Epilepsy & CBD
Cannabidiol, which is found in marijuana plants, reduced the number of convulsive seizures in children with a severe and often fatal epilepsy disorder, according to research published Wednesday in the New England Journal of Medicine. Among children taking cannabidiol, the decrease in the frequency of convulsive seizures— which involve a loss of consciousness, stiffened muscles and jerking movements — was 23 percentage points greater than the decrease in seizures among children taking a placebo.
The study was a randomized, double-blind, placebo-controlled human trial, which is considered the gold standard test for any new medicine.
Cannabidiol, also called CBD, is one of more than 80 active cannabinoid chemicals in the marijuana plant, which is classified as a Schedule I controlled substance. Unlike tetrahydrocannabinol, or THC, it does not produce a high.
GW Pharmaceuticals, a company that is developing cannabidiol medicines, helped subsidize the study.
“After 3,800 years of cannabis use for epilepsy … we finally have solid evidence,” said Dr. Orrin Devinsky, lead author of the study and director of NYU Langone’s Comprehensive Epilepsy Center. His own previous researchindicates that cannabis was used as early as 1800 B.C. in Sumeria to treat epilepsy; neurologists of the Victorian period used Indian hemp, which is rich in cannabidiol, for the same purpose.
Despite the generally positive results, most study participants reported side effects that included vomiting, fatigue, diarrhea and some liver issues.
“CBD is an effective drug for this type of rare epilepsy but was not a panacea (or cure-all) for these children,” Devinskysaid.
What is Dravet syndrome?
A total of 120 patients with Dravet syndrome, ranging in age from nearly 2 to 18 years old, were randomly assigned to receive either an oral solution of cannabidiol or a placebo for a 14-week period.
“Dravet syndrome is a severe childhood-onset epilepsy that causes multiple kinds of seizures, developmental delays, speech and language problems, behavioral issues and movement and balance problems,” said Brandy Fureman, vice president of research and new therapies at the Epilepsy Foundation. She was not involved in the new study.
Epilepsy is a neurological disorder that disrupts electrical communication between neurons in the brain. Considered a spectrum disorder, different epilepsy syndromes are defined by clusters of symptoms or features and treated accordingly.
Existing epilepsy medications usually don’t work for patients with Dravet, so “up to 20% of these children die from seizures before age 20 years,” Devinsky explained.
Within the study, individual participants experienced convulsive seizures at a rate ranging from four per month, on average, to 1,717 per month.
During the 14-week study, frequency of convulsive seizures decreased from an average of 12.4 to 5.9 per month in the cannabidiol group, compared with 14.9 to 14.1 in the placebo group. On average, the change in seizure frequency amounted to a 39% decrease for the cannabidiol group patients, compared with a roughly 13% decrease among the placebo group.
Five percent of the children became entirely seizure-free during the 14-week study. Overall, parents in the cannabidiol group felt that they witnessed “significantly greater” positive changes in their children than parents in the placebo group.
However, there was a downside. Most (93%) of the cannabidiol patients reported side effects, though three-quarters of the placebo group patients did as well. Nine out of 61 cannabidiol group patients dropped out of the study, eight of them because of side effects, compared with just three of the 59 placebo group patients.
“Tiredness (somnolence or fatigue) was most common; others were decreased appetite, diarrhea and vomiting,” Devinsky explained.
Based on the overall results, Devinsky believes CBD should be evaluated for epilepsy types beyond Dravet syndrome, which is caused by a genetic mutation and affects about one in 20,000 to 40,000 children in the United States.
Wayne Hall,professor and director of the Centre for Youth Substance Abuse Research at the University of Queensland in Australia, also believes the findings are “sufficiently encouraging” to warrant further research of cannabidiol that focuses on “related forms of epilepsy.”