Evidence for the ability of cannabidiol (CBD) to treat various forms of childhood epilepsy has been mounting for some time, yet health authorities remain frustratingly reluctant to prescribe cannabis products to those who need them most. A small number of high-profile cases have caught the attention of the media, leading to a public outcry and forcing the powers that be to grant certain children access to life-saving medications. However, many clinicians continue to argue that cannabis products shouldn’t be used until more is understood about how they work.
To that end, research is currently underway to try and discover exactly how CBD and other cannabinoids prevent seizures in children with epilepsy. The past month has seen the publication of several new studies that significantly advance our understanding of how cannabis produces these effects, strengthening the case for the use of medical marijuana to treat seizures.
CBD Prevents Seizures
A case report that came out this month in the Journal of Neurosciences in Rural Practice describes the incredible recovery of a nine-year-old boy with a severe form of epilepsy called Lennox-Gastaut syndrome. Having previously failed to respond to conventional medications for epilepsy, he became seizure-free thanks to a daily dose of 350 milligrams of CBD[i].
Furthermore, when researchers used electroencephalography to measure the child’s background brain activity patterns, they found that they had stabilised significantly, and began to resemble that of a non-epileptic child.
This study is far from the first to report the astonishing capacity of CBD to eliminate seizures. A 2016 paper in the journal Frontiers in Pharmacology described the recovery of a ten-year-old girl with refractory epilepsy and a seven-year-old boy with a severe form of epilepsy called Dravet syndrome. Both saw massive reductions in seizures shortly after beginning treatment with a cannabis extract containing four percent THC and 90 percent CBD[ii].
However, when the children began to experience side-effects including ataxia and red-eye, doctors switched them both onto a pure CBD extract. Within three weeks, both children were completely free of seizures, and remained so when researchers checked up on them a year later.
How Does CBD Work?
While there is little doubt that CBD is an effective treatment for many kinds of epilepsy, the fact that it interacts with so many different neurotransmitter systems makes it very difficult to pinpoint the exact mechanism underlying its anti-epileptic action.
For example, CBD is known to interact with a receptor called G protein-coupled receptor 55 (GPR55), which has been shown to play a role in Dravet syndrome in mice[iii]. Separate research has indicated that CBD helps to quieten brain activity by binding to opioid receptors[iv], while it has also been hypothesised that the anti-inflammatory properties of CBD can help to treat epilepsy.
Regardless of which receptors are involved, the latest research paints a pretty clear picture about the effect of CBD on brain activity. In addition to the previously-mentioned case study, a separate paper in the latest edition of the journal Epilepsy and Behavior found that CBD completely normalises resting-state functional connectivity (a fancy term for brain activity) in epileptic children[v].
The researchers began by scanning the brains of 22 children with treatment-resistant epilepsy, and found that connectivity patterns varied greatly from healthy controls. In particular, activity in key brain regions like the cerebellum was greatly altered in those who suffered from regular seizures.
According to the study authors, unusual connectivity in the cerebellum is strongly associated with treatment-resistant epilepsy. However, following a three-month course of treatment with CBD, resting-state functional connectivity in the cerebellum and other key brain areas had become completely normal in all of the participants, to the point where it did not differ at all from that of non-epileptic children.
This normalisation of brain activity was accompanied by a significant decrease in seizure frequency and severity. On average, the children involved in the study experienced 72 percent fewer seizures while using CBD. Given that roughly a third of all people with epilepsy don’t respond to current treatments, more research into the efficacy of cannabis to treat this debilitating condition can’t come soon enough.
[i] Prakash V. Effect of Cannabinoids on Electroencephalography of a Child with Lennox–Gastaut Syndrome. Journal of Neurosciences in Rural Practice. 2020 Aug 11. – https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0040-1714329
[ii] Crippa JA, Crippa A, Hallak JE, Martín-Santos R, Zuardi AW. Δ9-THC intoxication by cannabidiol-enriched cannabis extract in two children with refractory epilepsy: full remission after switching to purified cannabidiol. Frontiers in Pharmacology. 2016 Sep 30;7:359. – https://www.frontiersin.org/articles/10.3389/fphar.2016.00359/full
[iii] Senn L, Cannazza G, Biagini G. Receptors and Channels Possibly Mediating the Effects of Phytocannabinoids on Seizures and Epilepsy. Pharmaceuticals. 2020 Aug;13(8):174. – https://www.mdpi.com/1424-8247/13/8/174/htm
[iv] Rodríguez-Muñoz M, Onetti Y, Cortés-Montero E, Garzón J, Sánchez-Blázquez P. Cannabidiol enhances morphine antinociception, diminishes NMDA-mediated seizures and reduces stroke damage via the sigma 1 receptor. Molecular brain. 2018 Dec;11(1):1-2. – https://molecularbrain.biomedcentral.com/articles/10.1186/s13041-018-0395-2
[v] Nenert R, Allendorfer JB, Bebin EM, Gaston TE, Grayson LE, Houston JT, Szaflarski JP. Cannabidiol normalizes resting-state functional connectivity in treatment-resistant epilepsy. Epilepsy & Behavior. 2020 Nov 1;112:107297. – https://www.sciencedirect.com/science/article/abs/pii/S1525505020304765