Understanding Tonic-Clonic Seizure

Talk about seizure and the first idea that will come to mind is an epileptic seizure that involves the entire body. Combine this with drooling, loss of consciousness and violent muscle contractions and you'll get a complete picture of tonic-clonic seizure, or grand mal as it was known a few years ago.

Seizure comes in many forms. It may be a period of inactivity or lapse in consciousness, which is called absence seizure, or seizure of a particular area of the body, which is called partial seizure. But the seizure that most of us are familiar with is the one that affects the entire body. This is called tonic-clonic seizure whose symptoms include a brief warning period called aura, ictal stage or occurrence of the seizure itself, and the period when the brain recovers from the episode called post-ictal period.

It could strike anyone at any age and may happen once over a lifetime or repeatedly, in which case it is called epilepsy.

Tonic-clonic seizure is caused by abnormalities in the electrical activities of the brain in different locations. Such abnormalities involve large areas of the brain, often affecting both hemispheres. Because significant areas of the brain are affected, consciousness and motor movement dysfunctions occur.

This type of seizure can be primary or secondary. Primary tonic-clonic seizures start out as electrical discharges in large areas of the brain as a result of a localized injury or inflammation. Secondary seizure, on the other hand, begins in one particular area of the brain and spreads throughout nearby parts. The two sub-types are differentiated by the presence of aura in the secondary tonic-clonic seizure.

The majority of seizures have no identifiable causes, about 70% of all cases. The rest are caused by a number of things that can range from low glucose level of the blood to severe injury to the brain.

- When there is no identifiable cause, the seizure is called idiopathic. This is usually associated with seizures that occur among patients age 5 to 20. Perhaps the best explanation for idiopathic seizure is that it runs in the family. It turns out, patients who have experienced an episode of seizure between this period have family history of epilepsy and seizure.

- Congenital defects as well as neonatal injuries are also associated with elevated risk of experiencing seizure during the early stages of life up to adulthood.

- In about half of all seizure children patients, the main cause is a fever. In this case, the seizure is called febrile seizure which may accompany such conditions as chickenpox, infection, and even simple cold.

- Tonic-clonic seizure across all age brackets may be a result of the disruption of widespread systemic processes such as severe metabolic problems. It can also be a result of abrupt withdrawal from the use of addictive chemical substances like alcohol, recreational drugs, and even some prescription drugs.

- Abnormal formations like tumors and trauma to the brain which ends up in brain injury and brain lesions can also cause the electrical signals in the brain to go awry.