What Are Absence Seizures?
Epilepsy is a nervous system disorder that causes seizures. Seizures are temporary changes in brain activity. Doctors categorize and treat different types of epilepsy based on the kind of seizure they cause. Absence seizures, or petit mal seizures, are brief, usually less than 15 seconds, and they have symptoms that may be barely noticeable. However, loss of consciousness, even for such a short time, can make absence seizures dangerous.
Absence seizures most commonly affect children from 5 to 9 years old. They can also occur in adults. Children with epilepsy may experience both absence and grand mal seizures. Grand mal seizures last longer and have more intense symptoms.
The signs of an absence seizure include:
- staring off into space
- smacking the lips together
- fluttering eyelids
- stopping speech in the middle of a sentence
- making sudden hand movements
- leaning forward or backward
- appearing suddenly motionless
Adults often mistake children with absence seizures for misbehaving or being inattentive. A child’s teacher is often the first to notice absence seizure symptoms. The child will appear temporarily absent from their body.
You can tell if a person is experiencing an absence seizure because the person is unaware of their surroundings, even with touch or sound. Grand mal seizures may begin with an aura or warning sensation. However, absence seizures typically occur suddenly and with no warning. This makes taking precautions to protect the patient important.
Your brain is a complicated organ, and your body relies on it for many things. It maintains your heartbeat and breathing. The nerve cells in your brain send electrical and chemical signals to each other to communicate. A seizure interferes with this electrical activity in the brain. During an absence seizure, your brain’s electrical signals repeat themselves. A person who has absence seizures may also have altered levels of neurotransmitters. These are the chemical messengers that help cells communicate.
Researchers don’t know the specific cause for absence seizures. The condition may be genetic and able to pass down from generation to generation. Hyperventilation or flashing lights may trigger an absence seizure in others. Doctors may never find a specific cause for some patients.
A neurologist is a doctor who specializes in diagnosing nervous system disorders such as epilepsy. Neurologists evaluate:
- overall health
- pre-existing conditions
- imaging and brain wave scans
Your doctor will try to eliminate other causes of your symptoms before diagnosing absence seizures. They may order an MRI of your brain. This scan captures detailed views of brain vessels and areas where potential tumors could be.
Another way to diagnose the condition uses bright, flickering lights or hyperventilation to trigger a seizure. During this test, an electroencephalography machine measures brain waves to look for any changes to the brain’s functioning.
Anti-seizure medications can treat absence seizures. Finding the right medication involves trial and error and can take time. Your doctor may start with low doses of anti-seizure medications. They may then adjust the dose based on your results.
Some examples of medications used to treat absence seizure are:
- ethosuximide (Zarontin)
- lamotrigine (Lamictal)
- valproic acid (Depakene, Stavzor)
Pregnant women or women who are thinking of becoming pregnant shouldn’t take valproic acid because it increases your risk for birth defects.
Some activities can be dangerous for people with absence seizures. This is because absence seizures cause a temporary loss of awareness. Driving and swimming during an absence seizure might cause an accident or drowning. Your doctor may restrict your activity until they’re certain your seizures are under control. Some states also may have laws about how long a person must go without a seizure before getting back on the road.
Those who have absence seizures may wish to wear a medical identification bracelet. This helps others know what to do in case of an emergency. People also may want to educate loved ones on what to do if a seizure occurs.
Absence seizures typically last between 10 to 15 seconds. The person returns to normal behavior after the seizure. The person usually doesn’t remember the past few moments or the seizure itself. Some absence seizures can last up to 20 seconds.
While absence seizures occur in the brain, they don’t cause brain damage. Absence seizures won’t have any effect on intelligence in most children. Some children may experience learning difficulties because of the lapses in consciousness. Others may think they’re daydreaming or not paying attention.
In most cases, the only long-term effects of an absence seizure occur if the person falls or gets injured. Falls aren’t typical during the seizure. A person can experience absence seizures a dozen or more times per day without any ill effects.
Other people are usually the first to notice absence seizures. This is because the patient is unaware that they’re experiencing a seizure.
Children with absence seizures often outgrow the condition. Absence seizures can continue, however. Some patients progress to longer or more intense seizures.