To use all functions of this page, please activate cookies in your browser.
With an accout for my.bionity.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
- My watch list
- My saved searches
- My saved topics
- My newsletter
Tonic-clonic seizures (also known as Grand Mal Seizures, though this term is now discouraged and rarely used in a clinical setting) are a type of generalised seizure affecting the whole brain. Tonic-clonic seizures are the seizure type most commonly associated with epilepsy and seizures in general, though it is a misconception that they are the only type. (See seizure types)
Tonic-clonic seizures are induced deliberately in Electroconvulsive Therapy.
Additional recommended knowledge
The vast majority of generalised seizures are idiopathic.  However, some generalised seizures start as a smaller seizure such as a simple partial seizure or a complex partial seizure and then spread to both hemispheres of the brain. This is called a secondary generalisation.  In the case of idiopathic epilepsy, it is not certain what is the cause of the seizures. However, it is believed that factors could include chemical and neurotransmitter imbalances, and a genetically determined seizure threshold, which have both been implicated. The seizure threshold can be altered by fatigue, malnutrition, lack of sleep or rest, hypertension, stress, diabetes, the presence of neon or laser flashes or lights, rapid motion or flight, blood sugar imbalances, anxiety and other factors. 
In the case of symptomatic epilepsy, it is often determined by MRI or other neuroimaging techniques that there is some degree of damage to a large number of neurons. The lesions (scar tissue) caused by the loss of these neurons can result in groups of neurons episodically firing abnormally, creating a seizure.
Many people who experience tonic-clonic seizures will be aware of an oncoming seizure for up to several minutes before the full seizure begins. This is called an aura and is typically a simple partial seizure or a complex partial seizure which has spread to the whole brain. However, many people who have epilepsy do not experience auras. If a person reports they believe they are about to have a seizure, their safety should be ensured. This can be done by laying them into the recovery position, and removing any objects which may pose a danger to the person during the seizure. If the person does not experience an aura, and goes directly into a seizure, they should be gently eased to the ground if possible.
Once the convulsions have begun, the seizure must simply run its course. No attempt to restrain the person should be made because this risks injury to either party, instead it should be ensured that they do not injure themselves by placing something soft under their head, and ensuring their limbs and body don't bump into walls or other objects. If the person vomits, the person's head should be placed to the side to allow the vomit to run out of the mouth without blocking the airway. Nothing should ever be placed into the person's mouth, as this can cause the person to bite their tongue or choke, (or injure the one placing the object into their mouth). Despite popular belief, it is not possible for someone having a seizure to swallow their tongue. The frenulum of the tongue prevents this.
Once the seizure ends, the person will stop convulsing, the limbs will go limp, and the person will be completely unconscious for a while. Once they start to come to, they will usually be tired, disoriented, and unaware they have had a seizure. A person having a seizure should never be left unattended until they are fully recovered.
If the person is known to have epilepsy, it is not usually necessary to call an ambulance. However, if the person is not known to have epilepsy, the seizure lasts four to five minutes or longer, the person has a second seizure before regaining consciousness, or the person injures themselves or stops breathing (apnea) during or after the seizure, medical attention is needed.
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Tonic-clonic_seizure". A list of authors is available in Wikipedia.|