Although there are many popular medical uses for CBD, by far the one that has received the most societal attention, and that has garnered the most support in states which are strict as far as their Cannabis policy, is its use as an anticonvulsant. Since the 1970s, it has been perceived and studied at varying rates that CBD is highly effective in the treatment of major seizures, and mildly effective in the treatment of minor seizures. In addition it has proven to have a potentiating effect on other anticonvulsant medications. So how does CBD work its magic for epileptic patients? Read on…
What causes seizures?
To understand how CBD works as an anticonvulsant, first you need a basic understanding of what causes seizures. In general, the area of the brain responsible for movement and the areas for higher cognitive function become overstimulated. There are many evolutionary safeguards against this, so that is why there are several different kinds of seizure disorders. Because the brain is a giant network of neurons that are all interconnected in some way, shape, or form, the neurons that are active for one function must be insulated and divided from neurons that perform other functions.
For example, around 45% of people experience a sudden urge to sneeze when they walk into bright sunlight from a dark building. This is because in that portion of the population, the optic nerve travels directly through the sneeze reflex in the olfactory bulb of the brain. A heavy impulse on the optic nerve can bleed into the neurons of the sneeze reflex, resulting in the urge to sneeze at the sun. This is a basic analogy of how many seizures occur. The brain works by sending an electrical charge from one neuron onto the next and the next one and the one after that. It does this using calcium and sodium ions among some others (an ion is simply a molecule with a positive or negative electrical charge). How easily a neuron can send a charged ion across its cell membrane and to the next neuron is called excitability.
In people with seizure disorders, neurons fire stronger signals than they should. In addition, they are more excitable as well. Neuron A fires signals that are stronger than they should be. The signal is so strong that it hops onto neuron B, and because of higher excitability, neuron B amplifies this when it definitely shouldn’t, and a seizure occurs.
Activity in one part of the brain is stronger than it should be, so it seeps into a section of the brain near to it. Because the neurons are easily excitable, this weak crossover becomes amplified causing abnormal signalling and producing a seizure.
Most anticonvulsants work by reducing the excitability of neurons, but not the signal strength. This means that a charge from neuron A would normally cause a seizure in neuron B, but the medication has reduced the excitability of neuron B. The way the different anticonvulsants achieve this effect varies widely.
CBD is Different
It works to block seizures in many ways in addition to reducing excitability. One way that CBD works is to elevate or decrease cellular levels of ions and maintain a balance so that over-stimulation from outside the neuron doesn’t lead to over-excitation within the neuron.
Its agonization of serotonin receptors can also mimic the inhibiting effect that serotonin has on the neurons around it, thereby reducing excitability and promoting a calm alertness. Not only does this limit the likelihood that one neuron will produce a large uncontrolled signal that has collateral unintended effects on the neurons next to it, but it reduces the excitability of the latter, limiting the likelihood that a seizure would occur even if over-stimulation does occur.
Additionally, only the latest research has discovered that CBD can reduce the rate at which the brain removes adenosine molecules from neurons. Adenosine is the main neurotransmitter that produces the feeling of being tired, and is closely related to the circadian rhythm, which we know is modulated partially by the endocannabinoid system. Caffeine is an antagonist of adenosine receptors, which renders the receptor unable to experience the sedating effect of adenosine. CBD does the opposite of caffeine; it prevents adenosine from being metabolized, leaving more of it in the brain to sedate neurons and promote neuronal homeostasis.
The relevant majority of anti-seizure medication works only by one mechanism of action. The combination of the three mechanisms of CBD that you just read about, coupled with several other physiological tricks up its sleeve, work synergistically to promote the absence of seizures by reducing hyperactivity in addition to hyperexcitability. It is likely this very combination that makes CBD so much more effective than traditional single-mechanism approaches to treatment.