Absence Seizure Basics

EEG
Absence Seizures. PHANIE / Getty Images

An absence seizure, also referred to as petit mal seizure, is a type of seizure that is characterized by a sudden and short seizure that can last between 10 and 30 seconds. During this time period, a person suffering from an absence seizure has impaired consciousness, which means that they are not aware of their surroundings or their movements during this time. After the seizure has occurred, the person will abruptly resume consciousness.

An absence seizure is usually is characterized by the following:

  • Rapid blinking of the eyes.
  • Spells where the person appears to be staring out into space.
  • Automatisms or purposeless movements, such as finger tapping or lip smacking.

This type of seizure can happen several times a day and the person may or may not be aware of his or her seizure. If you observe someone having an absence seizure, they may appear as though they are not paying attention to you. However, although they may look harmless, these seizures can impair learning and affect work, due to the bits of time missed during each seizure.

What Causes an Absence Seizure?

Absence seizures are usually first noticed among children ages 4 to 8 – but it can also begin as late as early adolescence. Absence seizures usually have a genetic component to them. Some people who have absence seizures may have a family history of epilepsy. Additionally, some anti-epileptic medications, such as phenytoin (Dilantin) and carbamazepine (Tegretol), also may lead to absence seizures.

In people who are predisposed to absence seizures, hyperventilation can be a trigger.

How Is an Absence Seizure Diagnosed?

Your healthcare provider will take a careful medical history, including the characteristics of the seizures you are experiencing. The biggest clue of a "typical absence seizure" is the presence of a symmetrical generalized 3 Hz spike and wave discharge on the electroencephalogram (EEG).

Which Medications Can Be Used to Treat Absence Seizures?

There are a few anticonvulsant medications that your healthcare provider can place you on to help control your absence seizures, including:

  • Ethosuximide (Zarontin)
  • Valproic acid (Depakene)
  • Lamotrigine (Lamictal)

Your healthcare provider will follow you on a regular basis in order to make sure that you are responding to medication and that no further complications occur. Based on your progress, your healthcare provider may decide to increase your dose.

Source:

Braunwald E, Fauci ES, et al. Harrison’s Principles of Internal Medicine. 16th ed. 2005.

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