Finally, some decent quality research has been done into the use of cannabis to control epileptic seizures. A paper published in the New England Journal of Medicine shows a reduction in the frequency of convulsive seizures in kids suffering from Dravet syndrome. This was a randomised, double-blind, placebo controlled study, which is the standard requirement for a methodologically robust clinical trail, and involved 120 children and young adults.
Dravet syndrome is a mutation involving the SCN1A gene located on chromosome 2 that causes impaired functioning of sodium channels in the brain (and in muscles). This has catastrophic consequences for ionic exchange in neuronal membranes and results in developmental encephalopathy that is associated with a range of different types of epileptic seizures. Dravet syndrome has a high mortality rate, in part because most standard antiepileptic drugs are sodium channel blockers and as such exacerbate the condition.
Enter cannabidiol (CBD), a compound of cannabis. Over 14 weeks of treatment with CBD, the monthly median frequency of convulsive seizures decreased from 12.4 to 5.9 with CBD use. In the placebo group, seizure frequency only fell from 14.9 to 14.1 per month. Convulsive seizures were abolished in 5% of the CBD group, but in none of the placebo group.
Note that while CBD reduced convulsive seizures, it was not beneficial for non-convulsive seizures. Also, negative side effects were much higher in the CBD group and there were more withdrawals from the trial in the CBD group than in the placebo group.
I would note that the mechanism of action of CBD in Dravet syndrome is not clear to me. I don’t understand if it is directly influencing Na channels (and if so, how) or playing some other role in seizure reduction.
Given the misinterpretation of information in social media that often accompanies anything to do with the benefits of cannabis, it is important to stress that the cannabis did not cure Dravet syndrome. This is a relatively small study and needs to be replicated before it is taken as definitive proof. Also, just because cannabis was beneficial in Dravet syndrome, does not mean that it will be beneficial in other forms of epilepsy–that question requires further research. Still, this is a promising result!
Lastly, for the pot-heads out there, this finding does not mean that cannabis cures cancer (yes, we know it says so on Facebook).