Epileptic seizures

In focal preserved consciousness (previously called focal aware seizures) the person is conscious, will usually know that something is happening and can respond and will remember the seizure afterwards. Some people find it hard to put their focal preserved consciousness seizures into words. During the seizure, they may feel ‘strange’ but not be able to describe the feeling afterwards. This may be upsetting or frustrating for them.

Focal impaired consciousness seizures (previously called focal impaired awareness seizures) affect a bigger part of one hemisphere (side) of the brain than focal preserved consciousness seizures.

The person’s consciousness is affected and they may be confused. They might be able to hear you, but not fully understand what you say or be able to respond to you. They may not react as they would normally. If you speak loudly to them, they may think you are being aggressive, and so they may react aggressively towards you.

Focal impaired consciousness seizures often happen  in the temporal lobes but can happen in other parts of the brain.

After the seizure, the person may be confused for a while. This is sometimes called ‘post-ictal’ (after-seizure) confusion.

It may be hard to tell when the seizure has ended. The person might be tired, and want to rest. They may not remember the seizure afterwards. 

•    making lip-smacking or chewing movements, repeatedly picking up objects or pulling at clothes;
•    suddenly losing muscle tone and limbs going limp or floppy, or limbs suddenly becoming stiff;
•    repetitive jerking movements that affect one or both sides of the body;
•    stiffness or twitching in part of the body, (such as an arm or hand);
•    making a loud cry or scream; or
•    making strange postures or repetitive movements such as cycling or kicking.

• a ‘rising’ feeling in the stomach or déjà vu (feeling like you’ve ‘been here before’);
• getting an unusual smell or taste;
• a sudden intense feeling of fear or joy;
• a strange feeling like a ‘wave’ going through the head;
• a feeling of numbness or tingling;
• a sensation that an arm or leg feels bigger or smaller than it actually is; or
• visual disturbances such as coloured or flashing lights or hallucinations (seeing something that isn’t actually there).

Sometimes focal seizures spread from one side to both sides of the brain. This is called a focal to bilateral tonic-clonic seizure (previously called a secondarily generalised tonic clonic seizure). When this happens the person becomes unconscious and will usually have a tonic clonic (jerking or shaking) seizure. When focal seizures spread very quickly, the person may not be aware that it started as a focal seizure.

These are the seizures most people think of as epilepsy.

At the start of the seizure:

• the person becomes unconscious;
• their body goes stiff, and if they are standing up they usually fall backwards;
• they may cry out; and
• they may bite their tongue or cheek.

During the seizure:

• they jerk and shake as their muscles relax and tighten rhythmically;
• their breathing might be affected and become difficult or sound noisy;
• their skin may change colour and become very pale or bluish; and
• they may wet themselves.

After the seizure (once the jerking stops):

• breathing and colour usually returns to normal; and 
• they may feel tired, confused, have a  headache, or want to sleep.

A person’s seizures usually last the same length of time each time they happen, and stop by themselves. However, sometimes seizures do not stop, or one seizure follows another without the person recovering in between. If this goes on for five minutes or more it is called status epilepticus, or ‘status’. Status is not common, but can happen in any type of seizure and the person may need to see a doctor. Status in a tonic clonic seizure is a medical emergency, and the person will need urgent medical help. It is important to call for an ambulance. See below for what to do if someone has a seizure.

Clonic seizures involve repeated rhythmical jerking movements of one side or part of the body or both sides (the whole body) depending on where the seizure starts. Seizures can start in one part of the brain (focal with observable manifestations) or affect both sides of the brain (generalised clonic).

In a tonic seizure the person’s muscles suddenly become stiff. If they are standing they often fall,  usually backwards, and may injure the back of their head. Tonic seizures tend to be brief and happen without warning. In an atonic seizure (or ‘drop attack’) the person’s muscles suddenly relax, and they become floppy. If they are standing they often fall, usually forwards, and  may injure the front of their head or face. Like tonic seizures, atonic seizures tend to be brief and happen without warning. With both tonic and atonic seizures people usually recover quickly, apart from possible injuries. 

Myoclonic means ‘muscle jerk’. Muscle jerks are not always due to epilepsy (for example, some people have them as they fall asleep). Myoclonic seizures are brief but can happen in clusters (many happening close together in time), and often happen shortly after waking.

In myoclonic seizures the person is conscious, but they can be classified as focal or as generalised seizures. This is because they may be followed by a generalised seizure (such as a tonic clonic seizure).

In this type of seizure, the person briefly loses muscle tone and may lose their balance and fall or struggle to regain their balance. They may lose their grip on objects and drop them. Negative myoclonic seizures can sometimes be a symptom of an epilepsy syndrome.

Absence seizures are more common in children than in adults, and can happen very frequently.

During a typical absence the person becomes blank and unresponsive for a few seconds. They may appear to be ‘daydreaming’. The seizures may not be noticed because they are brief. The person may stop what they are doing, look blank and stare, or their eyelids might blink or flutter. They will not respond to what is happening around them. If they are walking they may carry on walking, but will not be aware of what they are doing. 

Atypical absences are similar to typical absences (see above) but they start and end more slowly, and last a bit longer than typical absences. As they also include a change in muscle tone, where the limbs go limp or floppy, some people may fall.