Category Archives: Epilepsy

Direct Inhibition of BK Channels by Cannabidiol, One of the Principal Therapeutic Cannabinoids Derived from Cannabis sativa

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“Cannabidiol (CBD), one of the main Cannabis sativa bioactive compounds, is utilized in the treatment of major epileptic syndromes. Its efficacy can be attributed to a multimodal mechanism of action that includes, as potential targets, several types of ion channels. In the brain, CBD reduces the firing frequency in rat hippocampal neurons, partly prolonging the duration of action potentials, suggesting a potential blockade of voltage-operated K+ channels. We postulate that this effect might involve the inhibition of the large-conductance voltage- and Ca2+-operated K+ channel (BK channel), which plays a role in the neuronal action potential’s repolarization. Thus, we assessed the impact of CBD on the BK channel activity, heterologously expressed in HEK293 cells. Our findings, using the patch-clamp technique, revealed that CBD inhibits BK channel currents in a concentration-dependent manner with an IC50 of 280 nM. The inhibition is through a direct interaction, reducing both the unitary conductance and voltage-dependent activation of the channel. Additionally, the cannabinoid significantly delays channel activation kinetics, indicating stabilization of the closed state. These effects could explain the changes induced by CBD in action potential shape and duration, and they may contribute to the observed anticonvulsant activity of this cannabinoid.”

https://pubmed.ncbi.nlm.nih.gov/38708937/

“Taken together, our findings expand our understanding of the spectrum of ion channels directly modulated by CBD, suggesting a potential multitarget mechanism underlying its therapeutic effects. Finally, the widespread distribution and function of BK channels in human physiology and pathologies broaden the potential therapeutic uses of CBD to other conditions in which this channel is implicated.”

https://pubs.acs.org/doi/10.1021/acs.jnatprod.3c01274

Cannabidiol attenuates seizure susceptibility and behavioural deficits in adult CDKL5R59X knock-in mice

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“Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is caused by a loss-of-function mutation in CDKL5 gene, encoding a serine-threonine kinase highly expressed in the brain. CDD manifests with early-onset epilepsy, autism, motor impairment and severe intellectual disability.

While there are no known treatments for CDD, the use of cannabidiol has recently been introduced into clinical practice for neurodevelopmental disorders. Given the increased clinical utilization of cannabidiol, we examined its efficacy in the CDKL5R59X knock-in (R59X) mice, a CDD model based on a human mutation that exhibits both lifelong seizure susceptibility and behavioural deficits.

We found that cannabidiol pre-treatment rescued the increased seizure susceptibility in response to the chemoconvulsant pentylenetetrazol (PTZ), attenuated working memory and long-term memory impairments, and rescued social deficits in adult R59X mice. To elucidate a potential mechanism, we compared the developmental hippocampal and cortical expression of common endocannabinoid (eCB) targets in R59X mice and their wild-type littermates, including cannabinoid type 1 receptor (CB1R), transient receptor potential vanilloid type 1 (TRPV1) and 2 (TRPV2), G-coupled protein receptor 55 (GPR55) and adenosine receptor 1 (A1R). Many of these eCB targets were developmentally regulated in both R59X and wild-type mice. In addition, adult R59X mice demonstrated significantly decreased expression of CB1R and TRPV1 in the hippocampus, and TRPV2 in the cortex, while TRPV1 was increased in the cortex.

These findings support the potential for dysregulation of eCB signalling as a plausible mechanism and therapeutic target in CDD, given the efficacy of cannabidiol to attenuate hyperexcitability and behavioural deficits in this disorder.”

https://pubmed.ncbi.nlm.nih.gov/38654472/

“The current report is the first to show experimental evidence that cannabidiol can mitigate some of the memory and social deficits as well as seizure susceptibility in a well-characterized CDD mouse model. These findings continue to support the emerging clinical observational data that cannabidiol-based compounds have efficacy in CDD patients, especially those in later childhood and adulthood.”

https://onlinelibrary.wiley.com/doi/10.1111/ejn.16350

Cannabidiol Exerts Anticonvulsant Effects Alone and in Combination with Δ9-THC through the 5-HT1A Receptor in the Neocortex of Mice

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“Cannabinoids have shown potential in drug-resistant epilepsy treatment; however, we lack knowledge on which cannabinoid(s) to use, dosing, and their pharmacological targets. This study investigated (i) the anticonvulsant effect of Cannabidiol (CBD) alone and (ii) in combination with Delta-9 Tetrahydrocannabinol (Δ9-THC), as well as (iii) the serotonin (5-HT)1A receptor’s role in CBD’s mechanism of action. Seizure activity, induced by 4-aminopyridine, was measured by extracellular field recordings in cortex layer 2/3 of mouse brain slices. The anticonvulsant effect of 10, 30, and 100 µM CBD alone and combined with Δ9-THC was evaluated. To examine CBD’s mechanism of action, slices were pre-treated with a 5-HT1A receptor antagonist before CBD’s effect was evaluated. An amount of ≥30 µM CBD alone exerted significant anticonvulsant effects while 10 µM CBD did not. However, 10 µM CBD combined with low-dose Δ9-THC (20:3 ratio) displayed significantly greater anticonvulsant effects than either phytocannabinoid alone. Furthermore, blocking 5-HT1A receptors before CBD application significantly abolished CBD’s effects. Thus, our results demonstrate the efficacy of low-dose CBD and Δ9-THC combined and that CBD exerts its effects, at least in part, through 5-HT1A receptors. These results could address drug-resistance while providing insight into CBD’s mechanism of action, laying the groundwork for further testing of cannabinoids as anticonvulsants.”

https://pubmed.ncbi.nlm.nih.gov/38534310/

https://www.mdpi.com/2073-4409/13/6/466

The efficacy and safety of cannabidiol (CBD) in pediatric patients with Dravet Syndrome: a narrative review of clinical trials

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“Background: Dravet Syndrome (DS) is a rare and severe form of childhood epilepsy that is often refractory to conventional antiepileptic drugs. Emerging evidence suggests that Cannabidiol (CBD) offer therapeutic benefits for DS. This review aims to evaluate the efficacy and safety of CBD in pediatric patients with DS based on data from ten clinical trials.

Methods: A review was conducted to identify clinical trials assessing the efficacy and safety of CBD in pediatric patients diagnosed with DS. PubMed, MEDLINE, Scopus, Web of Science, and relevant grey literature were systematically searched for relevant articles up to October 2023, and clinical trials within the last 10 years were included. The search strategy incorporated controlled vocabulary terms and keywords related to “Cannabidiol,” “Dravet Syndrome,” and “pediatric patients.”

Results: The analysis revealed promising efficacy outcomes. Notably, CBD demonstrated substantial reductions in seizure frequency, with some patients achieving seizure freedom. The findings emphasised the consistency of CBD’s efficacy across different patient subgroups. The safety profile of CBD was generally acceptable, with adverse events often being manageable.

Conclusion: This review consolidates evidence from multiple clinical trials, affirming the potential of CBD as a promising treatment option for pediatric patients with DS. While further research is needed to address existing knowledge gaps, CBD’s efficacy and acceptable safety profile make it a valuable addition to the therapeutic tools for DS.”

https://pubmed.ncbi.nlm.nih.gov/38500226/

“This review offers a comprehensive and in-depth analysis of the existing evidence on the efficacy and safety of CBD in pediatric patients diagnosed with DS. The findings, compiled from ten distinct clinical trials, consistently point to the potential of CBD as a valuable therapeutic option for managing DS. Notably, CBD remarkably reduces seizure frequency and enhances the overall quality of life for affected patients.”

https://eurjmedres.biomedcentral.com/articles/10.1186/s40001-024-01788-6

Therapeutic applicability of cannabidiol and other phytocannabinoids in epilepsy, multiple sclerosis and Parkinson’s disease and in comorbidity with psychiatric disorders

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“Studies have demonstrated the neuroprotective effect of cannabidiol (CBD) and other Cannabis sativa L. derivatives on diseases of the central nervous system caused by their direct or indirect interaction with endocannabinoid system-related receptors and other molecular targets, such as the 5-HT1A receptor, which is a potential pharmacological target of CBD. Interestingly, CBD binding with the 5-HT1A receptor may be suitable for the treatment of epilepsies, parkinsonian syndromes and amyotrophic lateral sclerosis, in which the 5-HT1A serotonergic receptor plays a key role. The aim of this review was to provide an overview of cannabinoid effects on neurological disorders, such as epilepsy, multiple sclerosis and Parkinson’s diseases, and discuss their possible mechanism of action, highlighting interactions with molecular targets and the potential neuroprotective effects of phytocannabinoids. CBD has been shown to have significant therapeutic effects on epilepsy and Parkinson’s disease, while nabiximols contribute to a reduction in spasticity and are a frequent option for the treatment of multiple sclerosis. Although there are multiple theories on the therapeutic potential of cannabinoids for neurological disorders, substantially greater progress in the search for strong scientific evidence of their pharmacological effectiveness is needed.”

https://pubmed.ncbi.nlm.nih.gov/38477419/

https://onlinelibrary.wiley.com/doi/10.1111/bcpt.13997

Purified cannabidiol as add-on therapy in children with treatment-resistant infantile epileptic spasms syndrome

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“Objective: The aim of this study was to assess efficacy, safety, and tolerability of highly purified cannabidiol oil (CBD) as add-on therapy for the treatment of a series of patients with infantile epileptic spasms syndrome (IESS) who were resistant to antiseizure medications and ketogenic dietary therapy.

Material and methods: We conducted a retrospective analysis of the medical records of 28 infants with treatment-resistant IESS aged 6 to 21 months who received highly purified CBD between July 2021 and June 2023. Data were collected on neurological examinations, EEG, Video-EEG and polygraphic recordings, imaging studies, laboratory testing, and seizure frequency, type, and duration, and adverse effects. As the primary outcome, a reduction of frequency of epileptic spasms (ES) was assessed. ES freedom was considered after a minimal time of 1 month without ES.

Results: Sixteen male and 12 female patients, aged 6-21 months, who received CBD for treatment-resistant IESS were included. The etiology was structural in 10, Down syndrome in seven, genetic in nine, and unknown in two. Initial CBD dose was 2 mg/kg/day, which was uptitrated to a median dose of 25 mg/kg/day (range, 2-50). Prior to CBD initiation, patients had a median of 69 ES in clusters per day (range, 41-75) and of 10 focal seizures per week (range, 7-13). After a mean and median follow-up of 15 and 12.5 months (range, 6-26 months), seven patients were ES free and 12 had a >50 % ES reduction. Five of seven patients (71 %) with Down syndrome and 3/5 (60 %) with cerebral palsy responded well. Adverse effects were mild. EEG improvements correlated with ES reductions.

Conclusion: In this study evaluating the use of CBD in children with IESS, 19/28 (67.8 %) had a more than 50 % ES reduction with good tolerability.”

https://pubmed.ncbi.nlm.nih.gov/38237316/

https://www.seizure-journal.com/article/S1059-1311(24)00018-9/fulltext

Caregiver-reported outcomes with real-world use of cannabidiol in Lennox-Gastaut syndrome and Dravet syndrome from the BECOME survey

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“Purpose: Plant-derived highly purified cannabidiol (CBD) reduced the frequency of seizures associated with Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) and improved the overall condition of patients in placebo-controlled phase 3 clinical trials. Anecdotal reports also suggest a positive effect on nonseizure outcomes. In this study, we aimed to identify, through a caregiver survey which nonseizure outcomes were most likely to change in these patients.

Methods: The BEhavior, COgnition, and More with Epidiolex® (BECOME) was a 20-minute, cross-sectional, online survey that was developed with extensive input from caregivers, healthcare professionals, and epilepsy researchers, and was based on questions from validated measures and previously published caregiver reports. US-based caregivers (from Jazz Pharmaceuticals patient/caregiver database) of people with LGS or DS who were treated with CBD (Epidiolex®, 100 mg/mL oral solution) for ≥3 months were asked to compare the past month to the period before CBD initiation and rate their impression of changes using symmetrical Likert scales

Results: A total of 498 caregivers (97% parents) of patients with LGS (80%) or DS (20%) completed the survey. Mean (range) age of patients was 16 (1-73) years, and 52% were male. Patients were taking a median CBD dose of 14 mg/kg/d and median 4 concomitant antiseizure medications. A large proportion of respondents reported improvements in ≥1 survey question for all nonseizure-related domains: alertness, cognition, and executive function (85%); emotional functioning (82%); language and communication (79% in nonverbal patients and 74% in verbal); activities of daily living (51%); sleep (51%); and physical functioning (46%). Respondents reported improvements in seizure-related domains, including overall seizure frequency (85%), overall seizure severity (76%), seizure-free days per week for ≥1 seizure type (67%), and seizure freedom during the past month (16%). The majority of respondents who reported reduction in seizure frequency also reported improvements in nonseizure outcomes domains (51-80%). However, improvements in nonseizure outcomes (18-56%) were also reported in patients who either had no change or worsening of seizure frequency.

Conclusions: This survey characterized and quantified caregiver impression of changes in the seizure and nonseizure outcomes in patients taking add-on CBD treatment. Overall, 93% of caregivers reported planning to continue CBD treatment, primarily because of reduced seizure burden but also because of improvements in nonseizure-related outcomes. Despite the limitations that are associated with a retrospective survey-based study design, these results support further evaluation of the effect of CBD treatment on nonseizure outcomes among patients with LGS or DS.”

https://pubmed.ncbi.nlm.nih.gov/38183688/

https://www.sciencedirect.com/science/article/pii/S092012112300205X?via%3Dihub

Real-Life Experience With Purified Cannabidiol Treatment for Refractory Epilepsy: A Multicenter Retrospective Study

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“Background: Drug-resistant epilepsy (DRE) affects the development and quality of life of children and young adults. We analyzed the effectiveness and safety of purified CBD in this population.

Methods: A retrospective analysis of medical records of 139 children and young adults (54.7% female, median age 12.0 years) with DRE treated with purified CBD from 2018 to 2022 at five medical centers in Israel.

Results: The most common diagnosis was Lennox-Gastaut syndrome (37.4%) followed by Dravet syndrome (16.5%) and tuberous sclerosis complex (16.5%). Median purified CBD dose was 12.5 mg/kg (range 2.5 to 20.0), and median treatment duration was 9.0 months (range 0.5 to 48.0). Most patients (92.2%) had a reduced seizure frequency following treatment initiation; 41.1% had >50% reduction. Fifty-three patients (38.1%) had positive effects: improved alertness (31.7%), improved speech (10.1%), and achievement of new developmental milestones (2.2%). A multivariate linear model assessing predictive factors for seizure reduction demonstrated that patients previously treated with CBD oils, especially those with >50% seizure reduction on prior treatment, were also more likely to have a reduced seizure frequency while they were treated with purified CBD (P = 0.01, P < 0.0001). Development, diagnosis, age, purified CBD dose (0 to 10 mg/kg/day vs 10 to 20 mg/kg/day), and concomitant treatment with clobazam, valproic acid, or everolimus did not affect seizure reduction by purified CBD. The most common adverse events were irritability (20.9%) and drowsiness (12.9%).

Conclusion: Purified CBD is well-tolerated and effective in reducing seizure frequency in children and young adults with DRE.”

https://pubmed.ncbi.nlm.nih.gov/37995414/

https://www.pedneur.com/article/S0887-8994(23)00362-4/fulltext

Cannabidiol Anticonvulsant Effects Against Lithium-Pilocarpine-Induced Status Epilepticus in Male Rats Are Mediated by Neuroinflammation Modulation and Cannabinoids 1 (CB1), But Not CB2 and GABAA Receptors

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“Background: Status epilepticus (SE) is a series of seizures that can lead to serious neurological damages. Cannabidiol (CBD) is extracted from the cannabis plant, which has been approved as an antiseizure medication. This study aimed to determine the efficacy of various doses of CBD on lithium-pilocarpine-induced SE in rats and possible involvement of multiple pharmacological pathways. We hypothesized that cannabinoid receptors type 1 (CB1) and CB2, as well as GABAA receptors, might have important roles in the anticonvulsant effects of CBD against SE by its anti-inflammatory effects. 

Methods: SE was induced by intraperitoneal (i.p.) injection of lithium (127 mg/kg, i.p.) and pilocarpine (60 mg/kg, i.p., 20 h after lithium). Forty-two male rats were divided into seven groups (including control and sham groups), and the treated groups received different doses of CBD (1, 3, 5, 10, and 25 mg/kg, i.p.). SE score was recorded over the next 2 h following pilocarpine injection. Then, we measured the levels of pro-inflammatory cytokines, including interleukin (IL)-lβ and tumor necrosis factor (TNF)-α, using ELISA kits. Also we analyzed the expression of CB1, CB2, and GABAA receptors using the Western blot technique. 

Results: CBD at 5 mg/kg significantly reduced Racine’s scale and duration of seizures, and increased the onset time of seizure. Moreover, CBD 5 mg/kg caused significant reductions in the elevated levels of IL-lβ and TNF-α, as well as a significant increase in the decreased level of CB1 receptor expression compared to the control group. In other word, CBD reverted the effects of SE in terms of neuroinflammation and CB1 receptor. Based on the obtained results, CBD was not able to restore the declined levels of CB2 or GABAA receptors. 

Conclusion: Our study found anticonvulsant effects of CBD on the SE rat model induced by lithium-pilocarpine with probable involvement of CB1 receptors and anti-inflammatory effects by reducing IL-1β and TNF-α markers independent of CB2 and GABAA receptors.”

https://pubmed.ncbi.nlm.nih.gov/37976207/

https://www.liebertpub.com/doi/10.1089/can.2023.0067

Cannabinoid treatments in epilepsy and seizure disorders

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“Cannabis was used to treat convulsions and other disorders since ancient times. In the last few decades, preclinical animal studies and clinical investigations have established the role of cannabidiol (CBD) in treating epilepsy and seizures and support potential therapeutic benefits for cannabinoids in other neurological and psychiatric disorders. Here, we comprehensively review the role of cannabinoids in epilepsy. We briefly review the diverse physiological processes mediating the central nervous system response to cannabinoids, including D9-THC, cannabidiol, and terpenes. Next, we characterize the anti- and proconvulsive effects of cannabinoids from animal studies of acute seizures and chronic epileptogenesis. We then review the clinical literature on using cannabinoids to treat epilepsy, including anecdotal evidence and case studies as well as the more recent randomized-controlled clinical trials that led to FDA approval of CBD for some types of epilepsy. Overall, we seek to evaluate our current understanding of cannabinoids in epilepsy and focus future research on unanswered questions.”

https://pubmed.ncbi.nlm.nih.gov/37882730/

https://journals.physiology.org/doi/abs/10.1152/physrev.00049.2021