Long-term use of cannabidiol-enriched medical cannabis in a prospective cohort of children with drug-resistant developmental and epileptic encephalopathy

Rapid seizure resolution with cannabidiol in medically refractory epilepsy with myoclonic-atonic seizures

Epilepsy with myoclonic-atonic seizures (EMAS) is an early childhood epilepsy syndrome with an explosive onset of multiple seizure types in a previously healthy child. EMAS often evolves to a drug-resistant epileptic encephalopathy before a variable degree of remission around 3 years from onset. Highly purified cannabidiol (CBD, available in United States as Epidiolex®) has demonstrated efficacy and tolerability as an adjunct in medically refractory EMAS. We present two cases of medically refractory EMAS achieving rapid seizure freedom (7-30 days) with CBD, illustrating CBD as a potential effective monotherapy in EMAS.

Cannabinoids and Genetic Epilepsy Models: A Review with Focus on CDKL5 Deficiency Disorder

Pediatric genetic epilepsies, such as CDKL5 Deficiency Disorder (CDD), are severely debilitating, with early-onset seizures occurring more than ten times daily in extreme cases. Existing antiseizure drugs frequently prove ineffective, which significantly impacts child development and diminishes the quality of life for patients and caregivers. The relaxation of cannabis legislation has increased research into potential therapeutic properties of phytocannabinoids such as cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC). CBD's antiseizure properties have shown promise, particularly in treating drug-resistant genetic epilepsies associated with Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS), and Tuberous Sclerosis Complex (TSC). However, specific research on CDD remains limited. Much of the current evidence relies on anecdotal reports of artisanal products lacking accurate data on cannabinoid composition. Utilizing model systems like patient-derived iPSC neurons and brain organoids allows precise dosing and comprehensive exploration of cannabinoids' pharmacodynamics. This review explores the potential of CBD, THC, and other trace cannabinoids in treating CDD and focusing on clinical trials and preclinical models to elucidate the cannabinoid's potential mechanisms of action in disrupted CDD pathways and strengthen the case for further research into their potential as anti-epileptic drugs for CDD. This review offers an updated perspective on cannabinoid's therapeutic potential for CDD.

Use of artisanal and non-regulated cannabis-based products for the treatment of epilepsy in a low-income population

INTRODUCTION

Several artisanal and non-regulated cannabis-based products used for the treatment of epilepsy are available and can be easily obtained. Many of these preparations lack proper quality validation and exhibit cannabinoid contents significantly different from those stated on their labels, along with the presence of potentially harmful compounds. This study aims to evaluate the frequency of use and prescription patterns of these products among patients with epilepsy from a low-income population.

METHODS

Observational and cross-sectional study. A survey was conducted on patients with epilepsy at a public hospital in Bogotá, Colombia.

RESULTS

A total of 380 patients were evaluated, with 10.3 % (n = 39) reporting the use of artisanal and non-regulated cannabis-based products for the treatment of epilepsy. Among these patients, 84.6 % (n = 33) used the product on their own initiative, without a medical recommendation. Only 7.7 % (n = 3) of the patients had a record of the consumption of these products in their medical history. Age (p = 0.002), type of therapeutic response (p = 0.01), number of previous antiseizure medications used (p < 0.01), and non-pharmacological treatment such as vagal nerve stimulation (p < 0.01) showed a statistically significant association with the utilization of these products.

CONCLUSION

One in ten patients with epilepsy has used artisanal and non-regulated cannabis-based products for the treatment of their condition. The majority of patients used these products on their own initiative, without a medical recommendation. The prevalence of consuming these products was higher among younger individuals with uncontrolled epilepsy, who had previously used multiple antiseizure medications and other non-pharmacological alternatives such as vagal nerve stimulation.

Medical cannabis for children: Evidence and recommendations

Interest in using cannabis products for a medical purpose in children under the age of 18 years is increasing. There are many medical cannabis products available that can include cannabidiol (CBD) or delta-9-tetrahydrocannabinol (THC), or both. Despite many therapeutic claims, there are few rigorous studies to inform the dosing, safety, and efficacy of medical cannabis in paediatric clinical practice. This statement reviews the current evidence and provides recommendations for using medical cannabis in children. Longer-term (2-year) reports support the sustained tolerability and efficacy of cannabidiol therapy for patients with Lennox-Gastaut and Dravet syndromes. CBD-enriched cannabis extracts containing small amounts of THC have been evaluated in a small number of paediatric patients, and further research is needed to inform clinical practice guidelines. Given the widespread use of medical cannabis in Canada, paediatricians should be prepared to engage in open, ongoing discussions with families about its potential benefits and risks, and develop individualized plans that monitor efficacy, reduce harms, and mitigate drug-drug interactions.

Les données probantes et les recommandations sur le cannabis à des fins médicales chez les enfants

L'intérêt envers l'utilisation des produits du cannabis à des fins médicales chez les enfants de moins de 18 ans augmente. De nombreux produits du cannabis à des fins médicales contiennent du cannabidiol, du delta-9-tétrahydrocannabinol ou ces deux produits. Malgré les nombreuses prétentions thérapeutiques, peu d'études rigoureuses guident la posologie, l'innocuité et l'efficacité du cannabis à des fins médicales en pédiatrie clinique. Le présent document de principes passe en revue les données probantes à jour et expose les recommandations sur l'utilisation du cannabis à des fins médicales chez les enfants. Les rapports à plus long terme (deux ans) souscrivent à la tolérabilité et à l'efficacité soutenues d'un traitement au cannabidiol chez les patients ayant le syndrome de Lennox-Gastaut ou le syndrome de Dravet. Les extraits de cannabis enrichis de cannabidiol qui renferment de petites quantités de delta-9-tétrahydrocannabinol ont été évalués auprès d'un petit nombre de patients d'âge pédiatrique, et d'autres recherches devront être réalisées pour éclairer les guides de pratique clinique. Étant donné l'utilisation répandue du cannabis à des fins médicales au Canada, les pédiatres devraient être prêts à participer à des échanges ouverts et continus avec les familles au sujet de ses avantages potentiels et de ses risques, ainsi qu'à préparer des plans individuels en vue d'en surveiller l'efficacité, de réduire les méfaits et de limiter les interactions médicamenteuses.

Continuous spike-wave of slow sleep in a patient with KCNB1-related epilepsy responsive to highly purified cannabidiol: a case report and comparison with literature

KCNB1-associated encephalopathy is characterized by intellectual disability (ID), autism spectrum disorder and epilepsy. Specific treatments are still lacking. We describe a 12-year-old boy with severe ID and treatment-resistant seizures due to a pathogenic KCNB1 variant. His EEG showed a CSWS pattern. Aged 11, he started treatment with highly purified cannabidiol (CBD) and has been seizure free for 18 months, with significant EEG and social skills improvements. This suggests CBD may benefit CSWS, likely due to its anti-inflammatory properties. Some preclinical studies also indicate CBDs interact with voltage-gated channels, leading us to speculate its possible role for treating KCNB1 related encephalopathy.

Medicinal plants for epileptic seizures: Phytoconstituents, pharmacology and mechanisms revisited

ETHNOPHARMACOLOGICAL RELEVANCE

Epilepsy is a neurological disorder that presents with recurring and spontaneous seizures. It is prevalent worldwide, affecting up to 65 million people, with 80% of cases found in lower-income countries. Medicinal plants are commonly employed for managing and treating epilepsy and convulsions due to their unique therapeutic properties. With increasing research and clinical application, medicinal plants are gaining attention globally due to their potent therapeutic effects and fewer side effects. The development of new plant-based antiepileptic/anticonvulsant agents has become a major focus in the pharmaceutical industry.

AIM OF THE REVIEW

This article summarizes recent research on medicinal plants with reported antiepileptic/anticonvulsant effects. It provides pharmacological and molecular mechanism of action information for the crude extracts and related active constituents evaluated in preclinical research for the treatment of epilepsy and convulsions, and offers a reference for the development of future related studies in this area.

MATERIALS AND METHODS

Articles related to ethnopharmacological and antiepileptic studies on plants or natural products from 2018 to 2023 were collected from PubMed, Web of Science and Scopus, etc. using keywords related to epilepsy, medicinal plants, and natural products, etc. RESULTS: Eighty plant species are commonly used to treat epilepsy and convulsions in African and Asian countries. Sixty natural products showing potential for antiepileptic/anticonvulsant effects have been identified from these medicinal plants. These products can be broadly classified as alkaloids, coumarins, flavonoids, saponins, terpenoids and other compounds. The antiepileptic action of plant extracts and their active ingredients can be classified according to their abilities to modulate the GABAergic and glutamatergic systems, act as antioxidants, exhibit anti-neuroinflammatory effects, and provide neuroprotection. In addition, we highlight that some medicinal plants capable of pharmacologically relieving epilepsy and cognition may be therapeutically useful in the treatment of refractory epilepsy.

CONCLUSIONS

The review highlights the fact that herbal medicinal products used in traditional medicine are a valuable source of potential candidates for antiepileptic drugs. This confirms and encourages the antiepileptic/anticonvulsant activity of certain medicinal plants, which could serve as inspiration for further development. However, the aspects of structural modification and optimization, metabolism, toxicology, mechanisms, and clinical trials are not fully understood and need to be further explored.

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

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.

Long-term efficacy and adverse effects of cannabidiol in adjuvant treatment of drug-resistant epilepsy: a systematic review and meta-analysis

Background

Epilepsy is one of the most common chronic brain diseases. Almost one-third of patients have drug-resistant epilepsy (DRE). Cannabidiol is being considered as a potential novel drug for treating DRE.

Objectives

To investigate long-term efficacy and safety of cannabidiol in treatment of DRE and the differences in cannabidiol treatment among patients with different characteristics.

Design

Systematic review and meta-analysis.

Data sources and methods

Medline, Embase, and CENTRAL were searched for literature. RevMan5.4 was used for meta-analysis. The Intention-to-treat set and the random effect were used as the main analysis. Subgroup analyses were performed according to age, dose, concomitant antiseizure medications (ASMs), epilepsy syndromes, and study designs.

Results

Fifty studies were included in this systematic review. A total of 4791 participants were collected. The responder rates (seizure frequency reduced at least 50%) at 12-, 24-, 48-, 72-, 96-, and 144-week were 0.40 [0.36, 0.45], 0.39 [0.34, 0.44], 0.37 [0.30, 0.44], 0.27 [0.17, 0.37], 0.22 [0.14, 0.30], and 0.38 [0.23, 0.53]. Seizure-free rates were 0.04 [0.03, 0.06], 0.04 [0.03, 0.05], 0.03 [0.02, 0.05], 0.03 [0.02, 0.03], 0.02 [0.01, 0.03], and 0.04 [0.01, 0.06]. Proportion of adverse events were 0.72 [0.61, 0.83], 0.62 [0.42, 0.81], 0.60 [0.41, 0.79], 0.35 [0.14, 0.56], 0.83 [0.75, 0.90], and 0.96 [0.94, 0.99]. The pooled 12-, 24-, 48-, 96-, and 144-week proportion of serious adverse events were 0.15 [0.09, 0.21], 0.23 [0.14, 0.31], 0.10 [0.06, 0.15], 0.31 [0.24, 0.38], and 0.40 [0.35, 0.45]. Subgroup analyses showed that there was no significant difference on efficacy and safety among age subgroups and epilepsy syndromes subgroups. For most periods, there were no significant difference on efficacy among subgroups of dose and concomitant ASMs. However, higher doses and more concomitant ASMs were associated with higher proportion of adverse events.

Conclusion

Cannabidiol treatment of DRE has stable efficacy and fewer adverse events in early period. Long-term use may have decreased efficacy and increased adverse events. Dose escalation may not increase efficacy, but may increase adverse events. Furthermore, cannabidiol use may reduce dosage of other ASMs without reducing efficacy, thereby reducing adverse effects. Cannabidiol may have similar effects in various epilepsy syndromes.

Trial registration

PROSPERO (CRD42022351250).

Real-World Evidence of Factors Affecting Cannabidiol Exposure in Children with Drug-Resistant Developmental and Epileptic Encephalopathies

The identification of factors that affect cannabidiol (CBD) systemic exposure may aid in optimizing treatment efficacy and safety in clinical practice. In this study, we aimed to correlate CBD plasma concentrations at a steady state to demographic, clinical, and pharmacological characteristics as well as seizure frequency after the administration of a purified CBD oil solution in a real-world setting of children with drug-resistant developmental and epileptic encephalopathies (DEEs). Patients receiving oral CBD pharmaceutical products at maintenance were enrolled. Venous blood samples were drawn before the CBD morning dose, 12 h apart from the last evening dose (C0 or CBD trough concentration). A linear mixed-effect analysis was implemented to assess the correlation between C0 and clinical, laboratory, pharmacological, and lifestyle factors. Fifteen females and seven males with a median age of 12.8 years (ranging between 4.7 and 17.2) were included. The median CBD dose was 8.8 mg/kg/day (ranging between 2.6 and 22.5), and the CBD C0 median (range) was 48.2 ng/mL (3.5-366.3). The multivariate model showed a 109.6% increase in CBD C0 in patients with concomitant levothyroxine (β = 0.74 ± 0.1649, p < 0.001), 56.8% with food (β = 0.45 ± 0.1550, p < 0.01), and 116.0% after intake of a ketogenic diet (β = 0.77 ± 0.3141, p < 0.05). All patients included were responders without evidence of an association between C0 and response status. In children with DEEs, systemic concentrations of CBD may be significantly increased when co-administered with levothyroxine, food, or a ketogenic diet.

Cannabidiol as an adjuvant treatment in adults with drug-resistant focal epilepsy

Cannabidiol oil (CBD) has been approved as an anti-seizure medication for the treatment of uncommon types of epilepsy, occurring in children: Dravet syndrome, Lennox-Gastaut syndrome, and Tuberous Sclerosis Complex. There are few publications in relation to use the CBD in adult patients with focal drug-resistant epilepsy. The objective of this study was to evaluate the efficacy, tolerability, safety, and quality of life, of adjuvant treatment with CBD, in adult patients with drug-resistant focal epilepsy for at least 6 months. An open, observational, prospective cohort study was conducted using a before-after design (time series) in adult patients undergoing outpatient follow-up in a public hospital in Buenos Aires, Argentina. From a total of 44 patients, 5% of patients were seizure-free, 32% of patients reduced more than 80% of their seizures and 87% of patients reduced 50% of their monthly seizures. Eleven percent presented a decrease of less than 50% in seizure frequency. The average final dose was 335 mg/d orally administered. Thirty-four percent of patients reported mild adverse events and no patient reported severe adverse effects. At the end of the study, we found in most patients a significant improvement in the quality of life, in all the items evaluated. Adjuvant treatment with CBD in adult patients with drug-resistant focal epilepsy was effective, safe, well tolerated, and associated with a significant improvement in their quality of life.

Cannabidiol in children with treatment-resistant epilepsy with myoclonic-atonic seizures

PURPOSE

This multicenter study aimed to evaluate the efficacy and tolerability of add-on cannabidiol (CBD) in treatment-resistant patients with epilepsy with myoclonic-atonic seizures (EMAtS) (n = 22) and Sturge Weber syndrome (SWS) with myoclonic-atonic seizures (n = 4).

METHODS

Patients who met the diagnostic criteria of treatment-resistant EMAtS or SWS with myoclonic-atonic seizures were included. Cannabidiol was added in doses ranging from 8 to 40 mg/kg/day. Efficacy was assessed by comparing seizure frequency before and after initiating CBD therapy. Neurologic examinations, brain magnetic resonance imaging, repeated prolonged electroencephalography (EEG) and/or video-EEG recordings, and neurometabolic studies were performed in all patients, and genetic investigations in 15.

RESULTS

After a mean follow-up of 19 months, 15/26 patients (57.7%) who received add-on CBD had a >50% seizure decrease; three (11.5%) became seizure-free. The remaining 11 patients (42.3%) had a 25-50% seizure reduction. Drop attacks, including myoclonic-atonic seizures and generalized tonic-clonic seizures, as well as atypical absences and nonconvulsive status epilepticus responded well to CBD. In SWS patients, focal motor seizures without consciousness impairment and focal non-motor seizures with consciousness impairment were recognized in two each; in three a 30% reduction of focal seizures was observed. Side effects were mild and did not lead to CBD discontinuation.

CONCLUSION

This study evaluating the use of add-on CBD in children with EMAtS or SWS with myoclonic-atonic seizures found that 15/26 (57.7%) had a >50% seizure reduction with good tolerability; three (11.5%) became seizure-free.

CDKL5-associated developmental and epileptic encephalopathy: A long-term, longitudinal electroclinical study of 22 cases

OBJECTIVE

The study was conducted to analyze the possible diagnostic value of the electroclinical semiology of the epileptic seizures.

METHODS

We evaluated the medical records of 17 females and 5 males with CDKL5 deficiency disorder (CDD) considering the long-term evolution, including the polygraphic video-EEG recordings.

RESULTS

We recognized three disease phases. We found that the seizure semiology was already recognizable in the first phase of the syndrome. In the short-term evolution, all patients had focal motor and 12/21 hypermotor seizures. Both epileptic spasms and myoclonic seizures were already present in more than half of the cases in the first 2 months after onset. In the second phase, the intermediate period, the polymorphic pattern was maintained, but in eight patients the electroclinical pattern of epileptic encephalopathy with hypsarrhythmia appeared. In the long-term period, the seizure polymorphism continued but myoclonic and epileptic spasms diminished. Tonic seizures appeared in the last 2 phases. Progressively, with the aggravation of seizures and paroxysmal EEG abnormalities impairment of the neurocognitive status was observed. Severe behavioral disturbances were seen in eight and autistic-like features in 14.

CONCLUSION

CDD is a true developmental and epileptic encephalopathy with a specific etiology characterized by the early appearance of epileptic seizures that quickly become polymorphic and drug resistant in infants that are most often female and already have neurological impairment. Polygraphic video-EEG recordings are important to recognize ictal events of the association of hypermotor seizures, epileptic spasms in clusters, and massive myoclonic jerks, already present at onset.

Cannabis-based magistral formulation is highly effective as an adjuvant treatment in drug-resistant focal epilepsy in adult patients: an open-label prospective cohort study

INTRODUCTION

The safety and efficacy of a formulation high in cannabidiol (CBD) and low in ∆⁹-tetrahydrocannabinol (THC) to treat drug-resistant epilepsy have been examined previously in children, but not in adult population. The aim of this study was to evaluate whether CBD-rich oil, as an add-on treatment to conventional antiepileptic drugs, was effective, safe, and well-tolerated in adults with drug-resistant focal epilepsy (DRFE).

METHODS

An open-label, prospective cohort, single-center in adult patients with DRFE, were receiving stable doses of antiepileptic drugs (AEDs). A cannabis based-magistral formulation (CBMF) (100 mg/ml CBD and THC <1.9 mg/ml) was administrated 0.1 ml sublingually every 12 hours, up-titrated weekly. The primary outcome was to establish a reduction in seizures frequency >50% at 12 weeks. Adverse-drug reactions monitoring was done. p-value <0.05 was statistically significant.

RESULTS

Between August 2020 and July 2022, 44 (38.6%) patients completed >3 months of follow-up. The median daily dose of CBD was 200 mg, that of THC was 4 mg, and that of CBD per kilogram of weight was 3.7 mg. The median number of seizures per month before CBD treatment was 11, and after CBD treatment was 2.5 (p<0.001). A reduction in seizures >50% at 12 week was achieved in 79.5% of the patients. The median percentage change in seizure frequency per month was 84.1% at 12 weeks. Five patients reported any adverse-drug reactions.

CONCLUSION

The CBMF is a highly effective and safety therapy to treat adult patients with DRFE. The reduction in seizures frequency is maintained over time.

Clinical and Functional Study of a De Novo Variant in the PVP Motif of Kv1.1 Channel Associated with Epilepsy, Developmental Delay and Ataxia

Mutations in the KCNA1 gene, encoding the voltage-gated potassium channel Kv1.1, have been associated with a spectrum of neurological phenotypes, including episodic ataxia type 1 and developmental and epileptic encephalopathy. We have recently identified a de novo variant in KCNA1 in the highly conserved Pro-Val-Pro motif within the pore of the Kv1.1 channel in a girl affected by early onset epilepsy, ataxia and developmental delay. Other mutations causing severe epilepsy are located in Kv1.1 pore domain. The patient was initially treated with a combination of antiepileptic drugs with limited benefit. Finally, seizures and ataxia control were achieved with lacosamide and acetazolamide. The aim of this study was to functionally characterize Kv1.1 mutant channel to provide a genotype–phenotype correlation and discuss therapeutic options for KCNA1-related epilepsy. To this aim, we transfected HEK 293 cells with Kv1.1 or P403A cDNAs and recorded potassium currents through whole-cell patch-clamp. P403A channels showed smaller potassium currents, voltage-dependent activation shifted by +30 mV towards positive potentials and slower kinetics of activation compared with Kv1.1 wild-type. Heteromeric Kv1.1+P403A channels, resembling the condition of the heterozygous patient, confirmed a loss-of-function biophysical phenotype. Overall, the functional characterization of P403A channels correlates with the clinical symptoms of the patient and supports the observation that mutations associated with severe epileptic phenotype cluster in a highly conserved stretch of residues in Kv1.1 pore domain. This study also strengthens the beneficial effect of acetazolamide and sodium channel blockers in KCNA1 channelopathies.

Use of sulthiame as add-on therapy in children with myoclonic atonic epilepsy: A study of 35 patients

PURPOSE

The aim of this retrospective study was to evaluate efficacy and tolerability of sulthiame (STM) as add-on treatment in 35 patients with myoclonic atonic epilepsy (MAE) resistant to other antiseizure medications (ASMs) and/or non-pharmacological treatment.

METHODS

Patients were selected according to the diagnostic definition of MAE and were resistant to at least four previous to ASM, alone or in combination. Neurologic examinations, brain magnetic resonance imaging, and repeated prolonged electroencephalography (EEG) or video-EEG studies as well as neurometabolic studies were performed in all cases. Genetic studies were performed in 15 patients. Data on school achievements and/or neuropsychological evaluations were obtained over a mean follow-up of 30 months. Sulthiame was added in doses ranging from 10 to 30 mg/kg/day. Efficacy was assessed by comparing seizure frequency before and after initiating STM therapy.

RESULTS

Twenty-one of 35 patients (60%) who received STM as add-on therapy had a greater than 50% seizure decrease after a mean follow-up of 30 months. Complete seizure freedom was achieved in two patients (5.8%). The remaining 14 patients (40%) had a 25-50% seizure reduction. Adverse effects, consisting of hyperpnea and dyspnea, decreased appetite, nausea, drowsiness, headache, and irritability, were observed in 11 (31.4%). The adverse effects were mild and transient in all cases. Discontinuation of STM was not necessary.

CONCLUSION

Add-on STM led to a more than 50% seizure reduction in 21 of 35 patients with MAE with only mild or moderate adverse effects.