A mutation on the SCN8A gene is a gain-of-function mutation, causing an increase in neuronal excitability. This excessive firing of neurons is what causes our children to experience seizures. Given that the SCN8A gene encodes the sodium channel Nav 1.6, treatment should include medications that are characterized as sodium channel blockers. Keppra, also known as Levetiracetam, does not fall into this category, and as a result, has not proven very successful with our children.
While on Keppra, many children with SCN8A epilepsy experienced an increase in seizure frequency and severity. Once weaned, improvement in many areas was noted, including behavior, alertness, and cognitive functioning. An increase in seizure control was also obtained, once another AED(s) was added at therapeutic levels. Again, medications that fall into the category of sodium channel blockers have been found to be the most effective.
In May 2016, Dr. Michael Hammer reported the results of a survey he conducted on 50 families within the SCN8A support group. Dr. Hammer reported that Keppra usage resulted in a 90% failure rate, with no improvement noted, or with seizures becoming worse. It is also important to note that within the support group, more than 80% of the children have been weaned from Keppra due to its ineffectiveness.
It has been found that those medications which do in fact work for our children, have to be prescribed at very high dosages. Keppra is typically an AED that causes less cognitive slowing when compared to other seizure medications (i.e., Phenobarbital, Depakote), which is why it is often prescribed as a first attempt at seizure control; however, if seizures are worsened because of Keppra, then it can still be indirectly correlated to cognitive dysfunction.
In December 2015, one of the family members within the SCN8A support group posted information regarding an FDA approved and NIH funded drug trial for the treatment of Status Epilepticus in emergency rooms. For this study, Keppra, along with two other emergency medications, would be given on a randomized basis and in very high doses. One of the important features of this trial is that the standard requirement for receiving informed consent before inclusion has been waived by the FDA and NIH. Every patient coming to one of the participating facilities who is eligible for the study would be considered for randomized treatment using one of the three medications being tested. If you are concerned about your child receiving Keppra in this clinical trial, the best action may be to talk to your child’s doctor about adding a contraindication for Keppra/Levetiracetam to your child’s medical record.
In summary, not only has Keppra been found to be highly ineffective in children with SCN8A epilepsy, but in many instances, has made seizures worse in terms of frequency and severity. Medications which have demonstrated the most effectiveness in those children with this type of epilepsy, include AED’s which fall into the category of sodium channel blockers.