whenever a patient anticipates an imminent seizure, he or she can activate the pulse generator by simply passing a small magnet over the battery area. This procedure will stop a seizure in some patients. The magnet can also be employed to switch off the generator by holding the magnet over generator embedded area. The whole operation takes about an hour to conclude and the patient can be discharged the same day.

VNS Therapy does not interact with current medications and it will not be a cause for the common side effects of antidepressants. Sleep disturbances and any weight gain are only marginal. This therapy may actually help in reducing the doses of antidepressant medications.

Possible Side Effects of VNS Therapy

Possible side effects are hoarseness of voice, throat discomfiture, mild sensation in the neck area, cough, possible sleep disturbances and sleep apnea. As with any surgical interventions, antibiotics and painkillers will be administered. These post-operative care medications may cause drowsiness, constipation, gastric problems, heart burn, nausea, etc.

Some people reported that they experienced extreme pain and numbness down the arm every time the generator pulsed. Any amount of adjustments with the frequency and pulse duration could not solve the problem. No malfunction or lead impedence was found. It was diagnosed as body reaction to the device.

Side effects with improper implant: Patients may experience facial twitches, lose mobility in their neck, and lose maneuverability with facial expressions, may lose sensation on the left side of the neck, and may feel numbness in the left arm.

Side effects with device malfunction: The malfunction may sometimes cause asystole, i.e., it may stop heart function. The seizing of heart may result in patients experiencing a sharp pain in the throat, followed by choking. It may even lead to unconsciousness.

Precautions

Ensure that VNS implant surgery is performed by a very capable surgical team which is very experienced with the same surgical procedure.

Equipment failure may happen even with best products. Ensure that only efficient and well reputed stimulation apparatus is acquired and current users are consulted for advice and guidance.

Patients should not go for VNS if they had undergone any throat-related surgical procedure before. Patients with any throat disorders should avoid VNS treatment.

Patients should not go for any kind of diathermy procedure as it may affect VNS apparatus.