Absence seizures are brief episodes of blanking out, typically lasting about 10 seconds, where a person suddenly loses awareness and stares into space without falling down. They were previously called “petit mal” seizures. Most commonly affecting children between ages 3 and 8, these seizures can happen dozens of times a day and are often mistaken for daydreaming or inattention.
What Happens During an Absence Seizure
The hallmark of an absence seizure is a sudden stop in activity. A child might freeze mid-sentence, stare blankly for a few seconds, then resume exactly where they left off with no memory of the pause. Most episodes last about 10 seconds, though some stretch to 30 seconds. The person doesn’t fall, doesn’t convulse, and doesn’t appear distressed.
Subtle physical signs often accompany the staring spell: eyelid fluttering, lip smacking, chewing motions, finger rubbing, or small repetitive movements of both hands. These are easy to miss, especially in a busy classroom. Because the episodes are so short and undramatic, children can have hundreds of seizures before anyone notices something is wrong.
What’s Happening in the Brain
Absence seizures originate from abnormal communication between two brain regions: the outer layer of the brain (the cortex) and a deeper relay station called the thalamus. These two areas normally pass signals back and forth in a controlled rhythm. During an absence seizure, a hyperexcitable zone in the cortex drives this loop into a pattern of synchronized firing, where neurons lock into a repetitive cycle of excitation and inhibition. This electrical “short circuit” temporarily overrides normal brain activity, producing the characteristic blank stare and loss of awareness. The seizure stops as abruptly as it starts when the loop breaks out of its synchronized pattern.
Why It Gets Confused With ADHD
Staring spells are one of the most common symptoms of both absence epilepsy and ADHD’s inattentive type, which creates a real diagnostic challenge. A child who repeatedly zones out in class, misses instructions, and seems to lose track of conversations could plausibly have either condition. There’s no blood test or scan that diagnoses ADHD, and even the brain wave test used for epilepsy can sometimes appear normal between seizures.
The key difference is interruptibility. A child who is daydreaming or distracted by ADHD can be snapped out of it by calling their name, touching their shoulder, or making a loud noise. A child in an absence seizure cannot. They are genuinely unconscious for those few seconds and will not respond to any external stimulus until the seizure ends on its own. If a child doesn’t respond to treatment for ADHD, or if their staring episodes have a very abrupt start and stop with no apparent trigger, further evaluation for seizures is worth pursuing.
How Absence Seizures Are Diagnosed
The definitive test is an electroencephalogram (EEG), which records electrical activity across the brain. Absence seizures produce a distinctive pattern: a regular, rhythmic spike-and-wave discharge firing at about 3 cycles per second across the entire brain. This pattern is so characteristic that it essentially confirms the diagnosis. In adolescents, the pattern may be slightly faster and more irregular, running between 3 and 5.5 cycles per second.
Doctors sometimes trigger a seizure during the EEG by asking the child to breathe rapidly (hyperventilate) for a few minutes, which reliably provokes absence seizures in most children who have them. This makes diagnosis relatively straightforward compared to other seizure types.
Types of Absence Seizures
The International League Against Epilepsy recognizes several subtypes. Typical absence seizures are the most common, producing the classic brief stare with possible eyelid fluttering. Atypical absence seizures tend to start and end more gradually, last longer, and produce slower brain wave patterns (under 2.5 cycles per second on EEG). Two rarer forms also exist: myoclonic absence seizures, which involve rhythmic jerking of the arms or shoulders during the episode, and absence seizures with eyelid myoclonia, where pronounced eyelid flickering is the dominant feature.
Treatment
Medication controls absence seizures effectively in most children. A landmark clinical trial compared the three main options head-to-head and found that two of them, ethosuximide and valproic acid, were significantly more effective than the third option, lamotrigine. About 53 to 58 percent of children became seizure-free on either ethosuximide or valproic acid within 16 to 20 weeks, compared to only 29 percent on lamotrigine.
Between the two more effective options, ethosuximide emerged as the better first choice because valproic acid was associated with greater problems with attention and focus, which is the last thing a school-age child with an already-disruptive seizure disorder needs. If ethosuximide alone doesn’t work, doctors typically try combinations or switch medications.
Long-Term Outlook
Many parents hear that children “outgrow” absence seizures, and that’s true for the majority, but the numbers are less reassuring than the phrase implies. A long-term study following children with typical childhood absence epilepsy found that 65 percent eventually achieved full remission. That means about one in three did not. Roughly 15 percent of the original group went on to develop juvenile myoclonic epilepsy, a different seizure disorder that typically persists into adulthood and involves muscle jerks and sometimes full convulsive seizures.
The children most likely to outgrow their seizures tend to be those who responded well to medication early, had a normal neurological exam, and had no other seizure types. Children whose absence seizures began later in childhood or who also experienced convulsive seizures had a higher chance of continuing to need treatment.
Safety and Daily Life
Because absence seizures cause brief lapses in consciousness rather than falls or convulsions, the safety concerns are more subtle but still real. A child who blanks out for 10 seconds while crossing a street, swimming, or riding a bike faces genuine risk. The buddy system is essential for water activities, and a properly fitted life vest should be worn near open water regardless of swimming ability.
Most sports are safe for children with absence seizures, including contact sports like soccer, basketball, and football. The Epilepsy Foundation recommends that children with uncontrolled seizures avoid high-risk activities like rock climbing, scuba diving, and skydiving, where even a momentary loss of awareness could be fatal. For everyday activities like biking, sticking to quiet streets or bike paths and always wearing a helmet are practical precautions.
In the classroom, teachers who understand the condition can make a significant difference. Seating the child near the front, repeating instructions after a suspected episode, and providing written notes to fill gaps in missed information help prevent absence seizures from derailing academic progress. A medical alert bracelet is recommended for any child with active seizures so that unfamiliar adults can respond appropriately.