What Causes Epilepsy?
The cause of epilepsy varies between individuals. For some individuals, there is no identifiable cause, whereas others may be due to structural brain changes or changes to channels that regulate the firing of neurons in the brain.
Some causes of epilepsy are genetic, with 1 in 3 sufferers having a family member with the condition.
For some individuals it is damage to the brain which causes epilepsy to occur. This includes damage from:
- Brain tumour
- Severe head injury
- Drug or alcohol abuse/misuse
- An infection in the brain
- Oxygen starvation at birth
People may have specific epilepsy syndromes, which are normally diagnosed during childhood. Some examples include:
- Infantile spasms (West syndrome)
- Doose syndrome (myoclonic astatic epilepsy of childhood)
- Benign rolandic epilepsy
- Rasmussen syndrome
- Lennox-Gastaut syndrome
- Electrical status epilepticus of sleep
- Dravet syndrome
- GLUT1 deficiency syndrome
- Sturge-Weber syndrome
What Causes Seizures?
During an epileptic seizure, the electrical signals in the brain become disrupted.
Seizures normally occur in individuals with epilepsy; however, it is possible to experience a seizure without having epilepsy or a seizure disorder.
For those with epilepsy, there are some common triggers which increase the likelihood of experiencing a seizure for certain individuals.
- Forgetting to take prescribed medication
- Sleep deprivation
- Drugs, including illegal recreational drugs and alcohol
Many people associate strobe or flashing lights with the onset of seizures, but this trigger is rarer than perceived.
The main symptom of epilepsy is recurrent seizures.
Seizures vary from person to person depending on which part of the brain is affected. There are several different types of seizure. The different types of seizure and their characteristics are outlined below.
Simple Partial (Focal) Seizure
Simple partial seizures occur whilst awake and aware. Symptoms include:
- Feeling odd or strange in a way that cannot be described
- Sensation in the stomach like when on a fairground ride or driving over a sudden drop in the road
- The feeling of déjà vu
- Unusual smell or taste
- Tingling sensations in the arms or legs
- Experiencing intense feelings of joy or fear
- Twitching or stiffness in a particular area of the body – often the arm or hand
Complex Partial (Focal) Seizure
Complex partial seizures are similar to simple partial seizures; however, they progress to cause a loss of self-awareness during the seizure. Symptoms include:
- Smacking the lips
- Hand rubbing
- Making random and incoherent noises
- Arm movements
- Fiddling with objects or picking at clothing
- Excessive chewing or swallowing
A person experiencing a complex partial (focal) seizure will not be able to respond to others during the episode and will have no recollection of having had a seizure.
Tonic-Clonic Seizures (formerly Grand Mal)
Tonic-clonic seizures are probably what most people envision when they think of a seizure, and they happen in 2 stages:
- Tonic stage – during this stage there will be loss of awareness and body stiffness. For those not already seated or lying down they will commonly collapse to the floor.
- Clonic stage – during this stage, the limbs jerk and the person may lose bladder/bowel control, bite the tongue or inside of the cheek, and may have difficulty breathing due to collapse of the airway.
This type of seizure normally lasts a few minutes but may last longer. Following a tonic-clonic seizure it is not uncommon to feel tired, confused, and/or experience a headache.
In addition, a person may experience just the tonic phase (known as a tonic seizure) or just the clonic stage (known as a clonic seizure).
Absence Seizures (formerly Petit Mal)
Absence seizures mainly affect children but can happen to people of all ages. During an absence seizure, there is a loss of awareness and surroundings for a short period of time. The characteristics of absence seizure are:
- Blankly staring into space
- Appearing to be in a daydream
- Eye fluttering
- Slight body or limb jerking
This type of seizure can be difficult to spot as it usually only lasts around 15 seconds, though can occur several times per day.
Lasting only a fraction of a second, a myoclonic seizure is characterised by sudden body twitching or jerking. This happens most commonly after waking up. Though short, several seizures can happen in succession.
The opposite of a tonic seizure, during an atonic seizure, the muscles in the body become suddenly very relaxed which can cause collapse. These types of seizures are usually short-lived and normal muscle function is usually restored straight away.
Status Epilepticus is the name given to any prolonged seizure lasting more than 30 minutes.
Status Epilepticus is a medical emergency, and an ambulance should be called as early as possible if a person experiences longer than usual seizures which don’t respond to rescue medications.
How is Epilepsy Diagnosed?
The first time a person has a seizure their GP will usually refer them to a neurologist to find out the cause. Neurologists are specialists in conditions affecting the brain and nerves.
They will ask questions about previous seizures, any family history of seizures, lifestyle, previous health conditions and any other relevant questions to get an overview of the person’s health and lifestyle. Additionally, they may refer the person for tests such as an electroencephalogram (EEG).
The diagnosis of epilepsy is made if it is determined that there is a likelihood of developing further seizures and that the cause isn’t due to another condition which will reduce the likelihood of seizures once treated (i.e. an acute infection).
Specific syndromes and causes of epilepsy may require more in-depth testing, including an individual’s genetics or specialist imaging of the brain.
Knowing what triggers the seizures can help to prevent them, so it is worth keeping a diary that might pinpoint certain triggers.
There are several anti-epileptic medicines that can be taken to reduce or even stop seizures altogether.
Surgery is an option for some individuals as well. However, only a small proportion of individuals are eligible for surgery. In particular, those with treatment-resistant epilepsy are often not suitable candidates.
For those not suitable for a surgical resection, the implantation of a neurostimulation device might be appropriate.
For others, a ketogenic diet might prove successful, particularly in those with an underlying metabolic disorder causing their epilepsy. However, some people do find a ketogenic diet difficult to adhere to.
The specialist and patient will work together to decide on the best treatment plan.
Medical Marijuana for Epilepsy
Research into the effect of medicinal cannabis on epilepsy is limited. However, following the legalisation of cannabis for medical purposes in 2018, there has been a rise in people looking towards medical cannabis. When first-line therapies have not proved effective at reducing symptoms, medical cannabis may be considered an option for epilepsy.
For further information and to find out more about medical cannabis, click here to discover more about our award-winning Sapphire Access Scheme. Alternatively, complete an eligibility assessment now. Once complete, one of our clinicians will review your application and advise whether you are eligible for progression to an appointment.
January 2023 Breakthrough: NHS to Offer Medical Cannabis to Treat Tuberous Sclerosis Complex (TSC)
Tuberous Sclerosis Complex is a rare genetic disorder which causes the development of benign tumours. The most common symptom of the condition is epilepsy, however, affecting 90% of those with tuberous sclerosis complex. The condition can severely affect the quality of life of sufferers and those who care for them alike. In January 2023, it was confirmed that the NHS will be able to prescribe a cannabidiol preparation called Epidyolex® to those living with TSC with ‘clinical trials showing that when used alongside standard patient care such as typical antiseizure medications, Epidyolex® reduces the frequency of seizures by almost a third (30%), increasing the number of days patients can go without a seizure compared with placebo, and lowering the risk of sudden death.’ (source: https://www.england.nhs.uk/2023/01/nhs-to-offer-licensed-cannabis-based-medicine-to-treat-rare-genetic-condition/).
Fewer and less severe seizures with higher levels of predictability give patients and families the confidence to leave the house and enjoy normal social and leisure activities, as well as attend school and other educational or work environments.