Category Archives: Epilepsy

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

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 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.

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 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.

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 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.

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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.

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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

Exploiting cannabinoid and vanilloid mechanisms for epilepsy treatment.

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“This review focuses on the possible roles of phytocannabinoids, synthetic cannabinoids, endocannabinoids, and “transient receptor potential cation channel, subfamily V, member 1” (TRPV1) channel blockers in epilepsy treatment.

The phytocannabinoids are compounds produced by the herb Cannabis sativa, from which Δ9-tetrahydrocannabinol (Δ9-THC) is the main active compound. The therapeutic applications of Δ9-THC are limited, whereas cannabidiol (CBD), another phytocannabinoid, induces antiepileptic effects in experimental animals and in patients with refractory epilepsies.

Synthetic CB1 agonists induce mixed effects, which hamper their therapeutic applications. A more promising strategy focuses on compounds that increase the brain levels of anandamide, an endocannabinoid produced on-demand to counteract hyperexcitability. Thus, anandamide hydrolysis inhibitors might represent a future class of antiepileptic drugs. Finally, compounds that block the TRPV1 (“vanilloid”) channel, a possible anandamide target in the brain, have also been investigated.

In conclusion, the therapeutic use of phytocannabinoids (CBD) is already in practice, although its mechanisms of action remain unclear. Endocannabinoid and TRPV1 mechanisms warrant further basic studies to support their potential clinical applications.”

https://www.ncbi.nlm.nih.gov/pubmed/31839498

“Cannabidiol is in clinical use for refractory epilepsies.”

https://www.epilepsybehavior.com/article/S1525-5050(19)30373-7/fulltext

Cannabinoids and the expanded endocannabinoid system in neurological disorders.

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 Related image“Anecdotal evidence that cannabis preparations have medical benefits together with the discovery of the psychotropic plant cannabinoid Δ9-tetrahydrocannabinol (THC) initiated efforts to develop cannabinoid-based therapeutics.

These efforts have been marked by disappointment, especially in relation to the unwanted central effects that result from activation of cannabinoid receptor 1 (CB1), which have limited the therapeutic use of drugs that activate or inactivate this receptor.

The discovery of CB2 and of endogenous cannabinoid receptor ligands (endocannabinoids) raised new possibilities for safe targeting of this endocannabinoid system. However, clinical success has been limited, complicated by the discovery of an expanded endocannabinoid system – known as the endocannabinoidome – that includes several mediators that are biochemically related to the endocannabinoids, and their receptors and metabolic enzymes.

The approvals of nabiximols, a mixture of THC and the non-psychotropic cannabinoid cannabidiol, for the treatment of spasticity and neuropathic pain in multiple sclerosis, and of purified botanical cannabidiol for the treatment of otherwise untreatable forms of paediatric epilepsy, have brought the therapeutic use of cannabinoids and endocannabinoids in neurological diseases into the limelight.

In this Review, we provide an overview of the endocannabinoid system and the endocannabinoidome before discussing their involvement in and clinical relevance to a variety of neurological disorders, including Parkinson disease, Alzheimer disease, Huntington disease, multiple sclerosis, amyotrophic lateral sclerosis, traumatic brain injury, stroke, epilepsy and glioblastoma.”

https://www.ncbi.nlm.nih.gov/pubmed/31831863

“The existence of the endocannabinoidome explains in part why some non-euphoric cannabinoids, which affect several endocannabinoidome proteins, are useful for the treatment of neurological disorders, such as multiple sclerosis and epilepsy.”

https://www.nature.com/articles/s41582-019-0284-z

The Interplay between the Endocannabinoid System, Epilepsy and Cannabinoids.

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ijms-logo“Epilepsy is a neurological disorder that affects approximately 50 million people worldwide.

There is currently no definitive epilepsy cure. However, in recent years, medicinal cannabis has been successfully trialed as an effective treatment for managing epileptic symptoms, but whose mechanisms of action are largely unknown.

Lately, there has been a focus on neuroinflammation as an important factor in the pathology of many epileptic disorders. In this literature review, we consider the links that have been identified between epilepsy, neuroinflammation, the endocannabinoid system (ECS), and how cannabinoids may be potent alternatives to more conventional pharmacological therapies.

We review the research that demonstrates how the ECS can contribute to neuroinflammation, and could therefore be modulated by cannabinoids to potentially reduce the incidence and severity of seizures. In particular, the cannabinoid cannabidiol has been reported to have anti-convulsant and anti-inflammatory properties, and it shows promise for epilepsy treatment.

There are a multitude of signaling pathways that involve endocannabinoids, eicosanoids, and associated receptors by which cannabinoids could potentially exert their therapeutic effects. Further research is needed to better characterize these pathways, and consequently improve the application and regulation of medicinal cannabis.”

https://www.ncbi.nlm.nih.gov/pubmed/31810321

https://www.mdpi.com/1422-0067/20/23/6079

The use of medical grade cannabis in Italy for drug-resistant epilepsy: a case series.

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 “In Italy, medical grade cannabis (MGC) can be prescribed for different medical conditions, including drug-resistant epilepsy (DRE), once standard and approved therapies have failed, or caused non-tolerable side effects.

Here, we present a retrospective case series report of five patients with DRE who started therapy with MGC. Authorized ISO 9001:2008 pharmacies prepared MGC according to Italian laws. Olive oil extracts (OOEs) were prepared following standard extraction protocols, and cannabinoids were measured on each OOE to check for successful extraction.

After treatment with MGC, all patients reported a reduction in seizure frequency and severity, and some reported improved mood, sleep quality, and general well-being without relevant side effects.

Despite the small sample size and open-label nature of the data, we show that MGC may be successfully used to treat DRE. This is especially true when considering that no valid therapeutic option exists for these patients and that MGC was extremely well tolerated.”

https://www.ncbi.nlm.nih.gov/pubmed/31776867

https://link.springer.com/article/10.1007%2Fs10072-019-04162-1

Cannabinoids for drug-resistant seizures in a critically ill patient-Case report and literature review.

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Publication cover image“Drug-resistant seizures are life-threatening and contribute to sustained hospitalization.

We present the case of a critically ill 28-year-old male with Lennox-Gastaut syndrome who had approximately 30 seizures/day in the intensive care unit.

CASE DESCRIPTION:

Patient required mechanical ventilation and pharmacologically induced thiopentone coma.

He was commenced on cannabidiol and subsequently extubated.

He remained seizure-free thereafter on a combination of cannabidiol and anti-epileptic medication that predated his critical illness.

WHAT IS NEW AND CONCLUSION:

Our case report provides a unique perspective on the role of cannabidiol in achieving remission from drug-resistant seizures in critically ill patients.”

https://www.ncbi.nlm.nih.gov/pubmed/31770462

https://onlinelibrary.wiley.com/doi/abs/10.1111/jcpt.13082