What Does Childhood Absence Epilepsy Look Like?

Childhood absence epilepsy (CAE) is a type of epilepsy characterized by a sudden, brief impairment of consciousness in children. These seizures, known as absence seizures, cause children to stare vacantly.

Once the seizure is over, after around ten seconds, normal consciousness will resume. Approximately 10%¹ of these seizures last longer than 20 seconds. 

Generally, childhood absence epilepsy presents as early as four years of age and as late as eight years. It has an incidence rate of around 8 per 100,000 in healthy school-aged children. For most children, seizures spontaneously cease during their teenage years. 

The brain during a seizure

Normally, your brain sends electrical and chemical messages across synapses — communicating from one neuron to the next. This process usually occurs seamlessly in the background over a millisecond time frame.

When recorded in an electroencephalogram (EEG), which measures electrical activity in the brain, these look like regular waves with a frequency of around eight hertz. 

In seizures, this normal flow of activity is disrupted and replaced with two to four Hz spike-wave discharges (SWDs).² In simple terms, this means abnormal electrical activity in the brain.  

What causes absence seizures? 

Currently, the cause of childhood absence seizures is unknown. CAE is more common in girls, comprising around two-thirds³ of cases. There is a strong genetic link, according to the epilepsy foundation. Around one in three children⁴ with the absence, of epilepsy has a family history of a similar condition.  

While the overall cause of absence seizures is thought to be largely genetic, the exact mechanism by which this occurs is unknown. There are multiple genetic factors at play.

Currently, two mutations have been identified in CAE, affecting GABA signaling and calcium channels in the brain, which affects signals traveling between synapses.

What do absence seizures look like?  

Childhood absence seizures can present subtly. It may look like your child is staring off into space for a few seconds with a blank expression. They will stop all activity and be unresponsive during the seizure.

Afterward, they won’t recall the event and will continue as they were before the seizure. The seizures can happen as often as 10-30 times per day. 

Other possible symptoms of CAE include: 

• Lip smacking

• Chewing motions

• Finger rubbing

• Eyelid flutters

• Small movements of both hands 

Diagnosis

Patient history 

Taking a comprehensive history is the first step in diagnosing CAE — this will identify if your child has had difficulties in learning or experienced repeated staring spells. Providing a diary with the times they occurred and details of what the child was doing during the episode is very helpful for the doctor. Videos of the seizure episodes are, similarly, very useful. 

Electroencephalogram (EEG) test 

Your doctor will record the electrical activity of your child’s brain. This is a well-tolerated test and is not invasive. Through this, they will try to identify abnormalities that could indicate the absence of seizures. The doctor may ask your child to hyperventilate, as this triggers absence seizures in most children with CAE. 

Treatment

Typically, doctors administer medication to treat absent seizures. In most cases, seizures are easy to treat and respond well to medication. 

Ethosuximide 

Ethosuximide is effective at treating around 70% of cases and is generally the first medication prescribed. It acts on calcium channels in the brain, affecting the region that generates the spike and wave discharges, the hallmark of epilepsy.   

Valproic acid

This medication controls seizures in 75% of patients. It may take 1-2 weeks before its effects become noticeable. 

Lamotrigine 

Lamotrigine helps to stabilize the electrical activity of the brain, preventing seizures from occurring. 

A combination of these three medications may be administered in more resistant cases of seizures. In cases where medication isn’t working, doctors may recommend a ketogenic diet⁵ for your child. 

In most children, absence seizures go away by the time they reach their teenage years, and medications are no longer required. In some cases, children may go on to develop generalized tonic-clonic seizures and may require additional long-term treatment. 

Comorbidities

When it comes to any diagnosis, it’s important to recognize that many areas of your life may be affected. Some research⁶ has identified that children diagnosed with CAE are at increased risk of having subtle cognitive deficits, psychiatric diagnoses, and language difficulties. 

Many of these comorbidities are left undiagnosed and untreated. Research has shown that the severity of these associated conditions can be related to their antiepileptic drug treatment, highlighting the need for early identification and treatment of CAE. 

The lowdown

Absence seizures can cause some learning difficulties, or they may cause your child to feel socially isolated. Following a diagnosis, it’s important to engage with their teachers to optimize their learning environment and ensure they’re still able to maximize their learning opportunities. 

Encouraging your child to talk about epilepsy and share their knowledge with others is a great way to boost their confidence and decrease the stigma around epilepsy. Finding a treatment that works is the best first step towards minimizing the impacts of absence seizures so that your child can fully participate in any activities they want to.