Crises tonico-cloniques

What is a tonic-clonic seizure?

A tonic-clonic seizure is the most common type of generalised seizure (previously known as a "grand mal" seizure). The following gives a typical description of a tonic-clonic seizure:

• Body. Your body becomes rigid due to strong muscular contractions (the tonic part). You lose consciousness and fall.

• Chest. Your chest muscles contract and force air out of your mouth, often with a grunt.

• Jaw. Your jaw muscles contract and you may bite your tongue.

• Mouth. Saliva may escape from your mouth.

• Bladder. Your bladder may contract and you may pass urine.

• Tremblement. This stiff or tonic phase soon passes into the clonic (shaking or convulsive) phase. This occurs when the muscles repeatedly contract and relax. Your whole body appears to shake.

• Awareness. During a generalised tonic clonic seizure, you are unconscious and unaware of what is happening.

• Duration. This may last from a few seconds to a few minutes.

Grand mal seizures is an older term for generalized tonic-clonic seizures. It has essentially the same meaning, but is no longer used as often by medical professionals.

When the tonic-clonic seizure has stopped:

• You gradually regain consciousness but you may be confused and dazed for a while. The time taken to recover varies.

• You may have some soreness due to the muscular contractions.

• You may have a headache and want to sleep after a seizure.

You may have some warning symptoms for a short while before a tonic-clonic seizure.

Aura symptoms

Warning symptoms are called an aura. The aura can take various forms - for example:

• Odd movements.

• Odd sensations.

• Intense emotions.

However, many people do not have auras, and a seizure commonly occurs without any warning.

A tonic-clonic seizure cannot be shortened or altered. However, a bystander can help in the following ways:

During a tonic-clonic seizure

Do's

• Note the time.

• Prevent crowds gathering round.

• Place a cushion or some clothing under the person's head to prevent injury.

Don'ts

• Don't try to restrain the person. If there is a warning (aura) before a tonic-clonic seizure, it may be possible to guide the person to a safe place or cushion the expected fall to the ground. When the seizure starts, do not try to hold the person upright but let them lie down.

• Don't move the person unless they are in a dangerous place (for example, in a road or next to a fire). If possible, move dangerous objects away from the person.

• Don't place anything in the person's mouth or try to move their tongue.

  • People sometimes bite their tongue during a seizure - this can cause some bleeding, but isn't dangerous. Putting something in their mouth est dangerous, though, as it can cause choking.

After the tonic-clonic seizure

Do's

• Roll the person on to their side into the recovery position.

• Check that breathing has resumed normally. It is normal for breathing to stop for a short while during the stiff (tonic) part of the seizure. The face will go pale or bluish. During the convulsive (clonic) part, breathing is irregular. After the tonic-clonic seizure is over, breathing returns to normal. If not, check there is nothing stopping breathing, such as food or false teeth. The recovery position helps saliva and anything in the mouth - such as food or sick (vomit) - to drain out of the mouth and not back into the throat.

• Stay and talk to the person. Give reassurance until they are fully recovered. It may take a while for the person to wake up fully. Do not leave a person alone whilst they remain dazed or confused.

Don'ts

• Don't offer something to eat or drink until you are sure they are fully recovered.

When to call a doctor or an ambulance

You should call an ambulance if:

• It is their first tonic-clonic seizure.

• Injury has occurred which cannot be dealt with.

• The tonic-clonic seizure does not stop after a few minutes. A seizure lasting more than five minutes, or repeated seizures occurring without recovery in between, is called status epilepticus. This is an emergency and needs urgent treatment to stop the tonic-clonic seizure.

• There is difficulty with breathing after the seizure.

People who have epilepsy usually don't need to go to hospital every time they have a seizure, as long as the seizure is typical for them, they recover fully afterwards, and there are no other worrying features.

There are many different treatments for epilepsy and also medicines to help prevent people with epilepsy having seizures.

During a seizure

Most tonic clonic (grand mal) seizures stop on their own within a few minutes, and don't need any treatment to stop the seizure.

Seizures that last longer than five minutes, or repeated seizures that occur without any recovery in-between, are a medical emergency. Emergency treatment should be given to try to stop the seizure, if this happens.

Benzodiazepines can be used to try to stop the seizure. These can be given by a healthcare professional. Some forms can be given by carers or friends or family who are following an emergency treatment plan, if they have been trained in how and when to use them. Examples include:

• Buccal midazolam - a syringe containing midazolam liquid is used to place the liquid between the gums and the cheek.

• Rectal diazepam - a gel containing diazepam is inserted into the bottom (rectum).

• Intravenous lorazepam - an injection of lorazepam is given into a vein. This can only be done by a healthcare professional.

There are also other drugs which can be used by healthcare professionals if someone's seizures have not stopped after using benzodiazepines.

First choice treatment

Anti-epilepsy medications are often recommended for people with epilepsy to reduce the risk of future seizures. A neurologist should discuss the different options with you, to help decide which medication is right for you. Examples include:

Valproate de sodium

Valproate de sodium is a good first-line treatment for some people. It is effective at controlling and preventing seizures.

The main risk with sodium valproate is that it can cause birth defects if taken by pregnant women. It may also cause developmental problems in children if their father was taking sodium valproate when they were conceived.

The current UK guidelines are that sodium valproate should not be started in anyone under the age of 55 (male or female), unless two separate specialists agree that there are no other suitable alternatives, and that pregnancy is not a risk.

See also the separate leaflet called Epilepsy and Planning Pregnancy.

Lamotrigine or levetiracetam

Lamotrigine ou levetiracetam are alternatives and may be used instead of sodium valproate, especially in people who could get pregnant. They may also be used if sodium valproate does not give good enough seizure control.

Second treatment

If your seizures are not completely controlled by the first medication, your doctor may recommend adding a second treatment to use in addition.

The options will depend on your individual circumstances. They include:

• Clobazam.

• Lamotrigine.

• Levetiracetam.

• Perampanel.

• Topiramate.

• Sodium valproate.

Some of these medicines are harmful in pregnancy, and so treatment options may depend on whether or not you are planning to get pregnant in future.

Add-on treatment

If your epilepsy is still not controlled, your doctor may suggest switching your add-on treatment to:

• Brivaracetam.

• Lacosamide.

• Phenobarbitol.

• Primidone.

• Zonisamide.

For information about treatments and prevention, see the separate leaflet called Epilepsy medication and side-effects.

Pour plus d'informations, consultez les brochures séparées intitulées Épilepsie et Types de crises.