Antiepileptic Drugs (AEDs)
Seizures have many causes from many different reasons (genetic, trauma, stroke etc).
30% of patients don’t respond to AEDs, so some resolve to alternative medications such as nerve stimulation, responsive nerve stimulation, epilepsy surgery etc.
AEDs are designed to treat seizures.
Vagus Nerve Stimulator
The VNS, also known as the “pacemaker for the brain," is a device that is implanted under the skin in the left chest area. 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.
While not everything is understood on how it works, the VNS sends regular, mild pulses of electrical energy to the brain via the vagus nerve which is believed to modify seizure activity.
A review of 65 people who’ve had VNS for 10 years or more, showed improvements in seizure control over time. Seizures decreased by 36% after 6 months, 58% after 4 years, and 75% by 10 years after the VNS was placed.
Other important VNS Facts:
- People with VNS have an average decrease in seizures by 28% in the first 3 months.
- More than 60,000 individuals have implanted VNS devices worldwide.
- The VNS does not interact with medications.
Epilepsy Surgery
Surgery is an alternative for some people whose seizures cannot be controlled by medications More recently, surgery is being considered sooner. Studies have shown that the earlier surgery is performed, the better the outcome.
The benefits of surgery should be weighed carefully against its risks, however, because there is no guarantee that it will be successful in controlling seizures.
Types of epilepsy surgery:
- Resection or resective surgery: The surgeon removes the area of the brain that causes the patient's seizures.
- Temporal lobectomy (removal of part of the temporal lobe) is the most common type of resection surgery.
- Disconnection surgery: Interrupts nerve pathways that allow seizures to spread.
- Multiple subpial transections is a disconnective procedure that may be helpful when seizures begin in areas that are too important to remove such as language areas.
- Generally, this type of surgery is a way of providing relief, not curing seizures.
- Corpus Callosotomy can be performed using a scope and disconnects the right and left hemispheres. It can be used for “atonic” or “tonic” seizures.
- Multiple subpial transections is a disconnective procedure that may be helpful when seizures begin in areas that are too important to remove such as language areas.
Responsive Neurostimulation (RNS)
The Responsive Neurostimulation System (RNS) is a smart device that is adjustable from the computer. Where it is placed and how it is used is specific to each person.
The RNS System can monitor brain waves, then respond to activity that is different from usual or that looks like a seizure by programming the device remotely by the physician. (click to watch video)
Most epilepsy centers that provide epilepsy surgery can also offer the RNS System.
RNS Therapy does not cause any pain or unusual feelings and has shown to reduce seizures and improve quality of life in most people who have used it.
Before having the RNS placed, a person must go through detailed testing to see where their seizures occur in the brain.
So far, 2 out of 3 people with the RNS System (66%) had their seizures cut in half after 7 years of using it.
Two hundred and thirty patients with the RNS System were followed over time in a controlled trial. The average decrease in seizures was 44% after 1 year, 53% at 2 years, and up to 66% after 3 to 6 years of using RNS.
Deep Brain Stimulation
Deep brain stimulation (DBS) has been used for over twenty years in the treatment of other neurological disorders such as Parkinson’s disease. It was approved for the treatment of refractory epilepsy in mid-2018.
DBS involves implanting electrodes deep within the brain through small holes in the skull by a functional neurosurgeon. No areas of brain tissue are removed.
The amount of stimulation delivered by the electrodes is controlled by a pacemaker-like device placed under the skin in the chest. A wire that travels under the skin connects the device to the electrode. The generator is then controlled using a remote held over the chest by a physician and different settings can be used to adjust the settings to achieve optimal seizure control.
*Image copyright Mayo Foundation for Medical Education & Research