Cannabis in epilepsy: From clinical practice to basic research focusing on the possible role of cannabidivarin.

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“Cannabidivarin (CBDV) and cannabidiol (CBD) have recently emerged among cannabinoids for their potential antiepileptic properties, as shown in several animal models.

We report the case of a patient affected by symptomatic partial epilepsy who used cannabis as self-medication after the failure of countless pharmacological/surgical treatments.

After cannabis administration, a dramatic clinical improvement, in terms of both decrease in seizure frequency and recovery of cognitive functions, was observed, which might parallel high CBDV plasma concentrations.

Our patient’s electroclinical improvement supports the hypothesis that cannabis could actually represent an effective, well-tolerated antiepileptic drug.

Moreover, the experimental data suggest that CBDV may greatly contribute to cannabis anticonvulsant effect through its possible GABAergic action.”

https://www.ncbi.nlm.nih.gov/pubmed/29588939

https://onlinelibrary.wiley.com/doi/abs/10.1002/epi4.12015

Cannabidiol exerts antiepileptic effects by restoring hippocampal interneuron functions in a temporal lobe epilepsy model.

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“A non-psychoactive phytocannabinoid, cannabidiol (CBD), shows promising results as an effective potential antiepileptic drug in some forms of refractory epilepsy.

In an attempt to understand the mechanisms by which CBD exerts its anti-seizure effects, we investigated the effects of CBD at synaptic connections, and the intrinsic membrane properties of hippocampal CA1 pyramidal cells and two major inhibitory interneurons: fast spiking, parvalbumin -expressing (PV) and adapting, cholecystokinin-expressing (CCK) interneurons.

CONCLUSIONS & IMPLICATIONS:

In conclusion, our data suggest CBD restores excitability and morphological impairment in epileptic models to pre-epilepsy control levels through multiple mechanisms to restore normal network function.”

https://www.ncbi.nlm.nih.gov/pubmed/29574880

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14202

Pharmacological characterization of the cannabinoid receptor 2 agonist, β-caryophyllene on seizure models in mice.

Seizure - European Journal of Epilepsy Home

“Activation of CB1 receptors, produces anticonvulsant effect accompanied by memory disturbance both in animal seizure tests and in patients with epilepsy.

Few reports considered the role of CB2 receptor on seizure susceptibility and cognitive functions. The aim of the present study was to explore the effect of a selective CB2 receptor agonist β-caryophyllene (BCP) in models of seizures and cognition in mice.

CONCLUSION:

Our results suggest that the CB2 receptor agonists might be clinically useful as an adjunct treatment against seizure spread and status epilepticus and concomitant oxidative stress, neurotoxicity and cognitive impairments.”

https://www.ncbi.nlm.nih.gov/pubmed/29547827

http://www.seizure-journal.com/article/S1059-1311(17)30611-8/fulltext

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”  http://www.ncbi.nlm.nih.gov/pubmed/23138934

Randomized, dose-ranging safety trial of cannabidiol in Dravet syndrome.

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“To evaluate the safety and preliminary pharmacokinetics of a pharmaceutical formulation of purified cannabidiol (CBD) in children with Dravet syndrome.

Exposure to CBD and its metabolites increased proportionally with dose. An interaction with N-CLB was observed, likely related to CBD inhibition of cytochrome P450 subtype 2C19. CBD resulted in more AEs than placebo but was generally well-tolerated.

CLASSIFICATION OF EVIDENCE:

This study provides Class I evidence that for children with Dravet syndrome, CBD resulted in more AEs than placebo but was generally well-tolerated.”

https://www.ncbi.nlm.nih.gov/pubmed/29540584

http://n.neurology.org/content/early/2018/03/14/WNL.0000000000005254

Anticonvulsive effects of endocannabinoids; an investigation to determine the role of regulatory components of endocannabinoid metabolism in the Pentylenetetrazol induced tonic- clonic seizures.

Metabolic Brain Disease

“2-Arachidonoylglycerol (2-AG) and anandamide are two major endocannabinoids produced, released and eliminated by metabolic pathways.

Anticonvulsive effect of 2-AG and CB1 receptor is well-established. Herein, we designed to investigate the anticonvulsive influence of key components of the 2-AG and anandamide metabolism.

It seems extracellular accumulation of 2-AG or anandamide has anticonvulsive effect through the CB1 receptor, while intracellular anandamide accumulation is proconvulsive through TRPV1.”

https://www.ncbi.nlm.nih.gov/pubmed/29504066

https://link.springer.com/article/10.1007%2Fs11011-018-0195-5

Alterations of endocannabinoids in cerebrospinal fluid of dogs with epileptic seizure disorder.

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“Epilepsy is one of the most common chronic neurological disorders in dogs characterized by recurrent seizures. The endocannabinoid (EC) system plays a central role in suppressing pathologic neuronal excitability and in controlling the spread of activity in an epileptic network. Endocannabinoids are released on demand and their dysregulation has been described in several pathological conditions. Recurrent seizures may lead to an adverse reorganization of the EC system and impairment of its protective effect. In the current study, we tested the hypothesis that cerebrospinal fluid (CSF) concentrations of the endocannabinoids anandamide (AEA) and 2-arachidonoyl glycerol (2AG) are altered in epileptic dogs. Concentrations of AEA and total AG (sum of 2AG and 1AG) were measured in 40 dogs with idiopathic epilepsy and in 16 unaffected, healthy control dogs using liquid chromatography combined with tandem mass spectrometry.

RESULTS:

AEA and total AG were measured at 4.94 (3.18 – 9.17) pM and 1.43 (0.90 – 1.92) nM in epileptic dogs and at 3.19 (2.04 – 4.28) pM and 1.76 (1.08 – 2.69) nM in the control group, respectively (median, 25 – 75% percentiles in brackets). The AEA difference between epileptic and healthy dogs was statistically significant (p < 0.05). Values correlated with seizure severity and duration of seizure activity. Dogs with cluster seizures and/or status epilepticus and with seizure activity for more than six months displayed the highest EC concentrations.

CONCLUSION:

In conclusion, we present the first endocannabinoid measurements in canine CSF and confirm the hypothesis that the EC system is altered in canine idiopathic epilepsy.”

https://www.ncbi.nlm.nih.gov/pubmed/24370333

“In conclusion, we demonstrated an elevation of CSF AEA concentrations in dogs with idiopathic epilepsy. The highest AEA concentrations were found in dogs with severe seizures and a long disease history. Possibly, the activation of the EC system serves as a counter-mechanism in order to regulate the seizure-threshold in epilepsy. However, the EC system can either alter or be altered by seizure activity, so that further, prospective studies are warranted to investigate pathological mechanisms. Despite endocannabinoids can be synthesized “on demand”, the EC system should be considered for development of new treatment strategies against epilepsy.”

https://bmcvetres.biomedcentral.com/articles/10.1186/1746-6148-9-262

Cannabidiol for treatment of refractory childhood epilepsies: Experience from a single tertiary epilepsy center in Slovenia.

“Refractory epilepsies in children present a major burden for patients and their families. Cannabidiol (CBD) has been suggested as a potential treatment for refractory epilepsies. The aim of this study was to evaluate the effectiveness of add-on therapy with CBD for the treatment of refractory childhood epilepsies.

METHOD:

Patients with childhood-onset refractory epilepsy, treated at the tertiary epilepsy center of the University Children’s Hospital Ljubljana, Slovenia, were included in the study. Add-on therapy with CBD was initiated once the child’s epilepsy was categorized as pharmacoresistant to other antiepileptic drugs/therapies. The dosage of CBD was gradually increased to at least 8mg/kg/day. The effect of CBD treatment was evaluated by the reduction in seizure burden and presence of side effects (positive and negative). Serial electroencephalography was performed in some children.

RESULTS:

Sixty-six patients were included in the analysis. Thirty-two (48.5%) patients had a more than 50% improvement regarding seizure burden, 14 of whom (21.2%) became seizure-free. None of the patients reported worsening of seizure frequency, but CBD had no effect in 15 (22.7%) patients. Some patients reported less vigorous seizures, shorter duration of seizures, shorter time to recovery, and other positive side effects of CBD treatment. Adverse effects were reported in 5/66 children.

CONCLUSIONS:

In our cohort of patients, CBD was found to have potential benefits as add-on therapy for refractory childhood epilepsies, mainly by reducing seizure burden.”

https://www.ncbi.nlm.nih.gov/pubmed/29526578

http://www.epilepsybehavior.com/article/S1525-5050(17)30942-3/fulltext

Evidence for cannabis and cannabinoids for epilepsy: a systematic review of controlled and observational evidence.

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“Review evidence for cannabinoids as adjunctive treatments for treatment-resistant epilepsy.

Systematic search of Medline, Embase and PsycINFO was conducted in October 2017. Outcomes were: 50%+ seizure reduction, complete seizure freedom; improved quality of life (QoL).

Tolerability/safety were assessed by study withdrawals, adverse events (AEs) and serious adverse events (SAEs). Analyses were conducted in Stata V.15.0. 36 studies were identified: 6 randomised controlled trials (RCTs), 30 observational studies. Mean age of participants was 16.1 years (range 0.5-55 years).

Cannabidiol (CBD) 20 mg/kg/day was more effective than placebo at reducing seizure frequency by 50%+(relative risk (RR) 1.74, 95% CI 1.24 to 2.43, 2 RCTs, 291 patients, low Grades of Recommendation, Assessment, Development and Evaluation (GRADE) rating). The number needed to treat for one person using CBD to experience 50%+ seizure reduction was 8 (95% CI 6 to 17).

CBD was more effective than placebo at achieving complete seizure freedom (RR 6.17, 95% CI 1.50 to 25.32, 3 RCTs, 306 patients, low GRADE rating), and improving QoL (RR 1.73, 95% CI 1.33 to 2.26), however increased risk of AEs (RR 1.24, 95% CI 1.13 to 1.36) and SAEs (RR 2.55, 95% CI 1.48 to 4.38). Pooled across 17 observational studies, 48.5% (95% CI 39.0% to 58.1%) of patients reported 50%+ reductions in seizures; in 14 observational studies 8.5% (95% CI 3.8% to 14.5%) were seizure-free. Twelve observational studies reported improved QoL (55.8%, 95% CI 40.5 to 70.6); 50.6% (95% CI 31.7 to 69.4) AEs and 2.2% (95% CI 0 to 7.9) SAEs.

Pharmaceutical-grade CBD as adjuvant treatment in paediatric-onset drug-resistant epilepsy may reduce seizure frequency. Existing RCT evidence is mostly in paediatric samples with rare and severe epilepsy syndromes; RCTs examining other syndromes and cannabinoids are needed.”

https://www.ncbi.nlm.nih.gov/pubmed/29511052

http://jnnp.bmj.com/content/early/2018/02/05/jnnp-2017-317168

“Cannabis Compounds Reduce Epileptic Seizure Frequency In Children And Teenagers” http://www.iflscience.com/health-and-medicine/cannabis-compounds-reduce-epileptic-seizure-frequency-in-children-and-teenagers/

“Cannabis ingredient ‘reduces epilepsy seizures'”  https://www.webmd.boots.com/news/20180307/cannabis-ingredient-for-epilepsy-seizures

“Marijuana Derivative Successfully Treats Teen Epilepsy in New Experiments”  https://www.inverse.com/article/41985-cbd-marijuana-treat-seizures-epilepsy

Cannabidiol Regulates Long Term Potentiation Following Status Epilepticus: Mediation by Calcium Stores and Serotonin.

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“Epilepsy is a devastating disease, with cognitive and emotional consequences that are not curable.

In recent years, it became apparent that cannabinoids help patients to cope with epilepsy.

We have studied the effects of cannabidiol (CBD) on the ability to produce long term potentiation (LTP) in stratum radiatum of CA1 region of the mouse hippocampus.

Exposure to seizure-producing pilocarpine reduced the ability to generate LTP in the slice.

Pre-exposure to CBD prevented this effect of pilocarpine.

Furthermore, CBD caused a marked increase in ability to generate LTP, an effect that was blocked by calcium store antagonists as well as by a reduction in serotonin tone. Serotonin, possibly acting at a 5HT1A receptor, or fenfluramine (FFA), which causes release of serotonin from its native terminals, mimicked the effect of CBD.

It is proposed that CBD enhances non-NMDA LTP in the slice by facilitating release of serotonin from terminals, consequently ameliorating the detrimental effects of pilocarpine.”

Cannabis as an anticonvulsant

BMJ Journals“There are records of the cannabis plant being used for medicinal purposes in ancient times, and in the 19th century it was used as an effective anti-epileptic drug (AED) in children.

However, because of its abuse potential, most countries imposed laws restricting its cultivation and use, and this has greatly inhibited research into possible therapeutic uses.

Things are now changing, and cannabis derivatives are now used legally to treat, for example, pain, nausea and spasticity.

The plant contains over 100 biologically active compounds, and recently it has been possible to isolate these and identify the neurochemical mechanisms by which some of them operate: one in particular, cannabidiol”

https://www.ncbi.nlm.nih.gov/pubmed/29449212

http://adc.bmj.com/content/early/2018/02/15/archdischild-2018-314921