fMRI study of cannabidiol-induced changes in attention control in treatment-resistant epilepsy

Cannabidiol-enriched oil for adult patients with drug-resistant epilepsy: Prospective clinical and electrophysiological study

OBJECTIVE

Cannabidiol-enriched oil (CBDO) is being used increasingly to improve seizure control in adult patients with drug-resistant epilepsy (DRE), despite the lack of large-scale studies supporting its efficacy in this patient population. We aimed to assess the effects of add-on CBDO on seizure frequency as well as on gait, cognitive, affective, and sleep-quality metrics, and to explore the electrophysiological changes in responder and non-responder DRE patients treated with add-on CBDO.

METHODS

We prospectively recruited adult DRE patients who were treated with add-on CBDO. Patients were evaluated prior to treatment and following 4 weeks of a maintenance daily dose of ≈260 mg CBD and ≈12 mg Δ9-tetrahydrocannabinol (THC). The outcome measures included seizure response to CBDO (defined as ≥50% decrease in seizures compared to pre-CBDO baseline), gait testing, Montreal Cognitive Assessment (MoCA), Hospital Anxiety and Depression Scale (HADS), and sleep-quality questionnaire assessments. Patients underwent electroencephalography (EEG) recording during rest as well as event-related potentials (ERPs) during visual Go/NoGo task while sitting and while walking.

RESULTS

Nineteen patients were recruited, of which 16 finished pre- and post-CBDO assessments. Seven patients (43.75%) were responders demonstrating an average reduction of 82.4% in seizures, and nine patients (56.25%) were non-responders with an average seizure increase of 30.1%. No differences in demographics and clinical parameters were found between responders and non-responders at baseline. However, responders demonstrated better performance in the dual-task walking post-treatment (p = .015), and correlation between increase in MoCA and seizure reduction (r = .810, p = .027). Post-CBDO P300 amplitude was lower during No/Go-sitting in non-responders (p = .028) and during No/Go-walking in responders (p = .068).

SIGNIFICANCE

CBDO treatment can reduce seizures in a subset of patients with DRE, but could aggravate seizure control in a minority of patients; yet we found no specific baseline clinical or electrophysiological characteristics that are associated with response to CBDO. However, changes in ERPs in response to treatment could be a promising direction to better identify patients who could benefit from CBDO treatment.

Off-label use of cannabidiol in genetic epileptic and developmental encephalopathies: A case report

Developmental Epileptic encephalopathies (DEEs) are severe neurological conditions where cognitive functions appear modulated by both seizure and interictal epileptiform activity. Cannabidiol (CBD) has been shown to be highly effective in the treatment of drug-resistant seizures in patients with DEEs. Along with its antiseizure effects, CBD demonstrated clinical beneficial effects in patients' quality of life, sleep and numerous adaptive behaviors. However, based on the available phase III studies, the indications for this treatment have so far been restricted to Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS) and tuberous sclerosis complex (TSC) by regulatory authorities. We present the case of a 30-year-old girl with a rare genetic DEE, experiencing relevant seizure frequency reduction together with striking improvement in sleep quality, mood, behavior, language and motor skills after introducing off-label CBD.

Altered dynamic functional connectivity of motor cerebellum with sensorimotor network and default mode network in juvenile myoclonic epilepsy

Objective

To investigate whether changes occur in the dynamic functional connectivity (dFC) of motor cerebellum with cerebral cortex in juvenile myoclonic epilepsy (JME).

Methods

We adopted resting-state electroencephalography-functional magnetic resonance imaging (EEG-fMRI) and a sliding-window approach to explore the dFC of motor cerebellum with cortex in 36 JME patients compared with 30 and age-matched health controls (HCs). The motor cerebellum was divided into five lobules (I-V, VI, VIIb, VIIIa, and VIIIb). Additionally, correlation analyses were conducted between the variability of dFC and clinical variables in the Juvenile Myoclonic Epilepsy (JME) group, such as disease duration, age at disease onset, and frequency score of myoclonic seizures.

Results

Compared to HCs, the JME group presented increased dFC between the motor cerebellum with SMN and DMN. Specifically, connectivity between lobule VIIb and left precentral gyrus and right inferior parietal lobule (IPL); between lobule VIIIa and right inferior frontal gyrus (IFG) and left IPL; and between lobule VIIIb and left middle frontal gyrus (MFG), bilateral superior parietal gyrus (SPG), and left precuneus. In addition, within the JME group, the strength of dFC between lobule VIIIb and left precuneus was negatively (r = -0.424, p = 0.025, Bonferroni correction) related with the frequency score of myoclonic seizures.

Conclusion

In patients with JME, there is a functional dysregulation between the motor cerebellum with DMN and SMN, and the variability of dynamic functional connectivity may be closely associated with the occurrence of motor symptoms in JME.

The latest advances in the pharmacological management of focal epilepsies in children: a narrative review

INTRODUCTION

Focal epilepsy constitutes the most common epilepsy in children, and medical treatment represents the first-line therapy in this condition. The main goal of medical treatment for children and adolescents with epilepsy is the achievement of seizure freedom or, in drug-resistant epilepsies, a significant seizure reduction, both minimizing antiseizure medications (ASM)-related adverse events, thus improving the patient's quality of life. However, up to 20-40% of pediatric epilepsies are refractory to drug treatments. New ASMs came to light in the pediatric landscape, improving the drug profile compared to that of the preexisting ones. Clinicians should consider several factors during the drug choice process, including patient and medication-specific characteristics.

AREAS COVERED

This narrative review aims to summarize the latest evidence on the effectiveness and tolerability of the newest ASMs administered as monotherapy or adjunctive therapy in pediatric epilepsies with focal onset seizures, providing a practical appraisal based on the existing evidence.

EXPERT OPINION

The latest ASMs have the potential to be effective in the pharmacological management of focal onset seizures in children, and treatment choice should consider several drug- and epilepsy-related factors. Future treatments should be increasingly personalized and targeted on patient-specific pathways. Future research should focus on discovering new chemical compounds and repurposing medications used for other indications.

Cannabidiol (CBD) drives sex-dependent impairments in omission, but has no effect on reinforcer devaluation

Habits are inflexible behaviors that persist despite changes in outcome value. While habits allow for efficient responding, neuropsychiatric diseases such as drug addiction and obsessive-compulsive disorder are characterized by overreliance on habits. Recently, the commercially popular drug cannabidiol (CBD) has emerged as a potential treatment for addictive behaviors, though it is not entirely clear how it exerts this therapeutic effect. As brain endocannabinoids play a key role in habit formation, we sought to determine how CBD modifies goal-directed behaviors and habit formation. To explore this, mice were administered CBD (20mg/kg i.p.) or vehicle as a control and trained on random interval (RI30/60) or random ratio (RR10/20) schedules designed to elicit habitual or goal-directed lever pressing, respectively. Mice were tested for habitual responding using probe trials following reinforcer-specific devaluation as well as omission trials, where mice had to withhold responding to earn rewards. We found that while CBD had little effect on operant behaviors or reward devaluation, CBD inhibited goal-directed behavior in a sex-specific and contextdependent manner during the omission task. Beyond drug treatment, we found an effect of sex throughout training, reward devaluation, and omission. This work provides evidence that CBD has no effect on habit formation in a reward devaluation paradigm. However, the omission results suggest that CBD may slow learning of novel actionoutcome contingencies or decrease goal-directed behavior. This work calls for further examination of sex-dependent outcomes of CBD treatment and highlights the importance of investigating sex effects in habit-related experiments.

A scoping review on cannabidiol therapy in tuberous sclerosis: Current evidence and perspectives for future development

Cannabidiol (CBD) has recently been approved as an add-on therapy by various regulatory agencies for tuberous sclerosis complex (TSC)-associated seizures based on its short-term efficacy and safety in a pivotal randomized controlled trial. However, critical information about which patients with TSC and seizure types respond best to CBD (clinical, electrophysiological, and genetic predictors of responsiveness), when to use CBD in the treatment algorithm, and how CBD can be combined with other antiseizure medications (ASMs) in the form of a rational polypharmacy therapy is still lacking. In general, there is a limited in-depth critical review of CBD for the treatment of TSC to facilitate its optimal use in a clinical context. Here, we utilized a scoping review approach to report the current evidence of efficacy and safety of pharmaceutical-grade CBD in patients with TSC, including relevant mechanism of action and drug-drug interactions with other ASMs. We also discussed emerging information about CBD's long-term efficacy and safety data in patients with TSC. Finally, we discussed some critical unanswered questions in several domains related to effective clinical management of TSC using CBD, including barriers to early and aggressive treatment in infants, difficulty with universal access to CBD, a lack of studies to understand CBD's impact on seizure severity and specific seizure types, insufficient exploration of CBD in TSC-related cognitive and behavioral issues, and the need for more research into CBD's effects on various biomarkers.

Precentral gyrus and insula responses to stress vary with duration to diagnosis in functional seizures

OBJECTIVE

This study was undertaken to determine whether undiagnosed illness duration (time between functional seizures [FS] onset and diagnosis) is linked to differences in neural response and functional connectivity during processing of stressful experiences.

METHODS

Forty-nine participants with traumatic brain injury preceding the onset of FS confirmed by video-electroencephalography were recruited prospectively. Participants completed psychiatric symptom assessments before undergoing functional magnetic resonance imaging (fMRI) with an acute psychosocial stress task. Linear mixed effects (LME) analyses identified significant interactions between the factors of group (early vs. delayed diagnosis) and time lag to diagnosis on neural responses to stressful math performance and auditory feedback (corrected α = .05). Functional connectivity analysis utilized clusters from initial LME analyses as seed regions to determine significant interactions between these factors on network functional connectivity.

RESULTS

Demographic and psychiatric symptom measures were similar between early (n = 25) and delayed (n = 24) groups. Responses to stressful math performance within the left anterior insula and functional connectivity between the anterior insula seed region and a precentral gyrus cluster were significantly negatively correlated with time lag to diagnosis for the early but not the delayed FS diagnosis group. There was no correlation between fMRI findings and psychiatric symptoms.

SIGNIFICANCE

This study indicates that aberrant left anterior insula activation and its functional connectivity to the precentral gyrus underlie differences in processing of stressful experiences in patients with delayed FS diagnosis. Follow-up comparisons suggest changes are associated with undiagnosed illness duration rather than psychiatric comorbidities and indicate a potential mechanistic association between neuropathophysiology, response to stressful experiences, and functional neuroanatomy in FS.

Longitudinal neurodevelopmental profile of a pediatric patient with de novo SPTAN1, epilepsy, and left hippocampal sclerosis

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We present the first longitudinal study of neuropsychological functioning in a pediatric patient with SPTAN1.

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To our knowledge we report the first case of SPTAN1 heterozygosity in a patient with MTLE due to HS.

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This case is the first to show that lisdexamfetamine dimesylate improved attention, behavior, and school performance in a patient with heterozygous SPTAN1 variant.

Pathogenic variants in SPTAN1 result in abnormal neurodevelopment but limited information is available on the spectrum of neurodevelopmental profiles associated with variations in this gene. We present novel data collected at two time points over a three-year period in a nine-year-old patient with heterozygous de novo SPTAN1 variant, drug-resistant epilepsy, and left hippocampal sclerosis. Across evaluations, our patient’s performance was highly variable, ranging from below age expectation to within age-expected range. The patient exhibited relative cognitive strengths at both time points on verbal-expressive tasks. Weaknesses were seen in her attention, executive function, psychomotor processing speed, fine motor, visual-motor integration, and social skills. Memory findings were consistent those associated with left hippocampal sclerosis. Evaluations resulted in diagnoses including attention deficit hyperactivity disorder and autism spectrum disorder.

Clinical Approaches to Cannabis: A Narrative Review

Cannabis use in the United States is growing at an unprecedented pace. Most states in the United States have legalized medical cannabis use, and many have legalized nonmedical cannabis use. In this setting, health care professionals will increasingly see more patients who have questions about cannabis use, its utility for medical conditions, and the risks of its use. This narrative review provides an overview of the background, pharmacology, therapeutic use, and potential complications of cannabis.

A feasibility study to assess social stress and social support in patients enrolled in a cannabidiol (CBD) compassionate access program

Cannabidiol (CBD) trials offer an opportunity to examine social factors that shape outcomes of patients with treatment-resistant epilepsy. Prior research of patients treated with CBD for epilepsy describes financial struggles of these patients/families and the association between socioeconomic status and patient-centered outcomes. However, social determinants of health in this population are still poorly understood, mainly due to data scarcity. This study aimed to establish feasibility of assessing social stress, social support, and religious participation and their associations with outcomes (perceived health, quality of life, and mood) in patients treated with CBD for epilepsy. Data were collected during 2015-2018 through structured face-to face interviews with patients/caregivers in a CBD compassionate access/research program in the southern United States. Adult (ages 19-63; n = 65) and pediatric (ages 8-19; n = 46) patients or their caregivers were interviewed at the time of enrollment in the study. Social stress was assessed with stressful life events, perceived stress, epilepsy-related discrimination, and economic stressors; social support with the Interpersonal Support Evaluation List [ISEL]-12; and religious participation with frequency of religious attendance. The results showed economic stressors to be associated with poor overall health, but no associations were noted between stress, support, and religious participation measures and quality of life or mood. Despite a robust data collection plan, completeness of the data was mixed. We discuss lessons learned and directions for future research and identify potential refinements to social data collection in people with treatment-resistant epilepsy during clinical trials.

Potential Role of Cannabidiol on Sports Recovery: A Narrative Review

The use of cannabidiol (CBD) among athletes is becoming extensive and frequent. This could be due to the elimination of CBD from the list of prohibited substances by federations and international institutions of sport. The legalization and resulting production, and commercialization of CBD, could increase its intake in sports professionals. This commercialization of cannabinoids has fueled a race to study their properties, benefits, and risks for health and performance in athletes. Although there is evidence that suggests some beneficial properties such as anxiolytics, antidepressants, anti-inflammatory, and antioxidants among others, the evidence presented so far is neither clear nor conclusive. There are significant gaps in knowledge of the physiological pathways that explain the role of CBD in sports performance. This mini-review examines evidence suggesting that CBD has the potential to be used as a part of the strategies to recover from fatigue and muscle damage related to physical and cognitive exertion in sports.

Relationships between cognitive function, seizure control, and self-reported leisure-time exercise in epilepsy

Exercise may be a strategy for improvement of cognitive deficits commonly present in people with idiopathic generalized epilepsies (IGE). We investigated the relationship between cognition and level of physical exercise in leisure (PEL) in people with IGE who have been seizurefree for at least 6 months (IGE-) as compared to those who have not been seizurefree (IGE+) and healthy controls (HCs). We hypothesized that higher level of physical exercise is associated with better cognitive functioning in patients with IGE and HCs, and that seizure control affects both PEL levels and cognitive functioning in patients with IGE. We recruited 75 participants aged 18-65: 31 people with IGE (17 IGE-, 14 IGE+) and 44 HCs. Participants completed assessments of quality of life (SF-36), physical activity levels (Baecke questionnaire and International Physical Activity Questionnaire (IPAQ)) and cognition (Montreal Cognitive Assessment (MoCA), Hopkins Verbal Learning Test - Revised (HVLT), and flanker task). Group differences (HCs vs. IGE; HCs vs. IGE+ vs. IGE-) were assessed. Pearson correlations examined linear relationships between PEL and cognitive performance. Groups were similar in age and sex. Compared to HCs, patients with IGE had higher body mass index, fewer years of education, and consistently scored worse on all measures except flanker task accuracy on incongruent trials. When examining IGE- and IGE+ subgroups, compared to HCs, both had higher body mass index, and fewer years of education. Healthy controls scored significantly better than one or both of the IGE groups on SF-36 scores, PEL levels, IPAQ activity level, MoCA scores, HVLT learning and long-delay free-recall scores, and flanker task accuracy on congruent trials. Among patients with IGE, there were no significant differences between age of epilepsy onset, duration of epilepsy, number of anti-seizure drugs (ASDs) currently being used, or the group distribution of type of IGE. In the combined sample (IGE+, IGE- and HCs), PEL positively correlated with MoCA scores (Pearson's r = 0.238; p = 0.0397) and with flanker task accuracy on congruent trials (Pearson's r = 0.295; p = 0.0132). Overall, patients with IGE performed worse than HCs on cognitive and physical activity measures, but the cognitive impairments were more pronounced for IGE+, while physical exercise levels were less for patients with IGE regardless of seizure control. While positive relationships between leisure-time PEL and cognitive performance are promising, further investigations into how exercise levels interact with cognitive functioning in epilepsy are needed.

A Mini-Review of Relationships Between Cannabis Use and Neural Foundations of Reward Processing, Inhibitory Control and Working Memory

Cannabis is commonly used, and use may be increasing in the setting of increasing legalization and social acceptance. The scope of the effects of cannabis products, including varieties with higher or lower levels of Δ9-tetrahydrocannabinol (THC) or cannabidiol (CBD), on domains related to addictive behavior deserves attention, particularly as legalization continues. Cannabis use may impact neural underpinnings of cognitive functions linked to propensities to engage in addictive behaviors. Here we consider these neurocognitive processes within the framework of the dual-process model of addictions. In this mini-review, we describe data on the relationships between two main constituents of cannabis (THC and CBD) and neural correlates of reward processing, inhibitory control and working memory.

Recent Advances in Neuroimaging of Epilepsy

Human neuroimaging has had a major impact on the biological understanding of epilepsy and the relationship between pathophysiology, seizure management, and outcomes. This review highlights notable recent advancements in hardware, sequences, methods, analyses, and applications of human neuroimaging techniques utilized to assess epilepsy. These structural, functional, and metabolic assessments include magnetic resonance imaging (MRI), positron emission tomography (PET), and magnetoencephalography (MEG). Advancements that highlight non-invasive neuroimaging techniques used to study the whole brain are emphasized due to the advantages these provide in clinical and research applications. Thus, topics range across presurgical evaluations, understanding of epilepsy as a network disorder, and the interactions between epilepsy and comorbidities. New techniques and approaches are discussed which are expected to emerge into the mainstream within the next decade and impact our understanding of epilepsies. Further, an increasing breadth of investigations includes the interplay between epilepsy, mental health comorbidities, and aberrant brain networks. In the final section of this review, we focus on neuroimaging studies that assess bidirectional relationships between mental health comorbidities and epilepsy as a model for better understanding of the commonalities between both conditions.

Long-term safety and efficacy of highly purified cannabidiol for treatment refractory epilepsy

OBJECTIVE

To evaluate the safety, efficacy, and tolerability of highly purified cannabidiol (CBD) for the treatment of seizures in children and adults with treatment-resistant epilepsy (TRE) in an open-label, expanded access program (EAP).

METHODS

One hundred sixty-nine participants (89 children and 80 adults) with TRE received plant-derived highly purified CBD (Epidiolex® in the U.S.; 100 mg/mL oral solution) with a starting dose of 5 mg/kg/day divided twice per day and titrated to a maximum dose of 50 mg/kg/day over the study period to seizure control and tolerability and followed for up to 2 years. Seizure frequency (calendars) and severity (Chalfont Seizure Severity Score; CSSS) were collected at every study visit. Adverse Events were reported at/between study visits as required, and participants also completed Adverse Events Profile (AEP) which generates a numerical representation of AEs. Response to CBD was defined as ≥50% reduction in seizure frequency. Given non-normal distribution of seizure frequency, a log transformation was applied after which the generalized least squares regression model for longitudinal data was used.

RESULTS

Evidence from the adjusted model revealed a significant mean reduction in seizure frequency compared to baseline in children and adults at all time points (1 month and 1 and 2 years). Percentage of children achieving ≥50% seizure frequency reduction was 44% at month 1, and 41% at year 1, and 61% reduction at year 2, while adult responder rates were 34% at month 1, 53% at year 1, and 71% at year 2 (all P < 0.0001). CSSS showed a sustained reduction from baseline to all 3 time points. Children displayed 52% seizure reduction at month 1, a 51% reduction at year 1, and 75% reduction at year 2. Seizure reductions in adults were 60%, 81%, and 85%, respectively (all P < 0.0001). While there were no significant differences between seizure frequency reduction between children and adults at all time points, there was a significant difference in seizure severity reduction at year 1, with adults reporting greater improvement in seizure severity (P < 0.001). The most commonly reported adverse events in the study period were diarrhea, sedation, and decreased appetite. AEP revealed significant improvement from baseline at multiple time points in adults and children, and the mean AEP scores were always lower compared to baseline over the duration of the study.

SIGNIFICANCE

Our study provides further evidence of sustained seizure frequency and severity reduction over two years of treatment with highly purified CBD in TRE. In addition, CBD was generally well tolerated with minority of participants experiencing adverse events resulting in stopping CBD.

Highly Purified Cannabidiol for Epilepsy Treatment: A Systematic Review of Epileptic Conditions Beyond Dravet Syndrome and Lennox-Gastaut Syndrome

BACKGROUND

Cannabidiol (CBD), which is one major constituent of the Cannabis sativa plant, has anti-seizure properties and does not produce euphoric or intrusive side effects. A plant-derived, highly purified CBD formulation with a known and constant composition has been approved by the US Food and Drug Administration for the treatment of seizures associated with Dravet syndrome, Lennox-Gastaut syndrome, and tuberous sclerosis complex. In the European Union, the drug has been authorized by the European Medicines Agency for the treatment of seizures associated with Dravet syndrome and Lennox-Gastaut syndrome, in conjunction with clobazam, and is under regulatory review for the treatment of seizures in patients with tuberous sclerosis complex.

OBJECTIVES

This systematic review aimed to summarize the currently available body of knowledge about the use of this US Food and Drug Administration/European Medicines Agency-approved oral formulation of pharmaceutical-grade CBD in patients with epileptic conditions, especially developmental and epileptic encephalopathies other than Dravet syndrome and Lennox-Gastaut syndrome.

METHODS

The relevant studies were identified through MEDLINE and the US National Institutes of Health Clinical Trials Registry in October 2020. There were no date limitations or language restrictions. The following types of studies were included: clinical trials, cohorts, case-control, cross-sectional, clinical series, and case reports. Participants had to meet the following criteria: any sex, any ethnicity, any age, diagnosis of epilepsy, receiving plant-derived, highly purified (> 98% w/w) CBD in a sesame oil-based oral solution for the treatment of seizures. Data extracted from selected records included efficacy, tolerability, and safety outcomes.

RESULTS

Five hundred and seventy records were identified by database and trial register searching. Fifty-seven studies were retrieved for detailed assessment, of which 42 were eventually included for the review. The participants of the studies included patients of both pediatric and adult age. Across the trials, purified CBD was administered at dosages up to 50 mg/kg/day. In a randomized double-blind controlled trial in patients with tuberous sclerosis complex, CBD was associated with a significantly greater percent reduction in seizure frequency than placebo over the treatment period. Open-label studies suggested the effectiveness of CBD in the treatment of children and adults presenting with other epilepsy syndromes than those addressed by regulatory trials, including CDKL5 deficiency disorder and Aicardi, Dup15q, and Doose syndromes, SYNGAP1 encephalopathy, and epilepsy with myoclonic absences. The most common adverse events observed during treatment with CBD included somnolence, decreased appetite, diarrhea, and increased serum aminotransferases.

CONCLUSIONS

The currently available data suggest that response to treatment with a highly purified, plant-derived CBD oil-based solution can be seen in patients across a broad range of epilepsy disorders and etiologies. The existing evidence can provide preliminary support for additional research.

Functional Connectivity Derived From Electroencephalogram in Pharmacoresistant Epileptic Encephalopathy Using Cannabidiol as Adjunctive Antiepileptic Therapy

To explore brain function using functional connectivity and network topology derived from electroencephalogram (EEG) in patients with pharmacoresistant epileptic encephalopathy with cannabidiol as adjunctive antiepileptic treatment. Sixteen epileptic patients participated in the study, six of whom had epileptic encephalopathy with a stable dose of cannabidiol Epidiolex (CBD) as adjunctive therapy. Functional connectivity derived from EEG was analyzed based on the synchronization likelihood (SL). The analysis also included reconstructing graph-theoretic measures from the synchronization matrix. Comparison of functional connectivity data between each pathological group with the control group was carried out using a nonparametric permutation test applied to SL values between pairs of electrodes for each frequency band. To compare the association patterns between graph-theoretical properties of each pathological group with the control group, Z Crawford was calculated as a measure of distance. There were differences between pairs of electrodes in all frequency bands evaluated in encephalopathy epileptic patients with CBD adjunctive therapy compared with the control (p < 0.05, permutation test). In the epileptic encephalopathy group without CBD therapy, the SL values were higher than in the control group for the beta, theta, and delta EEG frequency bands, and lower for the alpha frequency band. Interestingly, patients who had CBD as adjunctive therapy demonstrated greater synchronization for all frequency bands, showing less spatial distribution for alpha frequency compared with the control. When comparing both epileptic groups, those patients who had adjunctive CBD treatment also showed increased synchronization for all frequency bands. In epileptic encephalopathy with adjunctive CBD therapy, the pattern of differences for graph-theoretical measures according to Z Crawford indicated less segregation and greater integration suggesting a trend towards the random organization of the network principally for alpha and beta EEG bands. This exploratory study revealed a tendency to an overconnectivity with a random network topology mainly for fast EEG bands in epileptic encephalopathy patients using CBD adjunctive therapy. It can therefore be assumed that the CBD treatment could be related to inhibition of the transition of the interictal to ictal state and/or to the improvement of EEG organization and brain function.

Cannabidiol in the Treatment of Epilepsy

Anecdotal reports addressing the successful seizure treatment of severe epilepsies with cannabidiol (CBD) have increased both public interest and academic research. Placebo-controlled, randomized, controlled trials proved the efficacy of pharmaceutical-grade CBD in epilepsy treatment, thus leading to pharmaceutical-grade CBD approval by the US Food and Drug Administration and the European Medicines Agency for the treatment of seizures in Dravet syndrome and Lennox–Gastaut syndrome as well as for tuberous complex syndrome by the Food and Drug Administration only. However, the CBD market is confusing because an array of products of different origins, purity, and concentration is available. Additionally, the results from the pivotal studies with plant-derived, pharmaceutical-grade CBD cannot simply be transferred to other epilepsy types or CBD of any origin. Because of the high demands and expectations that patients with epilepsy and their caregivers have regarding CBD, information outlining the proven facts and potential risks is essential. The aim of this article is to thoroughly review available research data and practical recommendations to provide the treating physician with the necessary information for counseling patients with epilepsy.

Cognitive and behavioral effects of cannabidiol in patients with treatment-resistant epilepsy

PURPOSE

Therapeutic use of cannabidiol (CBD) in intractable epilepsies has increased considerably over the last ten years. As more evidence for the potentially beneficial effects of CBD on different epilepsy types is emerging, it is important to monitor potential cognitive and behavioral side effects. So far, studies including standardized neuropsychological data in the context of treatment with CBD in epilepsy patients are sparse. The present open-label study examines cognitive and behavioral effects of CBD in children and adults with treatment resistant epilepsy.

METHOD

Thirty-nine patients with treatment-resistant epilepsy completed the study protocol, i.e. they were tested at baseline (T0) and after three months of CBD treatment (T1). Patients completed standardized neuropsychological tests on memory, executive functions and attention if they were capable. For cognitively impaired patients who could not complete cognitive tests, caregiver interviews were conducted and caregiver questionnaires completed.

RESULTS

Significant cognitive decline from T0 to T1 was observed on none of the included measures. There was a significant improvement on a measure of selective attention and on a caregiver-rated behavioral measure. More than 89% of all individual test results remained stable or showed reliable improvement from T0 to T1. Cognitive and behavioral changes from T0 to T1 were not significantly correlated with CBD dose. Improvements in short-term/working memory were significantly related to better therapy response.

CONCLUSION

No adverse group-level effects of CBD treatment were detected. On an individual level, most test results remained stable or were improved. Cognitive change was not related to CBD dose. The present results show that, from a cognitive and behavioral point of view, CBD seems to have an encouraging side-effect profile. The results need to be replicated with larger samples.

Cannabidiol in epilepsy: The indications and beyond

Epilepsy, although common, remains difficult to treat with as much as 30% of patients having treatment-resistant conditions. Lennox-Gastaut syndrome and Dravet syndrome are childhood-onset epilepsies and among the most difficult to treat. Cannabidiol has been approved by the Food and Drug Administration to treat these conditions in individuals over 2 years of age; however, there is a great deal of interest in off-label use. This article examines 3 cases: 1 of a patient with Lennox-Gastaut syndrome, 1 of off-label use of cannabidiol to treat epilepsy, and 1 of nonprescription forms of cannabidiol to treat epilepsy.

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

OBJECTIVE

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.

METHODS

Twenty-two of 27 participants with TRE completed all study procedures including longitudinal pre-/on-CBD rs-fMRI (8M/14F, mean age = 36.2 ± 15.9 years, TRE duration = 18.3 ± 12.6 years); there were no differences in age (p = 0.99) or sex (p = 0.15) between groups. Assessments collected included seizure frequency (SF), Chalfont Seizure Severity Scale (CSSS), Columbia Suicide Severity Rating Scale (C-SSRS), Adverse Events Profile (AEP), and Profile of Mood States (POMS). Twenty-three healthy controls (HCs) received rs-fMRI and POMS once.

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.

Effects of highly purified cannabidiol (CBD) on fMRI of working memory in treatment-resistant epilepsy

OBJECTIVE

We aimed to determine changes in working memory and functional connectivity via functional magnetic resonance imaging (fMRI)-modified Sternberg task after treatment with highly purified cannabidiol (CBD, Epidiolex®; 100 mg/mL) in patients with treatment-resistant epilepsy (TRE).

METHODS

Twenty patients with TRE (mean age: 35.8 years; 7 male) performed fMRI Sternberg task before receiving CBD ("PRE") and after reaching stable dosage of CBD (15-25 mg/kg/day; "ON"). Each patient performed 2 runs of the modified Sternberg task during PRE and ON fMRI. Twenty-three healthy controls (HCs; mean age: 25 years; 11 M) also completed the task. All were presented with a sequence of 2 or 6 letters and instructed to remember them (encoding). After a delay, a single letter was shown, and participants recalled if letter was shown in sequence (retrieval). Paired t-tests were used to analyze accuracy/response times. For each subject, event-related modeling of encoding (2 and 6 letters) and retrieval was performed. Paired t-tests controlling for seizure frequency change and scanner type were performed to assess changes in neural recruitment during encoding and retrieval in key regions of interest.

RESULTS

There was nonsignificant increase in mean modified Sternberg task accuracy from PRE to ON-CBD (28.6 vs. 32.1%). PRE and ON accuracy was worse than HCs (75.5%, p < 0.001). ON-PRE comparison revealed increased activation in the right inferior frontal gyrus (IFG) during 6-letter encoding. ON-HC comparison revealed increased activation in bilateral IFG and insula during 2-letter encoding. PRE-HC comparison revealed decreased activation in the left middle frontal gyrus during 6-letter encoding. None of these activations were associated with working memory performance.

SIGNIFICANCE

Treatment-resistant epilepsy results in poorer working memory performance and lower neural recruitment compared with HCs. Treatment with CBD results in no significant changes in working memory performance and in significant increases in neural activity in regions important for verbal memory and attention compared with HCs during memory encoding.

Practical use of pharmaceutically purified oral cannabidiol in Dravet syndrome and Lennox-Gastaut syndrome

INTRODUCTION

Pharmaceutically purified oral cannabidiol (CBD) has been recently approved by the US Food and Drug Administration and European Medicines Agency as treatment of seizures associated with Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS), which are severe and difficult-to-treat developmental and epileptic encephalopathies with onset in early childhood.

AREAS COVERED

This review will critically review the pharmacokinetic properties of CBD, the interactions with antiseizure and non-antiseizure medications, and the main tolerability and safety issues to provide guidance for its use in everyday practice.

EXPERT OPINION

CBD is metabolized in the liver and can influence the activity of enzymes involved in drug metabolism. The best characterized drug-drug interaction is between CBD and clobazam. The most common adverse events include somnolence, gastrointestinal discomfort, and increase in serum transaminases. High-grade purified CBD oral solution represents an effective therapeutic option in patients with DS and LGS. The findings cannot be extrapolated to other cannabis-based products, synthetic cannabinoids for medicinal use and non-medicinal cannabis and CBD derivatives.

Cognitive function and adaptive skills after a one-year trial of cannabidiol (CBD) in a pediatric sample with treatment-resistant epilepsy

OBJECTIVE

Cannabidiol (CBD) is a nonpsychoactive derivative of cannabis. Studies indicate that it is safe and effective in treating certain types of epilepsy. The present study examined the presence of adverse or beneficial cognitive or functional adaptive effects associated with CBD in the treatment of children, adolescents, and teenagers with treatment-resistant epilepsy (TRE) as part of an ongoing prospective, open-label safety study.

METHODS

Participants (N = 38) between the age of 3 and 19 years with TRE were enrolled in an open-label study of a pharmaceutical formulation of CBD (Epidiolex®; GW Research Ltd.) as an add-on treatment. In addition to baseline physical, neurological, and laboratory testing, cognitive assessment was completed prior to initiating CBD and after one year, both using the NIH Toolbox Cognition Battery (NIHTB-CB). Many participants were unable to complete the NIHTB-CB because of the magnitude of their cognitive impairment (n = 24), and in these cases, the participant's caregiver was asked to complete the Adaptive Behavior Assessment System - Second Edition (ABAS-II) as a measure of functional adaptive skills.

RESULTS

There were no statistically significant changes in cognitive function, as measured by the NIHTB-CB, in those participants who were able to complete such testing, but there was a nonsignificant trend toward improvement in some cognitive domains. For participants who were unable to complete formal standardized cognitive testing because of the magnitude of their cognitive impairment, their functional adaptive skills, as measured by the ABAS-II, were unchanged after a one-year trial of CBD.

SIGNIFICANCE

Our findings suggest that CBD, as an add-on drug for TRE in a pediatric sample, does not appear to cause adverse effects (AEs) involving cognition or adaptive function over one year of treatment.

Neuroimaging of memory in frontal lobe epilepsy

In a large percentage of epilepsies, seizures have focal onset. These epilepsies are associated with a wide range of behavioral and cognitive deficits sometimes limited to the functions encompassed within the ictal onset zone but, more frequently, expanding beyond it. The presence of impairments associated with neuroanatomical areas outside of the ictal onset zone suggests distal propagation of epileptic activity via brain networks and interconnected whole-brain neural circuitry. In patients with frontal lobe epilepsy (FLE), using functional magnetic resonance imaging (fMRI) to identify deficits in working, semantic, and episodic memory may provide a lens through which to understand typical and atypical network organization. A network approach to focal epilepsy is relevant in these patients because of the frequently noted early age of seizure onset. Early seizure-related disruption in healthy brain development may result in a significant brain reorganization, development of compensation-related mechanisms of dealing with function abnormalities and disruptions, and the propagation of epileptic activity from the focus to widespread brain areas (functional deficit zones). Benefits of a network approach in the study of focal epilepsy are discussed along with considerations for future neuroimaging studies of patients with FLE.

The anticonvulsant effects of cannabidiol in experimental models of epileptic seizures: From behavior and mechanisms to clinical insights

Epilepsy is a neurological disorder characterized by the presence of seizures and neuropsychiatric comorbidities. Despite the number of antiepileptic drugs, one-third of patients did not have their seizures under control, leading to pharmacoresistance epilepsy. Cannabis sativa has been used since ancient times in Medicine for the treatment of many diseases, including convulsive seizures. In this context, Cannabidiol (CBD), a non-psychoactive phytocannabinoid present in Cannabis, has been a promising compound for treating epilepsies due to its anticonvulsant properties in animal models and humans, especially in pharmacoresistant patients. In this review, we summarize evidence of the CBD anticonvulsant activities present in a great diversity of animal models. Special attention was given to behavioral CBD effects and its translation to human epilepsies. CBD anticonvulsant effects are associated with a great variety of mechanisms of action such as endocannabinoid and calcium signaling. CBD has shown effectiveness in the clinical scenario for epilepsies, but its effects on epilepsy-related comorbidities are scarce even in basic research. More detailed and complex behavioral evaluation about CBD effects on seizures and epilepsy-related comorbidities are required.

Efficacy and adverse event profile of cannabidiol and medicinal cannabis for treatment-resistant epilepsy: Systematic review and meta-analysis

This paper aimed to systematically examine the efficacy and adverse event (AE) profile of cannabidiol and medicinal cannabis by analyzing qualitative and meta-analytic data. We used the terms ("Cannabidiol" OR "Cannabis") AND "Epilepsy" AND ("Treatment" OR "Therapeutics") as keywords to retrieve studies indexed on PubMed, ScienceDirect, and CENTRAL databases. The inclusion criteria were as follows: clinical studies with a longitudinal observational design and intervention using cannabinoid derivatives, especially cannabidiol and medicinal cannabis, whereby some results involved the frequency of epileptic seizures. We used Cochrane Collaboration's Review Manager software (RevMan 5.1.6) for the meta-analysis and dichotomized the articles to a confidence interval of 95%. From 236 articles, we selected 16 for descriptive analysis; we selected only 4 for the meta-analysis. According to the results, a statistically meaningful effect of cannabidiol compared with placebo was observed (p < 0.00001). When comparing treatment with cannabidiol or medicinal cannabis, significance was not found for the AE profile (p = 0.74). As AEs for cannabidiol were more common under short-term than under long-term treatment (p < 0.00001), this approach was favorable in the long term. Furthermore, cannabidiol is more effective than placebo, regardless of the etiology of epileptic syndromes and dosage. Overall, the AE profile did not differ across treatments with cannabidiol or medicinal cannabis, though it did differ favorably for long-term than for short-term treatment.

A preliminary study of the effects of cannabidiol (CBD) on brain structure in patients with epilepsy

Cannabis use is associated with changes in brain structure and function; its neurotoxic effects are largely attributed to Δ⁹-tetrahydrocannabidiol. Whether such effects are present in patients with epilepsy exposed to a highly-purified cannabidiol isolate (CBD; Epidiolex®; Greenwich Biosciences, Inc.) has not been investigated to date. This preliminary study examines whether daily CBD dose of 15-25 mg/kg produces cerebral macrostructure changes and, if present, how they relate to changes in seizure frequency. Twenty-seven patients with treatment-resistant epilepsy were recruited from the University of Alabama at Birmingham CBD Program. Participants provided seizure frequency diaries (SF), completed the Chalfont Seizure Severity Scale (CSSS) and Adverse Events Profile (AEP), and underwent MRI before CBD (baseline) and after achieving a stable CBD dosage (on-CBD). We examined T1-weighted structural images for gray matter volume (GMV) and cortical thickness changes from baseline to on-CBD in 18 participants. Repeated measures t-tests confirmed decreases in SF [t(17) = 3.08, p = 0.0069], CSSS [t(17) = 5.77, p < 0.001], and AEP [t(17) = 3.04, p = 0.0074] between the two time-points. Voxel-level paired samples t-tests did not identify significant changes in GMV or cortical thickness between these two time-points. In conclusion, short-term exposure to highly purified CBD may not affect cortical macrostructure.

Health literacy and quality of life in patients with treatment-resistant epilepsy

This exploratory study examined the impact of health literacy on quality of life (QoL) in patients with treatment-resistant epilepsy (TRE). Health literacy is a discrete form of literacy in which an individual can readily interpret prose and apply that skill to understand medical, pharmaceutical, and self-management information. From the perspectives of cultural health capital (CHC) and social disability theory, we hypothesized that greater levels of health literacy would be associated with a higher QoL score. The sample (n = 79) included adult patients with TRE enrolled in the University of Alabama at Birmingham Cannabidiol Program. The data were analyzed by using nested linear regression. Respondents aged 19-63 years (mean, standard deviation [SD] = 32.9 [13.65]) and were 92% white; 44% of patients were in Special Education until age 21 years, and 29% reported a total annual family income of less than $25,000. Significant bivariate relationships were found between health literacy and QoL (p = .004), age (p = .0001), and income (p = .036). There was a significant difference in health literacy scores for patients who completed high school or less (mean [SD] = 0.68 [0.86]) and those with any postsecondary education (mean [SD] = 1.59 [1.0]). The regression results showed health literacy to be positively associated with QoL where a 1% increase in health literacy was associated with a 6.61-point increase in QoL (p = .004), and this pattern persisted through each addition of other independent factors and control variables. This is one of the first studies investigating the role of health literacy in QoL among patients with TRE. The results suggest that health literacy is important and may function as a tool through which healthcare participation is expanded. Further research is needed with larger, more diverse, and longitudinal samples to accurately model the development of health literacy and its impact on QoL in this population.