What is SCN8A?
SCN8A-related disorders are often manifest in difficult to treat epilepsy that begins in early life and significantly impacts development and quality of life. We are learning that there are many different forms of SCN8A that lead to different kinds of seizure, levels of development and response to medications. There are currently roughly 800 identified cases of SCN8A globally but it is estimated that one in every 60,000 lives births results in an SCN8A mutation.
SCN8A is a gene that plays a critical role in regulating sodium channels in the brain. These sodium channels allow sodium into and out of brain cells called neurons, which generate an electric current called an action potential, allowing neurons to communicate with one another. If there is a gain-of-function mutation in the SCN8A gene, this can cause the sodium channel to malfunction and allow too much sodium into the neurons, which can lead to seizures and the development of epilepsy. Conversely, a loss-of-function mutation in the SCN8A gene can prevent inhibitory neurons from working, which would keep sodium channels for being able to allow in sufficient levels of sodium.
infographics with the latest data SCN8A Registry
a wide spectrum of how those with SCN8A are affected
Everyone with SCN8A has a different treatment story because each case of SCN8A is unique and people can respond to medications in many different ways. Here, we will highlight some of the different types of treatments available to patients.
Anti-seizure medications are primarily used daily in an attempt to reduce the severity and frequency of seizures. Most patients with a gain of function mutation take a sodium channel blocker such as Oxcarbazepine and Carbamazepine, but there are other types of anti-seizure medications that work to stop seizures in different ways.
SCN8A is typically a drug-resistant type of epilepsy that requires trialing many drugs/combinations of drugs to find something that helps reduce seizure frequency and severity. We recommend families work closely with their physicians to find a combination of drugs that reduces seizures and improves quality of life.
Rescue medications are often used to help control extended seizures or clusters of seizures. These medications include Clonazepam, Diazepam, Lorazepam, and Midazolam.
To learn more about rescue medications, please watch this video from our DEE-P Connections project.
When and how to give rescue medications is usually outlined in the seizure action plan.
Every child diagnosed with SCN8A, whether they have had seizures yet or not, should have a seizure action plan. This outlines actions anyone with your child would take in case of a seizure emergency.
To learn more about how to make a seizure action plan, please watch this video from our DEE-P Connections project.
Cannabinoids or CBD can be an alternative treatment for people whose seizures are not controlled by traditional anti-seizure medications, as shown by some lab and small clinical studies. While these studies have been limited so far by federal regulations, the FDA has approved Epidiolex for use in LGS and Dravet Syndrome. Many SCN8A families have tried both Epidiolex and non-FDA-approved cannabinoid-derived treatments (eg Charlotte’s Web).
A recent article from Dr. Jenn Wong studying in SCN8A mouse models showed CBD increased seizure resistance. You can find the article HERE or watch a discussion with her in this recent episode of SCN8A Unraveled.
For more information on CBD in treating rare epilepsies, visit our DEE-P Connections page.
Different types of neurostimulators include deep brain stimulation (DBS), responsive neurostimulation (RNS), and vagus nerve stimulation (VNS). A number of those living with SCN8A have found VNS to be a useful supplementary treatment for seizures.
DBS is when a device is surgically implanted in the brain and sends out programmed electrical pulses in order to interfere with brain signals that cause seizures.
RNS is similar, but instead of the device being programmed by a doctor, a smart device is inserted that acts on its own to monitor brain waves, detect brain signals that could lead to seizures, and disrupt those signals.
VNS is similar to DBS, but the device is implanted under the skin in the area of the heart instead of in the brain.
Source: Epilepsy Foundation
To learn more, please watch our DEE-P Connections webinar on these neurostimulators.
The ketogenic diet is a high fat, low carbohydrate, low protein diet that could reduce seizure frequency. The body usually breaks down carbohydrates into sugar, which it uses as its main source of energy. However, when there are not enough carbohydrates, the body will break down fat into ketones that it can also use for energy. While the exact reason is not known why the keto diet can reduce seizures, these are the main theories:
- Ketones are a more stable energy source for the brain compared to sugars.
- Small chemicals called free radicals cause swelling in the brain and ketones produce less of these than the sugar glucose.
- The presence of ketones leads to a higher production of the chemical GABBA, which works to lower electrical signals in the brain. Lots of electrical signals in the brain are what lead to seizures.
- Acid levels in the blood rise when the body doesn’t have enough carbohydrates. This slightly more acidic environment can keep cell membranes more stable, which could lead to seizure reduction.
Source: Children’s Hospital Colorado
For more information, please visit our DEE-P Connections page.
Anyone who has failed 2 or more anti-seizure medications should receive a brain surgery consultation. Brain surgery can be performed as a way to control seizures by removing the part of the brain where the seizures originate. There are many types of epilepsy surgery outlined by the Epilepsy Foundation. The Brain Recovery Project also has lots of information on when to consider surgery and how to navigate post-surgical life.
New Educational Series
At the International SCN8A Alliance, we believe firmly that every family—no matter their background, education or medical experience—has the right to be able to understand the genetics of SCN8A and what is happening with their child. With this new series, SCN8A Unraveled, we are on a mission to help SCN8A families gain access to and better understand recent research and publications about SCN8A.
This series was made possible with support from Praxis Precision Medicines
Learn More About SCN8A On Our YouTube Channel
To get the basics, watch this introduction to genetics and SCN8A with Dr. Michael Hammer, that shares what we have learned and continue to learn from his dedicated SCN8A registry.
This video, with JP Johnson of Xenon Pharmaceuticals, explains how the channel (mis)functions and how drugs that are in development will hopefully work to correct these errors.