Epilepsy refers to a group of disorders characterized by recurrent seizures that may or may not be seizure. Cannabis and cannabis therapies have been shown to have beneficial effects on various types of epilepsy through a variety of biological mechanisms.
About 60 percent of all epileptic seizures are seizures, which means they are characterized by rapid, involuntary muscle contractions that can cause the entire body to shake or twitch uncontrollably. The most common type is tonic-clonic seizure, which involves a short period of limb contraction followed by dilation and uncontrolled tremor. In addition, there may be a period of unconsciousness before normalcy returns.
Both seizures and non-seizures are caused by over-activity of neurons in the brain; severe and persistent seizures can damage brain tissue, especially in young children, when the brain is still developing.
Dravet syndrome is a form of severe childhood epilepsy that can lead to neurological damage. It is one of the rarer forms of epilepsy, and the mortality rate for people with Dravet syndrome is 15 to 20 percent. However, there are many types of epilepsy, and although Dravet syndrome is one of the most severe, there are also mild forms of epilepsy.
Due to the ban in the 1970s, cannabis as a drug went unnoticed until recently. The recreational aspect of cannabis took precedence over public discourse, and while many knew that cannabis had some medicinal properties, it was banned for medicinal use. Now, old research is reviving, especially with regard to its effects on epilepsy, opening up new avenues for medical cannabis as an active drug.
1. Anticonvulsant effects of cannabis.
The anticonvulsant properties of cannabis have been known to humans for centuries, if not millennia. Cannabinoids were tested by researchers for their anticonvulsant effects back in 1947.
An early study from the University of Sydney in 1974 showed that high doses of delta-9-THC had an anticonvulsant effect in mice subjected to chemical and electrical shock as a seizure-inducing agent. CBD has been found to increase the anticonvulsant effects of delta-9-THC, although researchers have not been able to prove that CBD is effective on its own.
Since then, various studies have shown that CBD actually has remarkable anticonvulsant properties and enhances the effects of Delta-9-THC. A 2001 study showed that delta-9-THC and the synthetic delta-9-THC analog WIN 55.212-2 exert their effects by docking with CB1 receptors. CBD exerts its effects in a different way, as it only acts as a weak CB-1 receptor antagonist.
Due to its effect on the CB1 receptors of the central nervous system, delta-9-THC can in rare cases actually cause seizures, while CBD does not seem to have this side effect due to its independent mechanism of action.
The exact mechanism by which CBD works in seizures is not yet known, but it has been shown to be very effective in treating various types of epilepsy, including Dravet syndrome in young children, and quickly became a potential cure due to its lack of psychoactivity.
2. The neuroprotective effect of cannabis in epilepsy.
As research continues on the endocannabinoid system, it is becoming clear that it plays an important role in regulating the duration and frequency of seizures. In fact, there is an entire school of thought that suggests that epilepsy is actually caused by dysfunction of the endocannabinoid system (a condition speculatively known as clinical endocannabinoid deficiency), which can result from brain injury, infection, or genetic predisposition. This school of thought was developed by cannabis researcher Dr. Ethan Russo, as well as other neurological conditions such as Parkinson’s disease, multiple sclerosis and Dravet syndrome.
In 2008, a study published in the journal Nature found that patients with temporal lobe epilepsy had distinctly dysfunctional endocannabinoid systems. As the name suggests, temporal lobe epilepsy affects the temporal lobes of the brain and usually does not cause seizures associated with certain sensory disturbances (visual, acoustic, olfactory, or even gustatory), although in severe cases it can cause tonic-clonic seizures.
Over-stimulation of neurons in the brain is a common cause of seizures and non-seizures, and the area of the brain affected varies with the type of epilepsy. In healthy people, the endogenous cannabinoids anandamide and 2-AG are thought to play a fundamental role in regulating the level of nerve stimulation and thereby reduce the likelihood of an attack.
For example, in patients with a dysfunctional endocannabinoid system, cannabis-based treatments can be used against the causes of epilepsy and provide neuroprotective effects that reduce the severity and frequency of symptoms.
3. Protection against status epilepticus.
In extremely severe cases of epilepsy, a condition called status epilepticus can develop. Status epilepticus can include continuous seizures that last more than 30 minutes or occur with a frequency of more than one seizure in five minutes without full consciousness in between.
If the patient is not given immediate medical attention during an episode of status epilepticus, continued loss of normal brain function can lead to brain damage or even death. With proper medical care, patients with epilepsy usually survive an episode of status epilepticus without serious complications.
However, there is evidence that cannabinoids – especially CB1 receptor agonists such as anandamide, delta-9-THC, and the synthetic analogue WIN 55.212-2 – may provide better protection against status epilepticus. In a 2006 study published in the Journal of Pharmacology, WIN 55.212-2 demonstrated the ability to completely suppress all seizure activity, including prolonged episodes associated with status epilepticus.
The study also showed that WIN 55.212-2 suppressed status epilepticus significantly better than phenytoin and phenobarbital.
From this and other related studies over the past decade, CB1 receptor agonists are known to be of fundamental importance in stopping seizures and preventing the onset of status epilepticus. Research also confirms that there is a very strong correlation between the endocannabinoid system and neural stimulation that leads to status epilepticus.
For example, a 2007 study showed that when epileptic neurons were exposed to CB1 receptor antagonists, it caused continuous epileptic activity, as seen in patients with status epilepticus. Then, with treatment with CB1 receptor agonists, the overactivity ceased. Conversely, when non-epileptic neurons were treated with CB1 receptor antagonists, no excessive activity resembling status epilepticus was observed.
GW Pharmaceuticals Grant of $ 1 Million for Cannabis Epilepsy Research.
A University of Readings study identified three compounds that could be used for therapeutic control of seizures. Cannabidiol (CBD), ∆9-tetrahydrocannabivarin (THV), and GWP42006 significantly reduced the number and severity of seizures in rats. Ultimately, researchers are using cannabis to find compounds that can completely eliminate seizures. The use of cannabis as a form of therapy for epilepsy has been controversial in the past, especially in cases where epilepsy affects children. However, over the past few decades, scientists have conducted research to better understand the medical uses of cannabis in cases of epilepsy. One example is a $ 1 million grant from the University of Redin from GW Pharmaceuticals.
Researchers at the University of Reading have identified three compounds that have potential for use in therapeutic seizure control. Cannabidiol (CBD), ∆9-tetrahydrocannabivarin (THV), and GWP42006 significantly reduced the number and severity of seizures in rats. Ultimately, researchers use cannabis to find chemical compounds that can eliminate seizures completely.
The Charlotte Network and the Rise of Cannabis Use in Childhood Epilepsy.
One of the earliest human studies on the effects of cannabis on epileptic patients was conducted in the 1980s, but has only continued in the past decade. In fact, cannabis has been excluded from any repertoire as a potential epilepsy agent, and in fact the use of cannabis in this way has been frowned upon. In addition, there is controversy over the use of medical cannabis in pediatric patients.
Then, in 2009, the Stanley brothers began producing a high-CBD strain called Charlotte’s Web. It was designed specifically to treat a patient with childhood epilepsy named Charlotte. Soon after she was born, she developed frequent and severe seizures. She was diagnosed with Dravet syndrome. As soon as Charlotte started taking the new strain (CBD-THC ratio : 30 : 1), her seizures almost immediately decreased in severity and frequency.
Josh Stanley, one of the founders of the Charlotte Network, told CNN: “The biggest misconception about treating a child like Charlotte is that most people think that patients get high from cannabis.”
“This is one of the biggest obstacles for families and researchers in understanding cannabis and its medicinal use for epilepsy. The effects of cannabis on epilepsy are currently one of the most well-studied uses of cannabis for medical purposes. As research continues, cannabis is increasingly recognized and prescribed as a medication for certain types of epilepsy, especially with seizures.”