Like lightning storm causing sudden variation in electricity, seizures also cause similar sudden change in electrical activity of nerve cells in brain.
Seizures or disturbances in the electrical activity of brain cells can be controlled by many medications and in many cases, regular medication can be very effective in prevention of epileptic seizures. But for others, medication may not be helpful, even after prescribing higher dosages and combinations. With these the side effects of strong anti-seizure medications may overweight risks upon benefits. So in these type of situations continuing of two different medications for at least two years is considered as refractory or medically intractable epilepsy.
The comprehensive Epilepsy/Functional Neurosurgery program at KIMS Hospitals provide different surgical options to control seizures and improve quality of life.
Three most common surgical options for epilepsy offered at KIMS Hospitals for patients are Resection Brain Surgery, Vagal Nerve Stimulation and Brain Stimulation. Each procedure has its own risks and benefits.
What is Vagal Nerve Stimulation (VNS) and how does it work?
The Vagus nerve is one of 12 pairs of cranial nerves that originate in the brain and travel down through the neck into chest and abdomen.
Vagus Nerve Stimulation (VNS) therapy is a treatment for epilepsy that involves a stimulator similar to pacemaker implanted below left collar bone which is connected to the left vagus nerve in the neck. Every few minutes stimulator sends regular, mild electrical stimulations through this nerve to help calm down the misfiring of electrical brain activity that leads to seizures.
How does Vagus Nerve Stimulation (VNS) help?
Most patients after vagus nerve stimulation, they say for the first time in so many years, I have more concerned about when my next seizure will occur and no more concern about getting a seizure and their quality of life has improved. Overall the patients noticed the time gap between each successive seizure is increased and decrease in seizure length and severity. VNS is safe adjunctive therapy, in 60% of patients and family members had noticed significant improvement in their quality of life. Moreover VNS can also be used for treatment resistant depression.
Can I be considered for Vagal Nerve Stimulation (VNS)?
VNS therapy is usually considered if you have tried a number of AEDs which have not fully controlled your seizures, and if you are not suitable for, or do not want to have, brain surgery
At KIMS Hospitals Patients are being evaluated by the Epileptologist and once you are diagnosed as refractory epilepsy, patients are offered surgical options. Once patients agree for one of the surgical options and choose VNS, they are evaluated by clinical Neuropsychologist, Functional Neurosurgeon and other team members run some specific tests to decide whether you are fit for surgery or not.
How does the Vagal Nerve Stimulation (VNS) implantation procedure done?
On the day of surgery, after the patient receives preoperative antibiotics, procedure is performed by a Neurosurgeon, usually takes about 45-90 minutes with the patient most commonly under general anesthesia.
The procedure requires two small incisions. The first one is made on the upper left side of the chest where the pulse generator is implanted. A second incision is made horizontally on the left side of the lower neck, along a crease of skin. Electrodes are implanted on the vagus nerve by gently winding the electrode spirals around the nerve. This is where the thin, flexible wires that connect the pulse generator to the vagus nerve are inserted. Once the electrodes are implanted and the system tested, some doctors turn on the system at the lowest setting, while most prefer to wait one or two weeks before initiating stimulation therapy.
Are there any risks and complications of Vagal Nerve Stimulation (VNS)?
Individuals with One vagus nerve, heart abnormalities, gastric or duodenal ulcers, fainting disorder, Pre-existing hoarseness are not suitable for VNS. Side effects are most commonly related to stimulation and usually improve over time which include hoarseness, increased coughing, changes in voice, throat pain, muscle movements or twitching related to the stimulation. Of these, hoarseness, coughing, throat tickling and shortness of breath are the most common and are usually temporary. More over VNS does not affect, and is not affected by, anti-epileptic drugs
Dr. MANAS PANIGRAHI
Sr. Consultant Neurosurgeon
KIMS Hospitals, Secunderabad.