Seizures explained: Generalised seizures

We continue our blog series looking at the different types of seizures. In this second part, our Helpline and Information Officer, Uschi Stickroth, focuses on generalised seizures. 

Everyone knows a tonic-clonic seizure, right? Someone suddenly drops to the floor without warning and starts convulsing.

It’s what you usually see in films and on TV programmes when someone has a seizure.

Not surprising then that the public often assume that all seizures are the same, and all seizures look like a tonic-clonic seizure.

Please help us debunk some of the seizure myths by sharing our blogs.

Previously, we talked about focal seizures, which only affect one part of the brain. In this blog, I will take you through some of the more common generalised seizures.

These are seizures where both halves of the brain are affected at the same time and where you will always lose consciousness, even just for a brief moment:


Tonic-clonic seizures

Some people still refer to a tonic-clonic seizure as a grand mal seizure.

Just before a tonic-clonic seizure, you may experience some unusual sensations, which can often act as a warning, and may give you enough time to sit down. After the seizure, you won’t remember what’s happened.

So, what happens in a tonic-clonic seizure?

First, muscles stiffen, which makes a person fall to the ground.

This is known as the tonic phase. Then convulsions start, which is the clonic phase.

Breathing may become irregular and as a result the person’s lips could turn slightly blue.

The person may also make grunting noises, bite their tongue or cheek, or may become incontinent (lose control over their bladder or bowel).

After a couple of minutes, the jerking normally stops and the person will slowly recover.

They may feel groggy, sleepy or confused for some time afterwards. They may also have a headache or sore arms or legs. Full recovery can take a few hours to a few days.


Absence seizures

Some people still refer to an absence seizure as ‘petit mal’. These seizures are more common with children and young people and seem to affect girls/women more than boys/men.

During this type of seizure, a person will experience a brief loss of consciousness, often for only a few seconds, but because it’s so brief, the loss of consciousness is not obvious.

In fact, the first thing you may notice is that the person has suddenly stopped what they are doing and stare into space.

People with absence seizures can have them many times a day and can be mistaken for day-dreaming, especially with children.


Atonic seizures

You might have heard of drop attacks. These are atonic seizures. Your body will suddenly go limp because your muscles loosen, and you will drop to the floor.

This type of seizure is short, and the person will usually get up quickly.


Tonic seizures

The opposite happens with a tonic seizure. Muscles will suddenly stiffen, go rigid and breathing stops. If unsupported or standing, the person will fall to the floor.


Myoclonic seizures

Myoclonic seizures are sudden muscle spasms or jerks affecting arms, head and sometimes the whole body. They commonly happen in the morning just after waking or when tired.

Most people have experienced these muscle jerks. For example, just before going to sleep your leg might suddenly twitch. This is completely normal, and it doesn’t necessarily mean you have epilepsy.


Contact us

Our seizures explained factsheet provides more information. You can download this here or contact us on our helpline 0808 800 2200 or if you want a copy posted to you.

You are of course also welcome to contact our freephone helpline on 0808 800 2200, if you want to talk about your seizures and the way they affect you.