Introduction

Cannabidiol (CBD) is a new and upcoming treatment option for epilepsy. This tends to be an option for people who haven’t responded well to the usual treatment options. This report will explore how CBD can prevent seizure relapses in people who have epilepsy. 

What are epilepsy and seizures?

Epilepsy is a chronic brain disorder whereby neurons release sudden bursts of electrical activity that result in seizures.¹ These neurons create the electrical and chemical signals that affect other neurons to create our feelings and actions, but sometimes these misfire. Around 1 in 107 people in the UK are affected by epilepsy; in total that is roughly 625,800 people both young and old. 

When someone is having a seizure, the neurons in the brain send multiple signals at a time. This happens at a much faster rate than usual. Consequently, this increase in electrical activity causes movements and behaviours that are out of your control. You may also become temporarily unaware of your surroundings, caused by the imbalance of nerve cell activity. Depending on the individual and the type of seizure, some may recover straight away from the seizures, whilst others may take a little longer. 

Different types of seizures

There are different types of seizures; the main two are focal and generalised seizures.²

Focal seizures

These types of seizures start on one side of the brain and can cause changes such as a change in behaviour and awareness, and you may experience unusual movements that only affect one side of the body. The seizure can spread to the other side of the brain, if this does occur, it will result in a loss of movement and consciousness on both sides of the body. There are also two further types of focal seizures: Focal onset aware seizures and focal impaired awareness seizures.

Focal onset seizures don’t result in a loss of awareness. There is a possibility you will still be able to talk and recall what happened before and during the seizures. It may cause feelings of deja vu, an odd sensation in your stomach and some abnormal movements.

In contrast, focal impaired awareness seizures do result in a loss of awareness. You may experience confusion, be unable to respond to questions for a couple of minutes and may also pick at clothing. 

Generalised seizures 

Different types of generalised seizures are differentiated by whether movements and awareness are affected. The most common types are generalised non-motor seizures and generalised motor seizures. 

Generalised non-motor seizures are short, random periods of loss of consciousness and often go unnoticed. It causes people to stare blankly and display different hand movements. Generalised motor seizures cause a loss of awareness and cause muscles to stiffen or spasm. They may last a few minutes and result in confusion following the seizure. 

Current treatment available 

Anto-epileptic medication helps to reduce the electrical activity in the brain, thereby reducing seizures. There are many different types of medications, such as:

• Sodium channel blockers - Lamotrigine reduces the level of sodium in the brain helping to stop cells from becoming overexcited
• Clobazam helps to increase the levels of a specific neurotransmitter, which helps to create a calming feeling
• Zonisamide acts on many different aspects of the brain to try and prevent seizures

The Epilepsy Society UK (2023) reports that about 7 in 10 people with epilepsy can become seizure-free with the right medicine. However, some people might need to try different medicines before finding the one that works best for them.

Doctors choose specific medicines based on:

• The type of seizures you have
• Other medicines you might be taking
• Your age and lifestyle
• Possible side effects

What is CBD?

Cannabinoid (CBD) is found in plants. It is not considered an intoxicating substance as there is no psychoactive activity associated with it. It does however have anti-inflammatory and analgesic effects, hence, the medical use of CBD has been explored. It is different to the recreational CBD as this has the psychoactive component known as tetrahydrocannabinol (THC).³

Key Points About Medical CBD:

• Highly purified
• Contains precise, controlled amounts
• Prescribed by specialists
• Undergoes strict quality control
• Legal when prescribed

How can CBD prevent seizure relapse?

CBD has many effects that help to reduce and control seizures.⁴ For example;

• It can help to calm overactive brain cells. CBD helps to reduce any unnecessary and increased electrical activity that may trigger seizures. It specifically targets the calcium levels
• CBD can decrease inflammation, which in turn helps to prevent damage to brain cells
• CBD also has antioxidant effects that help to protect brain cells
• When CBD is used with traditional medication used to treat epilepsy, it can increase the effectiveness of that medication

As beneficial as CBD may be, there are also some points to be aware of:

• CBD should only be used if advised by a healthcare professional
• CBD is not a replacement for your usual medication but used in addition to it
• Medical CBD is not the same as recreational cannabis
• It may not be effective for everyone

Side effects and safety

The most common side effects include:

• Diarrhoea
• Tiredness
• Reduced appetite
• Minor to mild changes to liver function 

The side effects are not usually serious, however, if you are taking CBD to reduce the relapse rate of seizures as an epileptic, you would require regular blood tests to monitor the function of your liver and to see how it interacts with your other anti-epileptic medication. 

Patient selection criteria:

• Failed response to at least two standard anti-epileptic medications
• Under specialist neurological care
• Regular monitoring available
• No significant liver problems
• No history of adverse reactions to cannabis-based products⁵

Clinical evidence from UK research

Epidiolex studies

The strongest evidence comes from trials of Epidiolex (known as Epidiolex in other countries), the first CBD medicine licensed in the UK for epilepsy. Key findings from UK-based research include:

• Great Ormond Street Hospital study (2019)⁶
• 40% reduction in seizure frequency in children with complex epilepsy
• Sustained effects over 12 months
• Published in the British Journal of Clinical Pharmacology

Further studies:

• Significant reduction in drop seizures
• Improved quality of life scores
• Better sleep patterns reported⁷

Real-world evidence

NHS data from epilepsy clinics across the UK (2021-2022) shows:

• 63% of patients prescribed CBD experienced fewer seizures
• 27% reported significant improvements in daily functioning
• Reduced need for emergency hospital visits

Summary

CBS is a new and upcoming treatment option to prevent seizure relapse in individuals with epilepsy. It is especially beneficial for those who have not responded well to the current treatment options that are available.

CBD, which is used for medical purposes, differs from the recreational type as it is much more pure and controlled. It acts on the brain in various ways to help prevent a relapse of seizures. It can help to reduce the overactivity of brain cells. CBD works best when used alongside standard medication. 

Seventy per cent of people can become seizure-free if they are on the right medication, however, the treatment efficacy varies for each individual. Approximately 30% of people are still likely to have a relapse. To figure out the best treatment option, there are many factors to consider, such as what type of seizure you experience, lifestyle, age and any side effects. 

CBD shows great potential but requires careful monitoring and should be used under medical guidance. It is not a replacement but rather an additional support. Further research is needed to explore how it interacts with other medications and how to manage the side effects. Despite this, it can help a lot of people trying to prevent their seizures but to no avail.