Absence seizure — also known as petit mal seizure — involves only a brief, sudden lapse of conscious activity. Occurring most often in children, absence seizure may look like the person is merely staring into space for a few seconds.
Compared with other types of epileptic seizures, the petit mal variety is very mild. But that doesn't mean they can't be dangerous. Children with a history of absence seizure must be supervised carefully while swimming or bathing, because of the danger of drowning. They may also be restricted from driving and other potentially hazardous activities.
Some people experience hundreds of these episodes each day, which interferes with their performance at school or work. Absence seizures can usually be controlled with anti-seizure medications. Many children outgrow these seizures in their teen years.
In most cases, no underlying cause can be found for absence seizures. Some children simply seem to have a genetic predisposition to them. Sometimes flashing lights or hyperventilation can trigger an absence seizure.
When to seek medical advice :
Most of the time, no first aid is necessary for an absence seizure. Contact your doctor if it's the first time you've noticed a seizure or if a new type of seizure occurs. People who have absence seizures can also experience other types of seizures.
Prolonged confusion or automatic behaviors — performing such activities as eating or moving without being aware of it — can be a symptom of a dangerous condition called absence status epilepticus and require immediate medical attention.
Signs of absence seizures include :
- Staring, without unusual movement
- Lip smacking
- Fluttering eyelids
- Hand movements
Absence seizures last only a few seconds. Full recovery is almost instantaneous. Afterward, there is no confusion, but also no memory of the incident.
Absence seizures may occur for weeks or months before an adult notices them, because they're so brief. A noticeable decline in a child's learning ability may be the first sign of this disorder. Teachers also may comment about a child's inability to pay attention.
Some children experience episodes that resemble absence seizures, but aren't truly seizures. This most often occurs in children with mental retardation, autism or attention-deficit/hyperactivity disorder.
Nonepileptic staring spells usually occur when the child is bored or involved in quiet activities such as sitting in class or watching television. These episodes can be interrupted by calling the child's name or by touching his or her shoulder. True absence seizures, on the other hand, cannot be interrupted by voice or touch. They also often occur right in the middle of a child's conversation or physical activity.
For a proper diagnosis, your doctor will ask for a detailed description of your child's seizures. Blood tests can help rule out other potential causes of seizures, such as a chemical imbalance or the presence of toxic substances. Other tests may include:
- Electroencephalography (EEG). This painless procedure measures the waves of electrical activity in the brain. The brain waves are transmitted to the EEG machine via small electrodes attached to the scalp with paste or an elastic cap. Your child may be asked to hyperventilate or look at flickering lights, in an attempt to provoke a seizure.
- Brain scans. Tests such as magnetic resonance imaging (MRI) and computerized tomography (CT) can produce very detailed images of the brain, which can help rule out other types of problems such as a stroke or a brain tumor. These tests aren't painful, but your child will need to hold very still for up to an hour. Most children under five years old are sedated during these tests.
While most children outgrow absence seizures, some people continue to have these types of seizures throughout their lives. In some cases, people who have petit mal seizures eventually begin experiencing full convulsions (grand mal or generalized tonic-clonic seizures).
Other complications can include :
- Learning disabilities
- Absence status epilepticus, a condition in which seizure behavior lasts longer than a few minutes
Many medications can effectively reduce or eliminate the number of petit mal seizures. Finding the right medication and dosage can be complex, requiring a period of trial and error. Taking the medications on a regular schedule is crucial to maintaining the proper drug levels in the blood.
The most effective medications for petit mal seizures include ethosuximide (Zarontin), valproic acid (Depakene) and lamotrigine (Lamictal). Most children can discontinue anti-seizure medications, under a doctor's supervision, after they've been seizure-free for two years.