Make an Appointment
Talk to DoctorOverview
Absence seizures, also known as petit mal seizures, are short seizures that cause a lapse in awareness. They typically occur suddenly, without warning, and only last a few seconds. These seizures are common in children and can sometimes be mistaken for daydreaming or inattentiveness. The person quickly recovers after the seizure ends.
Fortunately, absence seizures usually do not result in physical harm. However, there is a risk of injury if the person loses consciousness while engaged in activities like driving a car or riding a bike.
Treatment for absence seizures often involves the use of anti-seizure medications. Some children who experience absence seizures may also develop other types of seizures, such as generalized tonic-clonic seizures or myoclonic seizures. Many children tend to outgrow absence seizures during their teenage years.
Symptoms
A simple absence seizure is characterized by a vacant stare, which can sometimes be mistaken for a momentary lapse in attention. The seizure typically lasts around 10 seconds, but it can extend up to 30 seconds. Following the seizure, there is no confusion, headache, or drowsiness experienced.
The symptoms of absence seizures can manifest as:
- Abrupt cessation of activity (sudden silence and immobility)
- Repetitive lip smacking
- Fluttering of the eyelids
- Chewing movements
- Rubbing of fingers
- Minor movements involving both hands
- Brief episodes of staring or a vacant expression
- Temporary loss of awareness
- Swift resumption of activity once the seizure concludes
After an absence seizure ends, individuals typically resume their activities as if nothing happened. They remain fully awake and capable of clear thinking. In most cases, no first aid is necessary for this type of seizure.
However, when absence seizures occur frequently or multiple times in a day, individuals may exhibit signs of confusion and lose track of recent events. For children attending school, this can result in unawareness of classroom activities, missed instructions from the teacher, or incomplete assignments. If you suspect your child is experiencing seizures, it is important to reach out to their pediatrician. This is particularly necessary if you observe new symptoms or changes in the type of seizures in a child with epilepsy. Additionally, if your child’s seizures persist even after being on anti-seizure medication, it is crucial to contact their pediatrician for further evaluation and guidance.
For prolonged automatic behaviors or confusion lasting minutes to hours, or seizures lasting more than five minutes, contact emergency services immediately.
Causes
Absence seizures are often caused by genetic factors. Seizures, in general, occur when nerve cells in the brain, known as neurons, release bursts of electrical impulses. Neurons communicate through electrical and chemical signals transmitted across synapses. Individuals experiencing seizures have abnormal brain electrical activity. During absence seizures, these abnormal electrical signals occur repeatedly in a three-second cycle. Furthermore, individuals with seizures may have imbalances in neurotransmitters, which are chemical messengers facilitating communication between nerve cells.
Risk factors
Risk factors associated with absence seizures include specific characteristics commonly found in children with this condition, such as:
- Family history: Approximately 25% of children with absence seizures have a family member who also experiences seizures, indicating a genetic predisposition to the condition.
- Age: Absence seizures are more frequently observed in children ranging from 4 to 14 years old. However, absence seizures can also occur in older teenagers and adults.
- Sex: Females have a higher prevalence of absence seizures compared to males.
Diagnosis
When evaluating your child’s seizures, the healthcare provider will probably ask for a detailed description of the episodes. They may also conduct a physical examination. Additionally, to gather more information, the following tests might be performed:
- Electroencephalography (EEG): This non-invasive procedure involves measuring the electrical activity in the brain by placing small metal plates, called electrodes, on the scalp using paste or an elastic cap. During an EEG, your child may be asked to engage in rapid breathing, known as hyperventilation, which can trigger absence seizures. The EEG machine records the brain waves, and any abnormalities in the pattern can indicate a seizure.
- Brain scans: Imaging techniques like MRI (Magnetic Resonance Imaging) can be utilized to eliminate other possible causes of the seizures, such as strokes or brain tumors. These scans provide detailed images of the brain, but they require the child to remain still for extended periods. If necessary, you can discuss with the healthcare provider the potential use of sedation to help your child remain calm during the procedure.
Treatment
The healthcare provider for your child may initially prescribe the lowest dosage of anti-seizure medication available. Depending on the effectiveness in controlling seizures, the provider may gradually increase the dosage as necessary. If the child remains seizure-free for a period of two years, under the supervision of the provider, there is a possibility of gradually reducing and discontinuing the anti-seizure medication.
The medications commonly prescribed for absence seizures are as follows:
- Ethosuximide: This is usually the initial drug of choice for treating absence seizures, and it often yields positive results. Potential side effects may include nausea, vomiting, sleepiness, sleep disturbances, and hyperactivity.
- Valproic acid: Valproic acid is effective for children who experience both absence seizures and tonic-clonic seizures (grand mal seizures). Side effects can include nausea, attention problems, increased appetite, and weight gain. In rare cases, it may lead to inflammation of the pancreas and liver failure. Females who require long-term medication into adulthood should have a discussion with their healthcare providers about the potential risks of valproic acid, as it has been associated with a higher risk of birth defects in babies. Typically, it is advised not to use this medication during pregnancy or when attempting to conceive.
- Lamotrigine: Lamotrigine has been found to have slightly lower efficacy compared to ethosuximide or valproic acid in certain studies. However, one of its notable advantages is that it tends to cause fewer side effects. Common side effects associated with lamotrigine include rash and nausea.
Although a ketogenic diet could be considered, there isn’t enough strong evidence to support its effectiveness. It might be an option to try if your child’s absence seizures don’t improve with medication.
