Updated: Apr 26
Whilst epilepsy is the most common cause of seizures, they may result from many other problems. This blog post looks at the different causes of seizures, and how you might manage them as a first aider.
The words seizure, convulsion and fit are all commonly used to describe the same thing, and are used interchangeably.
A seizure can be described as an involuntary contraction and relaxation of the muscles, producing rigidity and violent shaking, with a lowered level of consciousness.
Whilst Epilepsy is the most common cause that most people are aware of, other causes of seizures are:
Low blood sugar
Psychogenic Non-Epileptic Seizures (PNES)
Infection in young children
Eclampsia in the later stages of pregnancy
Let’s look at each of these in turn…
Epileptic seizures are caused by abnormal electrical activity in the brain. There are many types of seizure, depending on where in the brain the activity is happening, but common types of seizure are:
The classic Hollywood seizure and most common in Epilepsy. The ‘tonic’ phase is where the body goes rigid, followed by the ‘clonic’ phase of rhythmic shaking. People will often have their eyes open but will not respond to commands.
As their respiratory muscles are also seizing, the person will not be breathing normally and their lips may turn blue. The person may also be incontinent as their bladder and bowel muscles are also involved.
Seizures normally last for only a minute or two, and are followed by a ‘post-ictal’ phase, where the person is drowsy and confused. However, if a seizures last for 5 minutes or more, or if the person has multiple seizures without full recovery in-between, then they may be experiencing ‘convulsive status epilepticus’ – a serious medical emergency that requires rapid professional intervention.
A focal seizure occurs when the electrical activity is in only one part of the brain. This leads to localised symptoms which may be in just one limb, or may even appear like a nervous tick or repetitive behaviour. A focal seizure may become a tonic-clonic seizure if the electrical activity spreads across the brain.
Absence seizures last for just a few seconds and the person appears as if they are day-dreaming and won’t respond to you.
People with epilepsy often know when they are about to have a seizure. This is called an aura and may allow the person to lie themselves down somewhere safe before they start convulsing. If this is not the case, the person may sustain superficial injuries from falling over or banging in to things.
People with epilepsy will often have a ‘normal’ pattern to their seizures, and may also often have a care plan that details what should be done if they have a seizure. This may include medication, which you should have been trained to administer.
Physiological Causes (Irritation of the Brain)
There are of course other physiological causes of seizures. The brain is a sensitive organ and needs things to be within pretty tight tolerances. The following problems may cause a seizure:
blow to the head
low blood sugar
low oxygen levels
meningitis or other serious infection
chemical imbalance in the blood
high pressure inside the skull
The cause of these seizures is often discovered by asking questions about the person and what happened. Have they recently banged their head? Are they a known diabetic?
Psychogenic Non-Epileptic Seizures (PNES)
Psychogenic non-epileptic seizures, as the name suggests, do not have a physiological cause. Instead, these seizures are an involuntary psychological response to distress, often associated with previous emotional trauma, such as child abuse or events which may cause PTSD.
People who experience PNES have often been misdiagnosed as having epilepsy that doesn’t respond to medication. In fact...
research suggests that up to 23% of people diagnosed with epilepsy may have been misdiagnosed
...that's about 90,000 people in the UK every year!
Epileptic seizures and PNES have features which may help to differentiate them from one another. The table below summarises these differences:
Whilst these are only 'typical' presentations, they're a pretty good way to tell the difference.
If you experience someone having a seizure, it’s worth noting these features and passing them on to healthcare professionals so that an accurate diagnosis can be made. It may even be worth recording the seizure for this purpose, if it's appropriate.
Fainting is a transient loss of consciousness caused by a temporary disruption to the supply of oxygen and glucose to the brain, due to a drop in blood pressure.
This temporary drop in blood pressure is often due to benign problems such as:
being too hot
standing still for too long
standing up too quickly
However, it can also be due to more sinister causes, such as a heart problem, although this is less likely.
People who faint will often feel dizzy, have visual or hearing distortions and become sweaty just before they collapse. When they collapse, some people will experience seizure like activity, often with vigorous shaking or stiffening of the arms and neck for up to 20 seconds, until normal blood flow to the brain is resumed.
Alcohol can cause seizures through several mechanisms. Simply being very drunk can cause someone to reduce their level of consciousness, which my precipitate a seizure.
Equally, chronic alcohol use can predispose someone to seizures and alcohol withdrawal can precipitate them.
Up to 1 in 20 children aged 6 months to 5 years will experience a febrile convulsion.
In children of this age, the part of the brain that deals with thermo-regulation (the hypothalamus) is not yet fully developed. An illness can then lead to a rapid rise in core body temperature, which can cause a seizure.
Two thirds of children who have a febrile convulsion will only ever have one episode. The other third may have further seizures during subsequent infections.
Regardless of the cause of a seizure, the first aid treatment is broadly the same.
Take a note of when the seizure started
Call an ambulance if you don’t know the person, or if the person isn’t known to have seizures
Protect the casualty from hurting themselves – cushion their head
Try to protect their dignity – they probably won’t want lots of people watching them
Try to find out the cause of the seizure
Notice the features of the seizure, perhaps film it if appropriate
Take note of how long the seizure lasts
Call an ambulance if you know the person has seizure but this one is different to normal
If the person is groggy after their seizure, put them in the recovery position to maintain their airway – see this post for more details.
In summary, whilst most seizures are due to epilepsy, there are many other causes of seizures, which may have been mis-diagnosed as epilepsy.
Seizures have a range of presentations which may help to differentiate the cause.
Whilst someone is having a fit, protect them from harm and call an ambulance if necessary.
If you’d like to know more about seizures and what to do, why not check out our range of first aid courses.