History Of VNS

Many people have epilepsy. Although doctors and scientists have learned a lot about epilepsy over the years and have developed different drugs and other treatments, some people still have seizures. Treatment with the Vagus Nerve stimulator may help reduce the frequency and duration of seizures, where drugs have failed to control them adequately or have caused intolerable side effects.
The Vagus Nerve Stimulator automatically sends a mild electrical stimulation to a nerve that carries information to the brain. This nerve is called the vagus nerve.
Vagus means “wanderer” in Greek. The vagus nerve is well named, considering that on average it is 56centimetres long (22 inches) in adults and wanders through the upper body. The vagus nerve is one of the primary communication lines from the major organs of the body to the brain. The vagus nerve has proven to be a good way to communicate electrically with the brain for several reasons.
· There are few if any pain fibres in the vagus nerve
· Over 80 percent of the electrical signals applied to the vagus nerve in the neck are sent upward to the brain.
· The stimulation electrode is attached to the vagus nerve in a straightforward procedure that does not involve the brain directly and is not brain surgery.

History Of VNS

When was Vagus nerve stimulation first used for the treatment of epilepsy?
Following extensive studies by many researchers that showed changes in brain wave patterns when the Vagus nerve was stimulated, Dr Jacob Zabara applied the technique to prevent seizures or reduce their number, intensity and / or duration.
The first implant in man took place on a patient under the care of Dr. Kiffin Penry in 1988 in the United States of America. Many clinical studies have taken place, the most recent being 196 patients. The results of this extensive study, published in July 1998, authored by 20 eminent physicians in America State:
This trial represents an application of a rigorous drug-study type of design to the assessment of safety and efficacy of a device for epilepsy.

Vagus nerve stimulation is an effective and safe adjunctive (add-on) treatment for patients with refractory partial-onset seizures.
It (Vagus nerve stimulation) represents the advent of a new, non-pharmacological (non-drug) treatment for epilepsy.
This efficacy was demonstrated in a group of epileptic patients with long-standing, highly refractory seizures despite many trials of medication.

To date 700 operations have been carried out in this Country with a lot more world-wide. Statistics show that of those implanted 50% of patients reported a reduction in their number of seizures by 50% or more after twelve to eighteen months of VNS therapy

Benefits of VNS Therapy

Successful VNS Therapy most commonly reduces seizure frequency. Some patients have reported dramatic reductions, others only a slight reduction, and still others no reduction. Overall, however the patients involved in clinical trails for VNS experienced a statistically significant decrease in the frequency of their seizures.
Many patients and Doctors have observed other changes as well. For some patients, VNS has resulted in less severe or shorter seizures, an improved alertness, memory, and cognition, and fewer Casualty Department visits. In addition, some patients have been able to reduce the dosage levels of their anti epileptic medications.
The benefits of VNS Therapy are not always noticeable immediately. In fact, seizure activity may improve gradually over the first two years of treatment. However, long-term results from clinical studies suggest that the effectiveness of VNS Therapy is significant and is maintained over time.

VNS is not a cure for epilepsy, and it does not work for everyone.
Doctors involved in the clinical trials cite the ‘Rule of Thirds’ regarding long-term results, according to these Doctors,
One third of the patients treated with VNS as part of their long term treatment therapy experienced a dramatic improvement in seizure control

One third experienced a good improvement and
One third experienced little or no improvement.
Currently there is no way to predict which patients will respond to VNS Therapy.