What is epilepsy?

Epilepsy is a condition that can have challenging impacts on the nervous system, particularly the brain. This condition is characterised by recurrent seizures, which are episodes of electrical activity bursts in the brain that cause uncontrollable behaviours involving movement, feeling and consciousness.¹ As of 2024, it is predicted that 50 million patients around the world are affected by epilepsy.² The brain contains many nerve cells which work together to cause you to think, move and behave. These processes are directed by complex electrical signals, and the random bursts of electrical activity that occur in epilepsy can interfere with the brains ability to form coordinated thoughts, movements and behaviours. 

Types of seizures

Focal seizures

Focal seizures happen when there is unusual electrical activity in one side of the brain and within a specific area. The specific area of your focal seizure may be in any lobe of the brain, but it most commonly occurs in one called the temporal lobe, which is responsible for your ability to sense, store and hold on to memories, as well as understanding language and emotions.

There are two kinds of focal seizures for you to be aware of:^3,4,5,6

Focal aware seizures – Your consciousness is not affected by these seizures; however, you may not be able to respond to those around you during the seizure, which often lasts two minutes. This type of seizure occurs in the frontal lobe of the brain, which is responsible for cognitive functions like decision making, problem solving and attention. Symptoms can be shaking or tingling in one part of the body (both often in the arms or legs), feeling nauseous, or seeing flashing lights.

Focal impaired awareness seizures – These are more complex compared to focal aware seizures. Your body will experience a seizure in the part of your brain which affects consciousness.

This is still on only one side of the brain and so: will affect only one side of your body. The symptoms can range from unconsciousness to more distressing events such as extreme shaking, because it affects the temporal lobe of your brain, which controls your movement and consciousness.

Generalised seizures

In contrast, generalised seizures affect both sides of your brain. They can happen without warning and there are a few types of generalised epileptic seizures to be aware of:^7,8,9,10,11

Absence seizures – When experiencing an absence seizure, you most likely will not remember much of the episode, and will recover without interference. Absence seizures do not last a long time, only an estimated fifteen seconds, which bystanders might experience it as a period of intense staring. Both sides of the brain are affected here, specifically the corpus callosum, which functions as a pathway through which the two sides of the brain can communicate with each other.

Atonic seizures – You may feel very weak because of a decrease in your muscle tone, which may cause you to collapse. Muscle tone is affected since these episodes are located in the frontal lobe and brain stem, which both have functions in regulating muscle tone.

Myoclonic seizures – These come and go instantly, since they only last a second. Myoclonic seizures are sudden jolts due to increased electrical activity in the corpus callosum. This may feel that same as jolting when you fall asleep.

Tonic-clonic seizures – These are the classic stereotyped seizures of epilepsy, where your body loses consciousness and your muscles stiffen into a spasm. Your eyes may roll back and your chest muscles may contract, challenging your ability to breathe. This difficulty in breathing may cause a gargling sound. This type of seizure lasts at least a few minutes and can cause great stress on the brain, using a lot of energy. As a result, you can often feel confused, frightened and tired immediately after these episodes. Tonic-clonic seizures occur in the outermost area of the brain called the cerebral cortex, which has the most processing units (called nerve cells) within the nervous system and is why tonic-clonic seizures are so damaging to the brain.

What is CBD?

CBD stands for cannabidiol, which is an oil extracted from the cannabis plant that may have therapeutic properties when used for disorders like epilepsy.¹²

You might be wondering whether using CBD will give you the same effects as smoking cannabis would. You can be assured that CBD will not make you feel the negative side effects like hallucination, disorientation, paranoia and mood changes, as it does not contain the substance THC (tetrahydrocannabinol).¹³ THC is the compound in cannabis that causes these negative effects. Essentially,, when you use CBD, it binds to a specific receptor (think of this like a key to a door) that blocks out the effects of THC. Instead, CBD provides a relaxing effect on your nervous system.¹⁴

How does CBD help with seizures?

There is not a very large amount of evidence as of yet regarding the effect of CBD on epileptic seizures. There is, however, data that shows that CBD acts on certain parts of the brain by reducing the nerve cell excitation. Normally, for nerve cell excitation to happen complex processes involving the release of calcium into these cells must occur. CBD has shown to decrease the release of calcium into nerve cells which in turn reduces the number of excitational electrical currents that move through your body. These are the same electrical currents that can become overexcited in an epileptic seizure.¹⁵

CBD for focal seizures

However as of 2024 there have been some promising findings for the use of CBD to treat focal seizures. Research shows that CBD may reduce the severity of the less complex focal awareness seizures, as well as the severity ofthe more complex focal impaired awareness seizures.¹⁶

CBD for generalised seizures

The effects of CBD on absence seizures have been shown to have some impact in other organisms but have yet to be taken to human trials. CBD These preliminary trials that show the potential for CBD to change certain pathways involved in seizures may be promising.¹⁷

When it comes to atonic seizures, evidence suggests that CBD usage may provide substantial reductions in seizure severity.¹⁸

Regarding myoclonic seizures, research is again limited, but there is some data that suggests a reduced intensity in these seizures. However, some of the patients involved in these trials suffered from Lennox-Gastaut Syndrome (LGS) or Dravet Syndrome (DS).¹⁷

Finally, CBD is suggested to mildly reduce seizure strength when it comes to tonic-clonic seizures. . This has been tested after other medications have failed to treat these seizures.¹⁸

Key differences in CBD’s effectiveness

Focal seizures typically have more targeted medical treatments since they only affect part of the brain at a time, compared to generalised seizures that affect both sides of the brain. The use of CBD has so far shown to be effective and well tolerated for focal seizures, specifically when other treatments have failed.¹⁹ However, since generalised seizures are included in a larger number of clinical trials than other types of seizures, the approval of CBD has been successful for this type of seizure. 

• The following points should be considered: For focal seizures, CBD might be used in the future alongside failed treatments to offer you more control over your seizures. This scientifically requires more research to confirm the positive effects, and for confirmation of safety
• Generalised seizures have well-supported data which has led to CBD being an approved treatment option for you to use

Side effects and considerations

The side effects you may suffer when using CBD as an epilepsy treatment are very similar when used for both focal and generalised seizures.

These side effects include:¹⁷

• Sleepiness, diarrhoea decreased appetite, mood changes – particularly aggression and irritation
• Change in liver function – Think of your liver as an efficient filter, which allows your body to remove certain products that may be toxic. There has been data that suggests increased liver toxicity when CBD is used alongside an epilepsy medication called valproic acid

Summary

Epilepsy is a condition that affects your brain by causing recurring seizures that can be distressing and disruptive. Seizures are episodes where your brain has excessive electrical activity, and this article discusses two forms of the condition. One form is called focal epilepsy, which only happens in one part of the brain, affecting your awareness and partially affecting your movement. Generalised epileptic seizures involve both sides of the brain and can cause sudden loss of consciousness, muscle weakness and spasms.

CBD is extracted from the cannabis plant and has offered promising results for the management of generalised epileptic seizures. Although CBD does not treat the underlying cause of epilepsy, it has been suggested to relieve seizure episodes. Despite these encouraging results, there is a long way to go regarding research into the efficacy of CBD for epileptic patients. This is nonetheless a step in the right direction.