Category Archives: Dravet Syndome

Cannabis for paediatric epilepsy: challenges and conundrums.

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“Research is expanding for the use of cannabidiol as an anticonvulsant drug. The mechanism of cannabidiol in paediatric epilepsy is unclear but is thought to play a role in modulation of synaptic transmission. Evidence for its efficacy in treating epilepsy is limited but growing, with a single pharmaceutical company-funded randomised double-blind controlled trial in children with Dravet syndrome. Progress towards the use of medicinal cannabinoids incorporates a complex interplay of social influences and political and legal reform. Access to unregistered but available cannabidiol in Australia outside of clinical trials and compassionate access schemes is state dependent and will require Therapeutic Goods Administration approval, although the cost may be prohibitive. Further clinical trials are needed to clearly define efficacy and safety, particularly long term.”

https://www.ncbi.nlm.nih.gov/pubmed/29438649

Efficacy of artisanal preparations of cannabidiol for the treatment of epilepsy: Practical experiences in a tertiary medical center.

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“Medically refractory epilepsy continues to be a challenge worldwide, and despite an increasing number of medical therapies, approximately 1 in 3 patients continues to have seizures.

Cannabidiol (CBD), one of many constituents of the Cannabis sativa or marijuana plant, has received renewed interest in the treatment of epilepsy. While highly purified CBD awaits Food and Drug Administration (FDA) approval, artisanal formulations of CBD are readily available and are seeing increased use in our patient population.

Although randomized controlled trials of CBD are ongoing and promising, data regarding artisanal formulations of CBD are minimal and largely anecdotal. Here, we report a retrospective study to define the efficacy of artisanal CBD preparations in children with epilepsy.

Given the known interaction between CBD and clobazam, we also conducted a subgroup comparison to determine if clobazam use was related to any beneficial effects of CBD. Additionally, we compared response rates with CBD and with clobazam alone within an overlapping patient cohort. A pediatric cohort with epilepsy of 108 patients was identified through a medical record search for patients using CBD oil.

The addition of CBD resulted in 39% of patients having a >50% reduction in seizures, with 10% becoming seizure-free. The responder rate for clobazam was similar. No patients achieved CBD monotherapy, although the weaning of other antiepileptic drugs (AEDs) became possible in 22% of patients. A comparable proportion had AED additions during CBD therapy. With concomitant use of clobazam, 44% of patients had a 50% reduction in seizures upon addition of CBD compared with 33% in the population not taking clobazam; this difference was not statistically significant. The most common reported side effect of CBD was sedation in less than 4% of patients, all of whom were also taking clobazam.

Increased alertness and improved verbal interactions were reported in 14% of patients in the CBD group and 8% of patients in the CBD and clobazam group. Benefits were more marked in the CBD alone group, in contrast to the CBD and clobazam group, but this difference was not statistically significant.

In summary, these findings support efficacy of artisanal CBD preparations in seizure reduction with few significant side effects. The response to CBD was independent of concurrent clobazam use, although clobazam may contribute to the sedation seen with concurrent CBD use.”

 https://www.ncbi.nlm.nih.gov/pubmed/29429908
“In this retrospective study, we report that artisanal CBD is helpful in the treatment of medically refractory seizures.”
http://www.epilepsybehavior.com/article/S1525-5050(18)30009-X/fulltext

Cannabidiol for drug-resistant seizures in the Dravet syndrome

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Journal of Paediatrics and Child Health

“Dravet syndrome (severe myoclonic epilepsy of infancy) is characterised by difficult-to-control seizures. Media reports and small clinical trials suggest that cannabidiol, a non-toxic extract of cannabis, can reduce seizure frequency. A recent multicentre randomised controlled trial of 120 children aged 2–18 years with Dravet syndrome supports its efficacy.

Over a 14-week period, children taking 20 mg/kg/day of cannabidiol had a 22.8% reduction (95% confidence interval 5.4–41.1) in seizure frequency compared to a 4-week baseline period. Median convulsive frequency fell from 12.4 to 5.9 per month on cannabidiol, while the placebo group had no change from baseline. No attempt was made to measure non-convulsive seizures (e.g. absences). Subjects took a median of three other anti-convulsant drugs during the trial. Adverse effects were common with cannabidiol, particularly somnolence, fatigue, loss of appetite, vomiting and diarrhoea. Eight patients in the cannabidiol group withdrew compared to one in the placebo group.

Nevertheless, 62% of caregivers in the cannabidiol group felt the patient’s overall condition had improved, using a validated global score, compared to 34% in the placebo group (P = 0.02). Unfortunately, the high rate of adverse events may have led to widespread loss of caregiver blinding, and the study is relatively short term. Nevertheless, the reduction in seizures is clinically relevant, and further longer-term randomised controlled trials are clearly warranted. ” https://www.ncbi.nlm.nih.gov/pubmed/29314377  http://onlinelibrary.wiley.com/doi/10.1111/jpc.13803/full

Do Cannabinoids Confer Neuroprotection Against Epilepsy? An Overview.

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“Cannabinoid-based medications provide not only relief for specific symptoms, but also arrest or delay of disease progression in patients with pain, multiple sclerosis, and other conditions. Although they also seem to hold potential as anticonvulsant agents, evidence of their efficacy in epilepsy is supported by several evidences.

The data reviewed herein lend support to the notion that the endocannabinoid signalling system plays a key modulation role in the activities subserved by the hippocampus, which is directly or indirectly affected in epilepsy patients.

The notion is supported by a variety of anatomical, electrophysiological, biochemical and pharmacological findings. These data suggest the need for developing novel treatments using compounds that selectively target individual elements of the endocannabinoid signalling system.” https://www.ncbi.nlm.nih.gov/pubmed/29290836

“The data reviewed herein demonstrate that cannabinoids provide neuroprotection against brain excitability. They seem to induce at least partial restoration of neurotransmitter dysfunction, inducing an anticonvulsant effect that may be the biological substrate of the complex neurochemical effects reported in experimental and clinical studies. A large body of data suggests that cannabinoids can be harnessed as antiepileptic agents. Finally, among patients with the Dravet syndrome, cannabidiol resulted in a greater reduction in convulsive-seizure frequency than placebo and was associated with higher rates of adverse events and it might reduce seizure frequency and might have an adequate safety profile in children and young adults with highly treatment-resistant epilepsy.”
https://benthamopen.com/FULLTEXT/TONEUJ-11-61

Anticonvulsant Effects of Cannabidiol in Dravet Syndrome

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“The Dravet syndrome is a complex childhood epilepsy disorder that is associated with drug-resistant seizures and a high mortality rate. We studied cannabidiol for the treatment of drug-resistant seizures in the Dravet syndrome. Among patients with the Dravet syndrome, cannabidiol resulted in a greater reduction in convulsive-seizure frequency than placebo and was associated with higher rates of adverse events. The importance of this study is that, unlike most other antiseizure medication trials, it assesses a treatment in a specific epilepsy syndrome with a known genetic basis. CBD resulted in a significant decrease of convulsive seizures and seizures of all types in Dravet syndrome, a pharmacoresistant epilepsy known to be associated with high mortality rates.” http://epilepsycurrents.org/doi/10.5698/1535-7597.17.5.281?code=amep-site

Cannabinoids for epilepsy: What do we know and where do we go?

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Epilepsia

“Over the past decade there has been an increasing interest in using cannabinoids to treat a range of epilepsy syndromes following reports of some remarkable responses in individual patients.

The situation is complicated by the fact that these agents do not appear to work via their attachment to endogenous cannabinoid receptors. Their pharmacokinetics are complex, and bioavailability is variable, resulting in difficulty in developing a suitable formulation for oral delivery. Drug interactions also represent another complication in their everyday use.

Nevertheless, recent randomized, placebo-controlled trials with cannabidiol support its efficacy in Dravet and Lennox-Gastaut syndromes.

Further placebo-controlled studies are underway in adults with focal epilepsy using cannabidivarin. The many unanswered questions in the use of cannabinoids to treat epileptic seizures are briefly summarized in the conclusion.”

https://www.ncbi.nlm.nih.gov/pubmed/29214639

http://onlinelibrary.wiley.com/doi/10.1111/epi.13973/abstract 

Cannabidiol as a treatment for epilepsy

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Journal of Neurology

“Despite an increasing number of anti-epileptic drugs (AEDs), the proportion of drug-resistant cases of epilepsy has remained fairly static at around 30% and the search for new and improved AEDs continues.

Cannabis has been used as a medical treatment for epilepsy for thousands of years; it contains many active compounds, the most important being tetrahydrocannabinol, which has psychoactive properties, and cannabidiol, which does not.

Animal models and clinical data to date have suggested that cannabidiol is more useful in treating epilepsy; there is limited evidence that tetrahydrocannabinol has some pro-convulsant effects in animal models. The mechanism by which cannabidiol exerts its anti-convulsant properties is currently unclear.

Conclusion. The evidence is increasing that cannabidiol is an effective treatment option for childhood onset severe treatment-resistant epilepsies with a tolerable side effect and safety profile. Further evidence is needed before cannabidiol can be considered in more common or adult onset epilepsies. Longer-term safety data for cannabidiol, particularly considering its effects on the developing brain, are also required.”

https://link.springer.com/article/10.1007%2Fs00415-017-8663-0

Cannabidiol attenuates seizures and social deficits in a mouse model of Dravet syndrome.

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Current Issue

“Worldwide medicinal use of cannabis is rapidly escalating, despite limited evidence of its efficacy from preclinical and clinical studies. Here we show that cannabidiol (CBD) effectively reduced seizures and autistic-like social deficits in a well-validated mouse genetic model of Dravet syndrome (DS), a severe childhood epilepsy disorder caused by loss-of-function mutations in the brain voltage-gated sodium channel NaV1.1.

The duration and severity of thermally induced seizures and the frequency of spontaneous seizures were substantially decreased. Treatment with lower doses of CBD also improved autistic-like social interaction deficits in DS mice.

Phenotypic rescue was associated with restoration of the excitability of inhibitory interneurons in the hippocampal dentate gyrus, an important area for seizure propagation. Reduced excitability of dentate granule neurons in response to strong depolarizing stimuli was also observed.

The beneficial effects of CBD on inhibitory neurotransmission were mimicked and occluded by an antagonist of GPR55, suggesting that therapeutic effects of CBD are mediated through this lipid-activated G protein-coupled receptor.

Our results provide critical preclinical evidence supporting treatment of epilepsy and autistic-like behaviors linked to DS with CBD. We also introduce antagonism of GPR55 as a potential therapeutic approach by illustrating its beneficial effects in DS mice.

Our study provides essential preclinical evidence needed to build a sound scientific basis for increased medicinal use of CBD.”

https://www.ncbi.nlm.nih.gov/pubmed/28973916

http://www.pnas.org/content/early/2017/09/26/1711351114

Cannabidiol reduced frequency of convulsive seizures in drug resistant Dravet syndrome.

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BMJ Journals

“Study design

Design: Multinational double-blinded placebo-controlled trial. Patients randomised in 1:1 ratio to receive cannabidiol or placebo, in addition to stable antiepileptic treatment regime.

Study question

Setting: Twenty-three centres in Europe and USA.

 Patients: Patients aged 2 years to 18 years with established diagnosis of Dravet syndrome having at least four convulsive seizures during the 28-day baseline period despite regular antiepileptic medication.

Intervention: Adjunctive cannabidiol or placebo oral solution at 20 mg per kilogram of body weight per day.

Primary outcome: Percentage change in median frequency of convulsive seizures per month.

Follow-up period: Outcome measured over a 14-week treatment period in comparison to a 4-week baseline period.

Patient follow-up: One hundred and eight (90%) completed the trial: 85% (52/61) in the cannabidiol group and …”

http://ep.bmj.com/content/early/2017/09/22/archdischild-2017-313700

The FAAH inhibitor URB597 suppresses hippocampal maximal dentate afterdischarges and restores seizure-induced impairment of short and long-term synaptic plasticity.

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“Synthetic cannabinoids and phytocannabinoids have been shown to suppress seizures both in humans and experimental models of epilepsy.

However, they generally have a detrimental effect on memory and memory-related processes. Here we compared the effect of the inhibition of the endocannabinoid (eCB) degradation versus synthetic CB agonist on limbic seizures induced by maximal dentate activation (MDA) acute kindling. Moreover, we investigated the dentate gyrus (DG) granule cell reactivity and synaptic plasticity in naïve and in MDA-kindled anaesthetised rats.

We found that both the fatty acid amide hydrolase (FAAH) inhibitor URB597 and the synthetic cannabinoid agonist WIN55,212-2 displayed AM251-sensitive anti-seizure effects. WIN55,212-2, dose-dependently (0.5-2 mg/kg, i.p.) impaired short-term plasticity (STP) and long-term potentiation (LTP) at perforant path-DG synapses in naïve rats. Strikingly, URB597 (1 mg/kg, i.p.) was devoid of any deleterious effects in normal conditions, while it prevented seizure-induced alterations of both STP and LTP.

Our evidence indicates that boosting the eCB tone rather than general CB1 activation might represent a potential strategy for the development of a new class of drugs for treatment of both seizures and comorbid memory impairments associated with epilepsy.”

https://www.ncbi.nlm.nih.gov/pubmed/28894217

https://www.nature.com/articles/s41598-017-11606-1