Vagus Nerve Stimulation for Epilepsy Management
Vagus Nerve stimulation is used to treat epilepsy using a stimulator. The stimulator involves a pulse generator that is connected to the left vagus nerve in the neck. Mild and regular electrical stimulations are sent through the nerve which helps in managing the irregular electrical activities in the brain that cause seizures. The vagus nerve stimulation therapy is not controlled with medications.
Vagus nerve stimulation may prevent or lessen seizures by sending regular, mild pulses of electrical energy to the brain via the vagus nerve. The therapy consists of a device that is implanted under the skin in the left chest. An electrode or a wire is attached to the generator device and placed under the skin. The wire is attached or wound around the vagus nerve in the neck. The device is programmed to deliver pulses or stimulations at regular intervals.
Vagus nerve stimulation (VNS) is a type of neuromodulation. It is designed to alter the brain cell function by sending electrical stimulation to certain areas involved in the seizures. The vagus nerve is part of the autonomic nervous system.
VNS helps control seizures by
- Increasing blood flow to key parts of the brain
- Raising the levels of some of the neurotransmitters
- Changing EEG patterns during a seizure
VNS is especially helpful for those patients who are not aware of the occurrence of seizures or if seizures occur at night.
The stimulator is much like a pacemaker. It is connected to the vagus nerve in the side of the neck. The electrodes are coiled around the neck and only a small scar would be left where it was inserted.
The stimulator would be switched on within four weeks of implantation. The neurologist would program the length and strength of the stimulation. The amount of stimulation varies but it is usually adjusted according to the requirements of the patient. Every 5 minutes there would be 30 seconds stimulation. The stimulator runs on a battery which can last for about 10 years.
Patients are provided with a special magnet which they can run over the stimulator to avoid the warning to transform into a full seizure. The magnet is generally worn by the patient around their wrist.
The most common side effect that is reported in this therapy is hoarseness or a change in the patient’s voice.
Other common side effects include
- Sore throat
- Shortness of breath
- Prickling feeling in the skin
- Coughing
- Palpitations
- Difficulty swallowing
- Stomach discomfort
The side effects of the VNS are usually during the stimulation periods. They might improve over time. It is also possible to switch off the stimulator for a short period of time using the magnet. The device can be removed altogether if the discomfort is too much to handle.
A few criteria that are looked at before recommending this therapy are
- Types of seizure that the patient presents with
- Truly drug resistant and uncontrolled epilepsy
- Other health issues that could affect VNS
- Emotional and physical support system