Researchers from the Ohio State University found that individuals with Lennox-Gastaut syndrome (LGS) who took cannabidiol every day for 14 weeks saw the frequency of atonic seizures fall by more than 50 percent.
Atonic seizures, also known as drop seizures, involve a sudden, brief loss of muscle tone.
Study co-author Dr. Anup Patel, of the College of Medicine at Ohio State, and colleagues recently presented their findings at the American Academy of Neurology's 69th annual meeting, held in Boston, MA.
LGS is one of the most severe forms of epilepsy. The condition involves multiple types of seizures, including tonic, atonic, atypical absence, and myoclonic.
According to the National Institutes of Health (NIH), the onset of LGS normally occurs between the ages of 3 and 5 years, and the condition is estimated to affect between 1 in 50,000 and 1 in 100,000 children in the United States.
There is no cure for LGS, and the condition is extremely challenging to treat, as there is no one-size-fits-all approach. Anti-epileptic medications, such as valproate and lamotrigine, can help to control seizures, but many children who initially respond to such drugs develop tolerance to them later on.
However, the new study from Dr. Patel and colleagues suggests that cannabidiol may be a promising treatment strategy for LGS, after finding that the cannabis compound more than halved atonic seizure frequency in patients with the condition.
Cannabidiol and epilepsy
Cannabidiol is one of the more than 80 cannabinoids, or active chemicals, present in the cannabis plant.
Research has suggested that cannabidiol has therapeutic potential, with studies linking the chemical to reductions in anxiety and improvements in bipolar disorder, schizophrenia, and other mental health conditions.
Studies have also indicated that cannabidiol may be a promising treatment strategy for epilepsy.
Dr. Patel and team decided to explore this association further by conducting a double-blind, placebo-controlled trial that assessed the effect of cannabidiol on patients with LGS.
The study involved 225 patients of an average age of 16 who had around 85 atonic seizures each month as a result of LGS.
All patients had failed to respond to an average of six anti-epileptic medications, and during the 14-week study period, they were using an average of three anti-epileptic drugs.
Throughout the duration of the study, patients were required to take either 10 or 20 milligrams of cannabidiol or a placebo every day, in combination with their current medications.
Atonic seizures more than halved with daily cannabidiol
Patients who took 10 milligrams of cannabidiol daily experienced a 37 percent reduction in atonic seizures overall, and 36 percent of these patients saw their atonic seizures reduced by at least 50 percent.
The effect was stronger with the higher cannabidiol dose; patients who took 20 milligrams of cannabidiol daily experienced an overall atonic seizure reduction of 42 percent, while a minimum of 50 percent reduction in atonic seizures was found for 40 percent of these patients.
Among patients who took the placebo, there was an overall reduction in atonic seizures of 17 percent, while 15 percent of patients saw their atonic seizures reduced by at least half.
Compared with patients taking the placebo, those taking cannabidiol were up to 2.6 times more likely to report improvements in their overall condition, say the authors.
Around 94 percent of patients taking the higher cannabidiol dose and 84 percent taking the lower dose experienced side effects, the researchers report. However, the researchers say that the majority of these side effects were mild to moderate, with the most common being a reduction in appetite and sleepiness.
Overall, Dr. Patel and colleagues believe that their results indicate that cannabidiol may be beneficial for patients with LGS.
"Our results suggest that cannabidiol may be effective for those with Lennox-Gastaut syndrome in treating drop seizures. This is important because this kind of epilepsy is incredibly difficult to treat.
While there were more side effects for those taking cannabidiol, they were mostly well-tolerated. I believe that it may become an important new treatment option for these patients."
Dr. Anup Patel
The researchers plan to submit a New Drug Application later this year to the U.S. Food and Drug and Administration (FDA), proposing cannabidiol as a treatment for LGS.