Absence seizure — also known as petit mal seizure — involves a brief, sudden lapse of conscious activity. Occurring most often in children, an absence seizure may look like the person is merely staring into space for a few seconds.
Compared with other types of epileptic seizures, absence seizures appear 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. Teens and adults may also be restricted from driving and other potentially hazardous activities.
Absence seizures can usually be controlled with anti-seizure medications. Many children outgrow absence seizures in their teen years, though some may eventually develop grand mal seizures.
Signs of absence seizures include:
Absence seizures last only a few seconds. Full recovery is almost instantaneous. Afterward, there is no confusion, but also no memory of the incident. Some people experience hundreds of these episodes each day, which interferes with their performance at school or work.
Children who are walking or doing other complex tasks during a seizure probably won't fall, though they'll be unaware.
Absence seizures may occur for some time 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.
When to see a doctor
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.
Seek immediate medical attention if you observe automatic behaviors — performing such activities as eating or moving without being aware of it — or prolonged confusion. These can be a symptom of a dangerous condition called absence status epilepticus. Additionally, any seizure lasting more than five minutes requires immediate medical attention.
Often, no underlying cause can be found for absence seizures. Many children appear to have a genetic predisposition to them. Sometimes hyperventilation can trigger an absence seizure.
In general, seizures are caused by abnormal nerve cell (neuron) activity in the brain. The brain's nerve cells normally communicate with each other by sending electrical and chemical signals across the synapses that connect the cells. In people who have seizures, the brain's usual electrical activity is altered. During an absence seizure, these electrical signals repeat themselves over and over in a three-second pattern.
People who have seizures may also have altered levels of neurotransmitters, which are the chemical messengers that help the nerve cells communicate with one another.
This type of seizure may be more prevalent in children because there are more synapses in a growing brain. Many children gradually outgrow absence seizures over months to years.
While most children outgrow absence seizures, some people continue to have these types of seizures throughout their lives. In some cases, people who have absence seizures eventually begin experiencing full convulsions (grand mal or generalized tonic-clonic seizures).
Other complications can include:
You're likely to start by first seeing your family doctor or a general practitioner. However, you or your child will probably be referred to a doctor who specializes in nervous system disorders (neurologist).
Because appointments can be brief, and there's often a lot of ground to cover, it's a good idea to be well prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.
What you can do
Your time with your doctor is limited, so preparing a list of questions ahead of time will help you make the most of your time together. List your questions from most important to least important in case time runs out. For absence seizure, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:
Some children experience episodes that resemble absence seizures, but aren't truly seizures. Such episodes can usually be interrupted by calling the child's name or by touching his or her shoulder. True absence seizures, on the other hand, can't be interrupted by voice or touch. They also tend to 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 the 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:
Many medications can effectively reduce or eliminate the number of absence 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.
Often, the first drug prescribed for absence seizures is ethosuximide (Zarontin). However, other medications, such as valproic acid (Depakene) and lamotrigine (Lamictal), also are effective at controlling seizures. Your doctor will likely start at the lowest dose of medication possible, and increase the dosage as needed to control the seizures. Most children can discontinue anti-seizure medications, under a doctor's supervision, after they've been seizure-free for two years.
Female adults who need treatment for absence seizures are advised against using valproic acid while trying to conceive or during pregnancy, because the drug has been associated with higher risk of serious complications for the baby. Women who can't achieve seizure control on any other medication need to speak with their doctors about the potential risks.
A person with absence seizures may elect to wear a medical bracelet for identification for emergency medical reasons. The bracelet should state whom to contact in an emergency and what medications you use. It's also a good idea to let teachers, coaches and child care workers know about the seizures and tell them what to do in an emergency.
Even after they're under control, seizures can continue to affect your life. Children may get teased or be embarrassed by their condition, and both children and adults may be frustrated by living with the constant threat of another seizure. Most states restrict those who've had seizures from driving until they've gone a long time without a seizure. Even recreational activities can be affected, because you can't do certain activities, such as swimming, alone.
You may find it helpful to talk with other people who are in the same situation you are. Besides offering support, they may also have advice or tips for coping that you'd never considered. The Epilepsy Foundation has a network of support groups, as well as online forums for teens and adults who have seizures, and parents of children who have seizures. You can reach them at 800-332-1000 or visit its Web site. You can also ask your doctor if he or she knows of any support groups in your area.