Generalised seizures

Generalized seizures are a common type of seizure in which abnormal electrical impulses affect the whole brain, temporarily preventing it carrying out its usual function. These are different from another type of seizure known as focal (or partial) seizures, where only a part of the brain is affected.

Symptoms of general seizures can vary, and may cause someone to lose consciousness, their bodies and limbs may become rigid and they may have jerking movements. Afterwards, they may feel very sleepy and take some time to regain their full level of consciousness.

Epilepsy is the most common condition causing seizures an fits – around 1% of the UK population has it - and is diagnosed if you suffer persistent seizures and are likely to continue getting seizures. Anti-epileptic medication is available to reduce the chance of future seizures.

There are 6 main types of generalised seizures;

• Absences. These mainly affect children (but can occur in adults) and cause the person to become unaware of their surroundings, sometimes looking as if they are staring into space or daydreaming. This typically lasts for 10-15 seconds and afterwards they have no memory of the event, which can happen several times a day. This means that things like school performance and tasks such as crossing the road can be affected.

• Myoclonic seizures. This type of seizure often happens in the hours after waking and causes the body and limbs to twitch for a few seconds. You remain awake the whole time if this occurs.

• Clonic seizures. The symptoms here are the same as with myoclonic seizures, but they last longer – for a minute or two – and you can lose consciousness with this type of seizure.

• Atonic seizures. These are sudden and cause all the body muscles to instantly relax, meaning you can fall to the ground without warning.

• Tonic seizures. In this type, unlike with atonic seizures, all the muscles of the body suddenly become very stiff. This means you can also fall to the ground suddenly as a result of losing your balance.

• Tonic-clonic seizures. This is the type of seizure that most people would call ‘an epileptic fit’ and has two stages. First, the body becomes very stiff, and this is followed by generalised twitching of the arms and legs, sometimes with incontinence of urine (wetting yourself). It causes you to become unconscious, and usually lasts a minute but sometimes longer.

People may have warning signs that a seizure is about to happen, and this is called an aura. This is because abnormal electrical activities can start in one part of the brain before spreading to the whole brain.

If seizures last longer than 5 minutes this is a medical emergency and you need to call 999 for urgent medical attention. If this is a first seizure for someone, they should also get an ambulance to hospital urgently.

What triggers a seizure?

Many people who have seizures can’t identify any particular triggers, but others can be sensitive to certain conditions – either within themselves or the environment – that make a seizure more likely. Poor sleep, stress, certain medications, alcohol and street or party drugs and flashing lights are all well-known triggers for a seizure.

Keeping a diary can be helpful in identifying potential triggers.