Category Archives: Epilepsy

Cannabis, More Than the Euphoria: Its Therapeutic Use in Drug-Resistant Epilepsy

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 See the source image“A significant number of epilepsy patients are refractory to conventional antiepileptic drugs. These patients experience considerable neurocognitive impairments that impact their quality of life and ability to function independently. This need for alternative treatment has generated increased interest in cannabis use as a therapeutic option in these patients.

This review seeks to analyze data presented on the pharmacology, safety, and efficacy of cannabis use in patients with drug-resistant epilepsy (DRE) and to propose any future recommendations regarding its use.

The two foremost phytocannabinoids of cannabis showing anticonvulsant properties are tetrahydrocannabinol (THC) and cannabidiol (CBD).

Due to the psychoactive properties of THC, most studies focused on CBD use in these patients. The use of CBD as an adjunct resulted in decreased seizure frequency, and secondary benefits observed included improvement in mood, alertness and sleep. Adverse events (AEs) reported were drowsiness, diarrhea, increased transaminases and worsening of seizures.

It can safely be concluded that there is a significant benefit in DRE patients using CBD as adjunctive therapy. However, further controlled and adequately powered studies are needed to assess the pharmacokinetics and impact of the long-term use of cannabis.”

https://pubmed.ncbi.nlm.nih.gov/32832296/

“The anticonvulsant properties of cannabis have been reported for several years; however, its use as adjunctive therapy in DRE has increased in recent years. Cannabis mediates the ECS, which affects neuronal excitability. This makes it a superior choice for the adjunctive treatment of DRE patients.”

https://www.cureus.com/articles/36299-cannabis-more-than-the-euphoria-its-therapeutic-use-in-drug-resistant-epilepsy

Cannabidiol normalizes resting-state functional connectivity in treatment-resistant epilepsy

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See the source image“Resting-state (rs) network dysfunction is a contributing factor to treatment resistance in epilepsy. In treatment-resistant epilepsy (TRE), pharmacological and nonpharmacological therapies have been shown to improve such dysfunction.

In this study, our goal was to prospectively evaluate the effect of highly purified plant-derived cannabidiol (CBD; Epidiolex®) on rs functional magnetic resonance imaging (fMRI) functional connectivity (rs-FC).

We hypothesized that CBD would change and potentially normalize the rs-FC in TRE.

Results: Participants with TRE showed average decrease of 71.7% in SF (p < 0.0001) and improved CSSS, AEP, and POMS confusion, depression, and fatigue subscores (all p < 0.05) on-CBD with POMS scores becoming similar to those of HCs. Paired t-tests showed significant pre-/on-CBD changes in rs-FC in cerebellum, frontal areas, temporal areas, hippocampus, and amygdala with some of them correlating with improvement in behavioral measures. Significant differences in rs-FC between pre-CBD and HCs were found in cerebellum, frontal, and occipital regions. After controlling for changes in SF with CBD, these differences were no longer present when comparing on-CBD to HCs.

Significance: This study indicates that highly purified CBD modulates and potentially normalizes rs-FC in the epileptic brain. This effect may underlie its efficacy. This study provides Class III evidence for CBD’s normalizing effect on rs-FC in TRE.”

https://pubmed.ncbi.nlm.nih.gov/32745959/

https://www.epilepsybehavior.com/article/S1525-5050(20)30476-5/fulltext

Report of a 6-month-old Asian infant with early infantile epileptic encephalopathy whose seizures were eliminated by cannabidiol

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Epilepsy & Behavior Reports “We observed that cannabidiol supplements were highly effective in treating an infant boy with drug-resistant early infantile epileptic encephalopathy, eliminating his intractable tonic seizures.

The infant began suffering clusters of brief tonic seizures from birth at 39 weeks gestation. EEG showed burst-suppression and seizures could not be controlled by trials of phenobarbital, zonisamide, vitamin B6, clobazam, levetiracetam, topiramate, phenytoin, valproate, high-dose phenobarbital, and ACTH therapy. The boy was discharged from hospital at 130 days of age still averaging tonic seizures 20-30 times per day.

We started him on a cannabidiol supplement on day 207, increasing the dosage to 18 mg/kg/d on day 219. His seizures reduced in frequency and completely disappeared by day 234. These effects were maintained, with improved EEG background, even after his other medications were discontinued.

Cannabidiol’s effectiveness in treating drug-resistant epilepsy has been confirmed in large-scale clinical trials in Europe and the United States; however, no such trials have been run in Asia. In addition, no reports to date have documented its efficacy in an infant as young as six months of age.

This important case suggests that high-dose artisanal cannabidiol may effectively treat drug-resistant epilepsy in patients without access to pharmaceutical-grade CBD.”

https://pubmed.ncbi.nlm.nih.gov/32695984/

“CBD eliminated tonic seizures in a 6-month-old Asian infant with EIEE.  We believe him to be the youngest epilepsy patient treated with CBD in the literature. High-dose artisanal CBD may be helpful in countries without access to Epidiolex.”

https://www.sciencedirect.com/science/article/pii/S2589986420300216?via%3Dihub

Understanding the basics of cannabidiol from cannabis to apply to therapeutics in epilepsy

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Page Header“The compounds present in cannabis have been in use for both recreational and medicinal purposes for many centuries. Changes in the legislation in South Africa have led to an increase in the number of people interested in using these compounds for self-medication. Many of them may approach their general practitioner as the first source of information about possible therapeutic effects. It is important that medical professionals are able to give patients the correct information. Cannabidiol (CBD) is one of the main compounds in cannabis plants, and there is evidence that it can successfully treat certain patients with epilepsy. This review looks at the most recent evidence on the use of CBD in the treatment of epilepsy and explores the mechanisms behind these beneficial effects.”

https://pubmed.ncbi.nlm.nih.gov/32657678/

http://www.samj.org.za/index.php/samj/article/view/12839

Anticonvulsive Properties of Cannabidiol in a Model of Generalized Seizure Are Transient Receptor Potential Vanilloid 1 Dependent

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View details for Cannabis and Cannabinoid Research cover image“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. CBD possesses affinity for many target classes with functional effects relevant to the pathophysiology of many disease types, including epilepsy.

Although the mechanism of action of CBD underlying the reduction of seizures in humans is unknown, transient receptor potential vanilloid 1 (TRPV1) represents a plausible target because (1) CBD activates and then desensitizes TRPV1, (2) TRPV1 is overexpressed in models of temporal lobe epilepsy and patients with epilepsy, (3) and TRPV1 modulates neuronal excitability.

Methods: To investigate a potential role of TRPV1 in the anticonvulsive effects of CBD, the effect of CBD on seizure threshold was assessed using a mouse maximal electroshock threshold model of generalized seizure in TRPV1 knockout and wildtype mice. The dose dependence of the CBD effect was determined and compared with that of the positive comparator diazepam and vehicle.

Results: At 50 and 100 mg/kg, CBD significantly (p<0.0001) increased seizure threshold in wildtype mice compared with TRPV1 knockout and vehicle controls. This effect was observed only at 100 mg/kg in TRPV1 knockout mice compared with knockout vehicle mice, in which gene deletion partially attenuated the CBD-increased seizure threshold. The effect of high-dose CBD in wildtype mice was nevertheless significantly different from vehicle-treated TRPV1 knockout mice (p<0.0001). Bioanalysis confirmed that genotype-specific differential brain exposure to CBD was not responsible for the observed effect on seizure threshold.

Conclusion: These data strongly implicate TRPV1 in the potential mechanisms of action for the anticonvulsive effects of CBD. The partial inhibition of the anticonvulsive effect of high-dose CBD in TRPV1 knockout mice may indicate the involvement of targets other than TRPV1. Further characterization of TRPV1 in the anticonvulsive effect of CBD in validated models of seizure is warranted, as is pharmacological investigation of the molecular interaction between CBD and TRPV1.”

https://pubmed.ncbi.nlm.nih.gov/32656346/

https://www.liebertpub.com/doi/10.1089/can.2019.0028

Interactions Between Cannabidiol and Δ 9 -Tetrahydrocannabinol in Modulating Seizure Susceptibility and Survival in a Mousae Model of Dravet Syndrome

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British Journal of Pharmacology “Extracts from the cannabis plant can dramatically improve the health of children suffering from refractory epilepsies such as Dravet syndrome.

These extracts typically contain cannabidiol (CBD), a phytocannabinoid with well-documented anticonvulsant effects, but may also contain Δ9 -tetrahydrocannabinol (Δ9 -THC). It is unclear whether the presence of Δ9 -THC modulates the anticonvulsant efficacy of CBD. Here we utilized the Scn1a+/- mouse model of Dravet syndrome to examine this question.

Key results: Administered alone, CBD (100 mg/kg i.p.) was anticonvulsant against hyperthermia-induced seizures as were low (0.1 and 0.3 mg/kg i.p.) but not higher doses of Δ9 -THC. A subthreshold dose of CBD (12 mg/kg) enhanced the anticonvulsant effects Δ9 -THC (0.1 mg/kg). Subchronic oral administration of Δ9 -THC or CBD alone did not affect spontaneous seizure frequency or mortality while, surprisingly, their co-administration increased the severity of spontaneous seizures and overall mortality.

Conclusion and implications: Low doses of Δ9 -THC are anticonvulsant against hyperthermia-induced seizures in Scn1a+/ mice, effects that are enhanced by a sub-anticonvulsant dose of CBD. However, proconvulsant effects and increased premature mortality are observed when CBD and Δ9 -THC are subchronically dosed in combination. The possible explanations and implications of this are discussed.”

https://pubmed.ncbi.nlm.nih.gov/32608111/

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.15181

Cannabidiol Efficacy Independent of Clobazam: Meta-Analysis of Four Randomized-Controlled Trials

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 Acta Neurologica Scandinavica“The efficacy of cannabidiol (CBD) with and without concomitant clobazam (CLB) was evaluated in stratified analyses of four large randomized controlled trials, two in Lennox-Gastaut syndrome and two in Dravet syndrome.

Results: The meta-analysis favored CBD vs. placebo regardless of CLB use. The treatment ratio (95% CI) of CBD over placebo for the average reduction in seizure frequency was 0.59 (0.52, 0.68; p<0.0001) with CLB and 0.85 (0.73, 0.98; p=0.0226) without CLB, and the 50% responder rate odds ratio (95% CI) was 2.51 (1.69, 3.71; p<0.0001) with CLB and 2.40 (1.38, 4.16; p=0.0020) without CLB. Adverse events (AEs) related to somnolence, rash, pneumonia, or aggression were more common in patients with concomitant CLB. There was a significant exposure/response relationship for CBD and its active metabolite.

Conclusions: These results indicate CBD is efficacious with and without CLB, but do not exclude the possibility of a synergistic effect associated with the combination of agents. The safety and tolerability profile of CBD without CLB shows a lower rate of certain AEs than with CLB.”

https://pubmed.ncbi.nlm.nih.gov/32592183/

https://onlinelibrary.wiley.com/doi/abs/10.1111/ane.13305

Cannabis Constituents Reduce Seizure Behavior in Chemically-Induced and scn1a-mutant Zebrafish

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Epilepsy and Behavior Journal | Epilepsy Foundation“Current antiepileptic drugs (AEDs) are undesirable for many reasons including the inability to reduce seizures in certain types of epilepsy, such as Dravet syndrome (DS) where in one-third of patients does not respond to current AEDs, and severe adverse effects that are frequently experienced by patients.

Epidiolex, a cannabidiol (CBD)-based drug, was recently approved for treatment of DS. While Epidiolex shows great promise in reducing seizures in patients with DS, it is used in conjunction with other AEDs and can cause liver toxicity. To investigate whether other cannabis-derived compounds could also reduce seizures, the antiepileptic effects of CBD, Δ9-tetrahydrocannabinol (THC), cannabidivarin (CBDV), cannabinol (CBN), and linalool (LN) were compared in both a chemically-induced (pentylenetetrazole, PTZ) and a DS (scn1Lab-/-) seizure models.

Cannabidiol (0.6 and 1 μM) and THC (1 and 4 μM) significantly reduced PTZ-induced total distance moved. At the highest THC concentration, the significant reduction in PTZ-induced behavior was likely the result of sedation as opposed to antiseizure activity.

In the DS model, CBD (0.6 μM), THC (1 μM), CBN (0.6 and 1 μM), and LN (4 μM) significantly reduced total distance traveled. Cannabinol was the most effective at reducing total distance relative to controls. In addition to CBD, other cannabis-derived compounds showed promise in reducing seizure-like activity in zebrafish.

Specifically, four of the five compounds were effective in the DS model, whereas in the PTZ model, only CBD and THC were, suggesting a divergence in the mode of action among the cannabis constituents.”

https://pubmed.ncbi.nlm.nih.gov/32585475/

“In the DS model, CBD, THC, CBN, and LN caused significant reduction in seizure behavior, while THC and CBD were effective in both models.”

https://linkinghub.elsevier.com/retrieve/pii/S1525505020303310

Chronic Cannabidiol Alters Genome-Wide DNA Methylation in Adult Mouse Hippocampus: Epigenetic Implications for Psychiatric Disease

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Environmental and Molecular Mutagenesis“Cannabidiol (CBD) is the primary non-psychoactive compound found in cannabis (Cannabis sativa) and an increasingly popular dietary supplement as a result of widespread availability of CBD-containing products.

CBD is FDA-approved for the treatment of epilepsy and exhibits anxiolytic, antipsychotic, prosocial, and other behavioral effects in animal and human studies, however, the underlying mechanisms governing these phenotypes are still being elucidated. The epigenome, particularly DNA methylation, is responsive to environmental input and can govern persistent patterns of gene regulation affecting phenotype across the life course.

In order to understand the epigenomic activity of chronic cannabidiol exposure in the adult brain, 12-week-old male C57BL/6 mice were exposed to either 20 mg/kg CBD or vehicle daily by oral administration for fourteen days. Hippocampal tissue was collected and reduced-representation bisulfite sequencing (RRBS) was performed. Analyses revealed 3,323 differentially methylated loci (DMLs) in CBD-exposed animals with a small skew toward global hypomethylation.

Genes for cell adhesion and migration, dendritic spine development, and excitatory postsynaptic potential were found to be enriched in a gene ontology term analysis of DML-containing genes, and disease ontology enrichment revealed an overrepresentation of DMLs in gene sets associated with autism spectrum disorder, schizophrenia, and other phenotypes.

These results suggest that the epigenome may be a key substrate for CBD’s behavioral effects and provides a wealth of gene regulatory information for further study.”

https://pubmed.ncbi.nlm.nih.gov/32579259/

https://onlinelibrary.wiley.com/doi/abs/10.1002/em.22396

Cannabidiol Anticonvulsant Effect Is Mediated by the PI3Kγ Pathway

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Neuropharmacology“The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/Akt)/mechanistic target of rapamycin (mTOR) signaling pathway has been associated with several pathologies in the central nervous system (CNS), including epilepsy. There is evidence supporting the hypothesis that the PI3Kγ signaling pathway may mediate the powerful anticonvulsant properties associated with the cannabinoidergic system.

This work aims to investigate if the anticonvulsant and neuroprotective effects of cannabidiol (CBD) are mediated by PI3Kγ.

CDB increased latency and reduced the severity of pilocarpine-induced behavioral seizures, as well as prevented postictal changes, such as neurodegeneration, microgliosis and astrocytosis, in WT animals, but not in PI3Kγ-/-. CBD in vivo effects were abolished by pharmacological inhibition of cannabinoid receptor or mTOR. In vitro, PI3Kγ inhibition or deficiency also changed CBD protection observed in glutamate-induced cell death assay. Thus, we suggest that the modulation of PI3K/mTOR signaling pathway is involved in the anticonvulsant and neuroprotective effects of CBD.

These findings are important not only for the elucidation of the mechanisms of action of CBD, which are currently poorly understood, but also to allow the prediction of therapeutic and side effects, ensuring efficacy and safety in the treatment of patients with epilepsy.”

https://pubmed.ncbi.nlm.nih.gov/32574650/

“CBD is anticonvulsant in a model of pilocarpine-induced behavioral seizures. CB1 receptor mediates the effects of CBD. PI3Kγ pathway mediates the anticonvulsant neuroprotective effects of CBD.”

https://www.sciencedirect.com/science/article/abs/pii/S0028390820302240?via%3Dihub