Absence seizures are brief episodes of staring. “Absence” is pronounced ab-SAWNTZ. Another name for this type of seizure is petit mal (PET-ee mahl).

Absence seizures are very brief, and during them, awareness and responsiveness are impaired. People who have them usually don't realize when they've had one. There is no warning before a seizure, and the person is completely alert immediately afterward. They typically last less than 10 seconds, often less than 5 seconds.

Simple absence seizures only cause staring. Complex absence seizures also include a change in muscle activity. The most common movements are eye blinks. Other movements include slight chewing movements of the mouth, hand movements such as rubbing the fingers together, and contraction or relaxation of the muscles. Complex absence seizures are often more than 10 seconds.

Absence seizures can resemble some complex partial seizures or even daydreaming. Here are ways to tell absence seizures from daydreaming:

The most accurate way to diagnose absence seizures is with an EEG (electroencephalogram). Having the child breathe very rapidly often will produce an absence seizure. Images of the brain such as CT and MRI scans are usually normal in patients whose only seizure type is absence.

• Absence Seizures

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Topic Editor: Steven C. Schachter, MD and Patricia O. Shafer, RN, MN.
Last Reviewed:5/25/07