The proposed mechanism of action of CBD in epilepsy.

Image result for Epileptic Disorders journal“Highly purified cannabidiol (CBD) (approved as Epidiolex® in the United States) has demonstrated efficacy with an acceptable safety profile in patients with Lennox-Gastaut or Dravet syndrome in four randomized controlled trials.

While the mechanism of action of CBD underlying the reduction of seizures in humans is unknown, CBD possesses affinity for multiple targets, across a range of target classes, resulting in functional modulation of neuronal excitability, relevant to the pathophysiology of many disease types, including epilepsy.

Here we present the pharmacological data supporting the role of three such targets, namely Transient receptor potential vanilloid-1 (TRPV1), the orphan G protein-coupled receptor-55 (GPR55) and the equilibrative nucleoside transporter 1 (ENT-1).”

Efficacy and Tolerance of Synthetic Cannabidiol for Treatment of Drug Resistant Epilepsy.

Image result for frontiers in neurology“Controlled and open label trials have demonstrated efficacy of cannabidiol for certain epileptic encephalopathies.

However, plant derived cannabidiol products have been used almost exclusively. Efficacy of synthetically derived cannabidiol has not been studied before.

The objective of this study was to evaluate tolerability and efficacy of synthetic cannabidiol in patients with pharmacoresistant epilepsy.

Efficacy and tolerance in our study of synthetic CBD treatment in pharmacoresistant epilepsy is similar to open label studies using plant derived CBD.

Regarding economic and ecological aspects, synthetic cannabidiol might be a reasonable alternative to plant derived cannabidiol.”

https://www.ncbi.nlm.nih.gov/pubmed/31920934

“Over the last decade, the therapeutic use of cannabidiol (CBD) in intractable epilepsies has increased considerably. Its anticonvulsant properties have been shown in several animal models for acute and chronic epilepsy.

Recent randomized, controlled trials have demonstrated that CBD is superior to placebo in seizure reduction in children with Dravet syndrome and patients with Lennox-Gastaut syndrome. In addition, open label studies indicate that cannabidiol has anticonvulsive properties in a broader range of epilepsy syndromes and etiologies.

In summary, the results of this study provide class III evidence of efficacy and safety of synthetic cannabidiol in children and adults with pharmacoresistant epilepsy. Additional studies investigating efficacy and tolerance of synthetic CBD in larger cohorts are needed.”

https://www.frontiersin.org/articles/10.3389/fneur.2019.01313/full

Efficacy of cannabidiol in subjects with refractory epilepsy relative to concomitant use of clobazam.

Epilepsy Research“To evaluate the efficacy of open-label, highly purified cannabidiol (CBD, Epidiolex®) in treating refractory epilepsy relative to the concomitant use of clobazam (CLB) as well as the clinical implications of changes in CLB and norclobazam (nCLB) levels.”

“With or without concomitant CLB, CBD may be effective in reducing seizure frequency.”   https://www.sciencedirect.com/science/article/abs/pii/S0920121119303778?via%3Dihub

“With or without concomitant CLB, CBD can be effective in reducing seizure frequency. “

https://www.ncbi.nlm.nih.gov/pubmed/31923763

The Use of Cannabis as a Treatment for Epilepsy in Adult Patients: Are Side Effects a Limitation of Use?

 Related image“Marijuana is the dried leaves, stems, and flowers of a 1- to 5-m weed originating from Central Asia. The most common varieties are Cannabis sativa and Cannabis indica. It is usually inhaled as smoke but can also be used as a vapor, taken by mouth as a spray, ingested in tea or as butter in baked goods, or in capsule form and used as an oil. Cannabis has been widely used to treat many medical conditions such as multiple sclerosis symptoms, mood disorders, pain, sleep disorders, and seizures among others. Preclinical and clinical studies have been done over the past decade, among them there are few randomized placebo-controlled trials. In the last few years, Cannabis has been proposed as a potential therapy for patients with drug-resistant epilepsy. This review analyzes the best information about the use of cannabis in adult patients, reviewing aspects of efficacy and safety.”

https://www.ncbi.nlm.nih.gov/pubmed/31895185

https://insights.ovid.com/crossref?an=00004691-202001000-00003

A North American History of Cannabis Use in the Treatment of Epilepsy.

 Related image“Cannabis has been used for millennia in religious ceremonies, for recreation and for its medicinal qualities. There are multiple accounts detailing the specific ailments cannabis has been used to treat, many of which have included epilepsy. Racial discrimination and political stigmatization led to prohibition, which limited both patients’ and researchers’ access to the drug through the 20th century. Recently, academic interest has been renewed in cannabis, especially regarding the modulation of cortical excitability via the human endocannabinoid system. Modern research has produced several promising studies regarding the treatment of epileptic encephalopathies. Legalization of marijuana in Canada has potentially allowed for further trials, but it is by no means an end to the controversy surrounding the treatment of epilepsy with cannabinoids.”

https://www.ncbi.nlm.nih.gov/pubmed/31895188

https://insights.ovid.com/crossref?an=00004691-202001000-00006

The Endocannabinoid System and Synthetic Cannabinoids in Preclinical Models of Seizure and Epilepsy.

 Related image“Cannabinoids are compounds that are structurally and/or functionally related to the primary psychoactive constituent of Cannabis sativa, [INCREMENT]-tetrahydrocannabinol (THC). Cannabinoids can be divided into three broad categories: endogenous cannabinoids, plant-derived cannabinoids, and synthetic cannabinoids (SCs).

Recently, there has been an unprecedented surge of interest into the pharmacological and medicinal properties of cannabinoids for the treatment of epilepsies. This surge has been stimulated by an ongoing shift in societal opinions about cannabinoid-based medicines and evidence that cannabidiol, a nonintoxicating plant cannabinoid, has demonstrable anticonvulsant activity in children with treatment-refractory epilepsy.

The major receptors of the endogenous cannabinoid system (ECS)-the type 1 and 2 cannabinoid receptors (CB1R, CB2R)-have critical roles in the modulation of neurotransmitter release and inflammation, respectively; so, it is not surprising therefore that the ECS is being considered as a target for the treatment of epilepsy.

SCs were developed as potential new drug candidates and tool compounds for studying the ECS. Beyond the plant cannabinoids, an extensive research effort is underway to determine whether SCs that directly target CB1R, CB2R, or the enzymes that breakdown endogenous cannabinoids have anticonvulsant effects in preclinical rodent models of epilepsy and seizure.

This research demonstrates that many SCs do reduce seizure severity in rodent models and may have both positive and negative pharmacodynamic and pharmacokinetic interactions with clinically used antiepilepsy drugs. Here, we provide a comprehensive review of the preclinical evidence for and against SC modulation of seizure and discuss the important questions that need to be addressed in future studies.”

https://www.ncbi.nlm.nih.gov/pubmed/31895186

https://insights.ovid.com/crossref?an=00004691-202001000-00004

Cannabis for Pediatric Epilepsy.

 Related image“Epilepsy is a chronic disease characterized by recurrent unprovoked seizures. Up to 30% of children with epilepsy will be refractory to standard anticonvulsant therapy, and those with epileptic encephalopathy can be particularly challenging to treat.

The endocannabinoid system can modulate the physiologic processes underlying epileptogenesis. The anticonvulsant properties of several cannabinoids, namely Δ-tetrahydrocannabinol and cannabidiol (CBD), have been demonstrated in both in vitro and in vivo studies.

Cannabis-based therapies have been used for millennia to treat a variety of diseases including epilepsy. Several studies have shown that CBD, both in isolation as a pharmaceutical-grade preparation or as part of a CBD-enriched cannabis herbal extract, is beneficial in decreasing seizure frequency in children with treatment-resistant epilepsy.

Overall, cannabis herbal extracts appear to provide greater efficacy in decreasing seizure frequency, but the studies assessing cannabis herbal extract are either retrospective or small-scale observational studies. The two large randomized controlled studies assessing the efficacy of pharmaceutical-grade CBD in children with Dravet and Lennox-Gastaut syndromes showed similar efficacy to other anticonvulsants. Lack of data regarding appropriate dosing and pediatric pharmacokinetics continues to make authorization of cannabis-based therapies to children with treatment-resistant epilepsy challenging.”

https://www.ncbi.nlm.nih.gov/pubmed/31895184

https://insights.ovid.com/crossref?an=00004691-202001000-00002

CB2R orchestrates neuronal autophagy through regulation of the mTOR signaling pathway in the hippocampus of developing rats with status epilepticus.

 Journal Cover“Neuronal loss and gliosis are the major pathological changes after status epilepticus (SE).

The authors’ previous study revealed the time‑dependent changes of cannabinoid receptor type 2 (CB2R) in hippocampal neurons of developing rats after SE, which were accompanied by a decrease in the number of neurons. Meanwhile, growing evidence indicates that CB2R stimulation exerts anti‑convulsant properties in seizure models. However, the activation of CB2R in neuronal repair in response to the damage after SE is still unclear.

In this experiment, a highly‑selective CB2R agonist JWH133 and antagonist AM630 were administered to determine the activity of CB2R in neuronal autophagy and apoptosis of the post‑SE repair in developing rats. The present results revealed that activation of CB2R by JWH133, not only obviously lowered the success rate, 24‑h death rate and the Racine stage in the model, but also extended the latency period to SE. In addition, compared with the vehicle control group, CB2R activation increased neuronal autophagy and the expression of phosphorylated‑mammalian target of rapamycin (p‑mTOR)/mTOR, Beclin‑1, and LC3II/LC3I while decreasing the expression of p‑Unc‑51‑like autophagy‑activating kinase 1 (ULK‑1)/ULK1, p62, and cleaved caspase‑3.

These results were dose‑dependent and were especially evident in the high‑dose group, and interestingly the opposite results were obtained in the AM630 group. Thus, CB2R orchestrates neuronal autophagy through regulation of the mTOR signaling pathway in the hippocampus of developing rats with SE. These findings might provide an important basis for further investigation of the therapeutic role of CB2R in ameliorating epilepsy‑related neuronal damage.”

https://www.ncbi.nlm.nih.gov/pubmed/31894322

https://www.spandidos-publications.com/10.3892/ijmm.2019.4439

Cannabis-based products for pediatric epilepsy: An updated systematic review.

Seizure - European Journal of Epilepsy Home“To provide an up-to-date summary of the benefits and harms of cannabis-based products for epilepsy in children.

METHODS:

We updated our earlier systematic review, by searching for studies published up to May 2019. We included randomized controlled trials (RCTs) and non-randomized studies (NRS) involving cannabis-based products administered to children with epilepsy. Outcomes were seizure freedom, seizure frequency, quality of life, sleep, status epilepticus, death, gastrointestinal adverse events, and emergency room visits.

RESULTS:

Thirty-five studies, including four RCTs, have assessed the benefits and harms of cannabis-based products in pediatric epilepsy (12 since April 2018). All involved cannabis-based products as adjunctive treatment, and most involved cannabidiol. In the RCTs, there was no statistically significant difference between cannabidiol and placebo for seizure freedom (relative risk 6.77, 95 % confidence interval [CI] 0.36-128.38), quality of life (mean difference [MD] 0.6, 95 %CI -2.6 to 3.9), or sleep disruption (MD -0.3, 95 %CI -0.8 to 0.2). Data from both RCTs and NRS suggest that cannabidiol reduces seizure frequency and increases treatment response; however, there is an increased risk of gastrointestinal adverse events.

CONCLUSION:

Newly available evidence supports earlier findings that cannabidiol probably reduces the frequency of seizures among children with drug-resistant epilepsy.”

https://www.ncbi.nlm.nih.gov/pubmed/31865133

https://www.seizure-journal.com/article/S1059-1311(19)30733-2/fulltext

Potential role of cannabidiol for seizure control in a patient with recurrent glioma.

Journal of Clinical Neuroscience Home“Glioma-related epilepsy significantly impact on patients’ quality of life, and can often be difficult to treat. Seizures cause significant morbidity for example neurocognitive deterioration, which may result from seizures themselves or due to adverse effects from antiepileptic drugs. Management of tumour with surgery, radiotherapy and chemotherapy may contribute to seizure control, but tumour related epilepsy is often refractory despite adequate treatment with standard anti-epileptic medications. Given the increasing interest in medicinal cannabis (or cannabidiol or CBD) as an anti-epileptic drug, CBD may help with seizure control in glioma patients with treatment-refractory seizures. Here we present a case of a young lady with recurrent glioma who had refractory seizures despite multiple anti-epileptic agents, who had significant benefit with CBD.”

https://www.ncbi.nlm.nih.gov/pubmed/31848037

“CBD could potentially be a management option in treatment-refractory epilepsy in glioma patients.”

https://www.jocn-journal.com/article/S0967-5868(19)31306-2/fulltext