Related Experiment Video
Updated: Mar 14, 2026
Tobacco Hornworm as an Insect Model System for Cannabinoid Pre-clinical Studies
Published on: December 29, 2021
Cannabidiol as a new treatment for drug-resistant epilepsy in tuberous sclerosis complex
Evan J Hess1, Kirsten A Moody1, Alexandra L Geffrey1
1Massachusetts General Hospital, Boston, Massachusetts, U.S.A.
Objective:
Tuberous sclerosis complex (TSC) is an autosomal-dominant genetic disorder with highly variable expression. The most common neurologic manifestation of TSC is epilepsy, which affects approximately 85% of patients, 63% of whom develop treatment-resistant epilepsy. Herein, we evaluate the efficacy, safety, and tolerability of cannabidiol (CBD), a nonpsychoactive compound derived from the marijuana plant, as an adjunct to current antiepileptic drugs in patients with refractory seizures in the setting of TSC.
Methods:
Eighteen of the 56 patients who have enrolled in our current expanded-access study of cannabidiol for patients with treatment-resistant epilepsy carry a diagnosis of TSC. After an initial baseline period of 1 month, patients began treatment with CBD. The initial dose of 5 mg/kg/day was increased by 5 mg/kg/day every week up to a maximum dose of 50 mg/kg/day, if tolerated. Weekly seizure frequencies, percent change in seizure frequencies, and responder rates were calculated during the 2nd, 3rd, 6th, 9th, and 12th month of treatment with CBD.
Results:
The median weekly seizure frequency during the baseline period was 22.0 (interquartile range [IQR] 14.8-57.4), which decreased to 13.3 (IQR 5.1-22.1) after 3 months of treatment with cannabidiol. The median percent change in total weekly seizure frequency was -48.8% (IQR -69.1% to -11.1%) after 3 months of treatment. The 50% responder rates over the course of the study were 50%, 50%, 38.9%, 50%, and 50% after 2, 3, 6, 9, and 12 months of treatment with CBD, respectively. In patients taking clobazam concurrently with CBD (n = 12), the responder rate after 3 months of treatment was 58.3%, compared to 33.3% in patients not taking clobazam (n = 6). Twelve (66.7%) of 18 patients in this study experienced at least one adverse event thought possibly related to CBD; the most common adverse events were drowsiness (n = 8, 44.4%), ataxia (n = 5, 27.8%), and diarrhea (n = 4, 22.2%).
Significance:
Although double-blind, placebo-controlled trials are still necessary, these findings suggest that cannabidiol may be an effective and well-tolerated treatment option for patients with refractory seizures in TSC.
Insights
Cannabidiol (CBD) shows promise in reducing refractory seizures in Tuberous Sclerosis Complex (TSC) patients. This study indicates CBD is a potentially effective and well-tolerated adjunctive therapy for managing difficult-to-treat epilepsy in TSC.
Area of Science:
- Neurology
- Pharmacology
- Genetics
Background:
- Tuberous Sclerosis Complex (TSC) is a genetic disorder frequently causing epilepsy.
- Approximately 85% of TSC patients experience epilepsy, with 63% developing treatment-resistant forms.
- Refractory epilepsy in TSC presents a significant clinical challenge.
Purpose of the Study:
- To evaluate the efficacy, safety, and tolerability of cannabidiol (CBD) as an add-on therapy for refractory seizures in TSC patients.
- To assess CBD's impact on seizure frequency and responder rates.
- To identify potential adverse events associated with CBD treatment in this population.
Main Methods:
- An expanded-access study involving 18 TSC patients with treatment-resistant epilepsy.
- Patients received escalating doses of CBD (5-50 mg/kg/day) for up to 12 months.
- Seizure frequencies, responder rates, and adverse events were monitored weekly and monthly.
Main Results:
- Median weekly seizure frequency decreased by 48.8% after 3 months of CBD treatment.
- 50% responder rates were consistently observed at multiple time points (2, 3, 9, and 12 months).
- Common adverse events included drowsiness, ataxia, and diarrhea; 66.7% of patients reported at least one CBD-related adverse event.
Conclusions:
- Cannabidiol (CBD) demonstrates potential as an effective treatment for refractory seizures in Tuberous Sclerosis Complex (TSC).
- The findings suggest CBD is a well-tolerated adjunctive therapy for managing epilepsy in TSC.
- Further placebo-controlled trials are warranted to confirm these promising results.
More Related Videos
Related Concept Videos
01:18Antiepileptic Drugs: GABAergic Pathway Potentiators
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for...
01:20Antiepileptic Drugs: Potassium Channel Activators
Ezogabine has gained approval as an adjunctive treatment...
01:20Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein
SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for...
01:08Antiepileptic Drugs: Sodium Channel Blockers
Sodium channel blockers modulate ion channels, particularly voltage-gated sodium channels. They block only sodium ion movement.
Among the most commonly prescribed antiepileptic drugs are...
01:17Antiepileptic Drugs: Calcium Channel Blockers
Calcium channel blockers exert their antiepileptic effects by targeting T-type calcium channels, which are integral to transmitting nerve signals in the central nervous system. These channels allow the passage of calcium ions, which are vital for neuronal communication. By inhibiting T-type calcium channels, calcium channel blockers effectively reduce the release of neurotransmitters and...
01:24Epilepsy and Seizures: Overview
Various factors can trigger epilepsy, including genetic factors, brain damage, metabolic causes, and unknown etiology. Diagnosis of epilepsy involves electroencephalography (EEG), which...