Absence Seizures (Petit Mal Seizures)
What Is It?
The brain’s nerve cells (neurons) communicate with one another by firing tiny electric signals. When someone suffers a seizure, the firing pattern of the brain’s electric signals suddenly becomes abnormal and unusually intense. This seizure can affect only an isolated area of the brain, or it can involve the whole brain. If the whole brain is involved, the electrical disturbance is called a generalized seizure. The two most common forms of generalized seizures are tonic-clonic seizures (often called grand mal seizures) and absence seizures (also called petit mal seizures). Although both forms of generalized seizures cause the patient to lose consciousness temporarily, only the grand mal form produces symptoms of a true convulsion, in which the person stiffens falls to the ground, with clenching of the teeth and rhythmic muscle contractions that may last two minutes or longer.
Unlike a grand mal seizure, an absence seizure causes a loss of consciousness that is usually 30 seconds or less, and is barely noticeable. Rather than falling down, the person simply stops moving or speaking, stares straight ahead blankly and does not respond to questions. When the seizure ends, the person resumes normal activities without realizing that anything has happened and has no memory of the seizure. Because most patients who suffer from absence seizures are children, a teacher may be the first to notice this problem.
Epilepsy is defined as a brain disorder that causes recurring seizures. Therefore, a child with repeated absence seizures is said to have childhood absence epilepsy or petit mal epilepsy. Although absence epilepsy can begin at any time during childhood, it is most common in children between the ages of 5 and 15 years. Girls have absence epilepsy more often than boys, and in most cases the reason for the seizures is unknown. Although research suggests that genetic (inherited) factors may play some role in the development of absence epilepsy, there is no practical way to use this information to diagnose the disorder or to screen for it.
During an absence seizure, a child is mentally absent from the surroundings — temporarily unaware of what is happening around him or her. For a few brief seconds, the child stops what he or she is doing, stares straight ahead, and does not respond to an adult’s command to pay attention or wake up. While the seizure is happening, the child’s eyelids may blink or flicker rapidly or an arm or leg may twitch, jerk or move without purpose. After the seizure ends, the child has no memory of the episode and usually resumes previous activities as if nothing happened.
Because a child with absence epilepsy can have many brief seizures during a school day, the disorder may interfere seriously with the ability to pay attention and participate in class. For this reason, a teacher may be the first adult to notice that something is wrong. If the teacher is not familiar with absence seizures, he or she simply may complain that the child is not paying attention, looks out of it or appears to be daydreaming.
Outside the classroom, the child’s symptoms may affect the ability to concentrate when he or she plays sports or does homework. Seizures also may interrupt conversations with friends or family members.
The doctor will begin by asking you to describe your child’s symptoms, including how often the symptoms occur and how long they last. The doctor also will review your child’s medical history, especially any history of birth trauma, serious Head injury or infections involving the brain, such as encephalitis or meningitis. The doctor also will ask whether any other members of your family have had similar symptoms or have received treatment for any type of epilepsy.
The doctor then will perform a thorough physical and neurological examination of your child. This examination may be followed by routine blood tests to check for common medical illnesses that either can mimic epilepsy or trigger seizures. In most cases, the results of your child’s physical examination and blood tests will be normal.
As a final step in the diagnostic process, your doctor may order an electroencephalogram (EEG). An EEG is a painless test that detects the electrical activity in your child’s brain and translates it into a series of printed patterns. In many children with absence epilepsy, the EEG shows a specific combination of spike and wave patterns that confirms the diagnosis. In some cases, the doctor also may order an MRI ( magnetic resonance imaging) or computed tomography (CT) scan of your child’s brain to look for a tumor or other abnormality. This may be done if your child has one or more of the following problems: prolonged seizures, an unusual pattern of symptoms, or abnormal findings on the physical or neurological examination, or if he or she has had a condition, such as birth trauma, Head injury, encephalitis or meningitis), that would put him or her at higher risk of absence seizures.
Most children outgrow absence epilepsy, usually by the time they are teenagers. Before then, anti-epilepsy medication is used to control the symptoms.
Absence epilepsy cannot be prevented because most cases have no known cause.
If your child has absence epilepsy, the doctor will treat the condition with medication, such as ethosuximide (Zarontin), lamotrigine (Lamictal) or valproic acid (Depakene, Depakote). The purpose of these medications is to control the number of seizures your child has, so he or she can reach full potential at school and home. Once your child begins taking a seizure medicine, treatment usually continues for at least two years.
When To Call A Professional
Call your pediatrician or family practitioner if you notice that your child has staring spells, brief periods of deep daydreaming or other behaviors that may be symptoms of absence seizures.
If your child’s teacher complains that your child is not paying attention, tunes out or always daydreams, ask the teacher whether your child shows other symptoms of absence seizures. For example, does your child stare straight ahead at the chalkboard, blink repeatedly or twitch while daydreaming? Request that the teacher write down a detailed description of your child’s symptoms, including an estimate of how long each episode lasts and the number of episodes per day. Once you have this description, check to see whether you notice any of these same behaviors when your child is at home. Then call your doctor to discuss the situation.
The prognosis is very good. Most children with absence epilepsy eventually outgrow the condition without complications. With proper treatment, the child can have a normal life at school and at home. In most cases, there is no long-term effect on brain development, brain function or intelligence.
Diseases and Conditions Center
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.