An EEG (electroencephalogram) is a painless test that records the electrical activity in your child’s brain using small metal discs placed on the scalp. It’s the primary tool doctors use to evaluate seizures, diagnose epilepsy, and investigate unexplained episodes like staring spells or sudden body jerks. The test itself typically takes 30 minutes to an hour, though setup adds extra time.
Why a Doctor Orders an EEG
The most common reason is to evaluate a child who has had a seizure or episodes that might be seizures. An EEG helps the neurologist determine the specific seizure type and whether it fits a recognized epilepsy pattern. This matters because different types of epilepsy respond to different treatments.
In younger children, an EEG can help identify conditions like childhood absence epilepsy, where a child briefly zones out and stares, or infantile spasms, which involve sudden stiffening or jerking movements in babies and are often accompanied by developmental delays. For older children and teens, the test can detect patterns associated with juvenile myoclonic epilepsy or more complex conditions. Doctors also order EEGs when a child has unexplained fainting, unusual movements, or behavioral changes that could have a neurological cause.
What Happens During the Test
A technologist starts by measuring your child’s head and marking spots where each electrode will go. They’ll gently scrub those areas to remove oil from the skin, then use a sticky paste to attach small, flat metal discs. Wires connect each disc to the EEG machine. This setup process takes about 30 minutes. None of it hurts, though the scrubbing can feel mildly scratchy and the paste feels cold and unusual.
Once everything is in place, your child lies still or sits quietly while the machine records brain activity. The recording itself lasts a minimum of 20 minutes, though most sessions run 30 minutes. During this time, the technologist may ask your child to do two specific things designed to provoke abnormal brain activity if your child is susceptible to it.
The first is hyperventilation: breathing deeply and rapidly for three to five minutes. Technicians often give younger kids a balloon or toy windmill to blow on, which makes the breathing feel more like a game. This can trigger absence seizures in children who have them. Your child may feel briefly dizzy or tingly, but that passes quickly once normal breathing resumes. The second is photic stimulation, where a light flashes at increasing speeds in front of your child’s closed eyes in a dimly lit room. This helps detect photosensitive epilepsy.
Types of Pediatric EEG
A routine EEG is the standard version, done during a single office visit. It works well when abnormal brain activity happens frequently enough to show up in a short recording window.
When seizures are infrequent, a doctor may recommend an ambulatory EEG. Your child wears a portable recording unit home for 24, 48, or 72 hours, going about normal daily activities. This significantly increases the chance of capturing an event that a 30-minute test would miss. No hospital stay is required.
A video EEG records brain activity and video simultaneously. This is especially useful when doctors need to see exactly what your child’s body does during an episode and match it to the electrical patterns in the brain at that moment. It helps distinguish epileptic seizures from episodes caused by other things, like stress or heart rhythm irregularities. For children whose seizures don’t respond to medication, video EEG can also pinpoint which part of the brain is generating the seizures, helping doctors decide whether surgery is an option.
Sleep-Deprived EEG
Some brain abnormalities only appear during sleep or when a child is drowsy. For a sleep-deprived EEG, you’ll need to restrict your child’s sleep the night before so they fall asleep naturally during the recording. The guidelines from Children’s Hospital of Philadelphia give a sense of typical requirements: children 8 and older stay up all night (they can sleep until 10 p.m. but must be awake after that), children ages 6 to 7 wake up at 2 a.m., children ages 2 to 5 wake up at 3 a.m., and children under 2 wake up at 5 a.m. One important detail: don’t let your child fall asleep in the car on the way to the appointment, or the sleep deprivation won’t serve its purpose.
How to Prepare Your Child
Wash your child’s hair thoroughly before the appointment and skip any styling products like gel, mousse, or hairspray. Clean, product-free hair helps the electrode paste stick properly. Your child should eat normally and continue taking any prescribed medications unless the neurologist specifically says otherwise. Avoid giving your child anything with caffeine for 24 hours before the test.
For younger kids or children who tend to be anxious, bring comfort items: a favorite stuffed animal, blanket, book, or a tablet loaded with videos. Having something familiar helps them stay calm and still during the recording. Handheld items like small toys or games also keep little hands busy so they’re less tempted to pull at the electrodes.
Accommodations for Sensory-Sensitive Children
If your child has autism, sensory processing differences, or developmental disabilities, the test can feel overwhelming. Good EEG labs have strategies for this. Before the electrodes go on, the technologist may let your child touch the paste and feel the scrubbing material on their hand first. Some children do better when they can place an electrode on a parent’s hand to see that it doesn’t hurt. Picture books showing another child going through each step can also provide reassurance.
Technologists typically apply electrodes to the least sensitive areas of the head first, saving more sensitive spots for last. Letting your child count down sections (“We’re done with the back of your head, now we’ll do the side”) gives them a sense of progress and control. Sticker rewards after each section can help children who need immediate feedback. If your child has visual sensitivities, the technologist can discuss with the doctor whether the flashing light portion is necessary or can be skipped. Let the lab know about your child’s specific needs when you schedule the appointment so they can plan extra time and accommodations.
What the Results Mean
A neurologist reads the EEG by looking at the patterns of electrical waves the brain produced during the recording. Normal brain activity has a recognizable rhythm that changes with age, so pediatric EEGs are interpreted differently than adult ones.
Abnormal results generally fall into two categories. The first is epileptic patterns: brief electrical spikes, sharp waves, or spike-and-wave complexes that indicate a group of neurons is firing abnormally. Where these appear on the recording tells the neurologist which part of the brain is involved. For example, spikes in the central and temporal regions are characteristic of benign childhood epilepsy with centrotemporal spikes, one of the most common and typically outgrown childhood epilepsy syndromes.
The second category is slowing, where brain waves move more slowly than expected. This reflects brain dysfunction rather than epilepsy. Continuous slowing in one area can point to structural problems like a brain injury. Intermittent rhythmic slowing in the back of the head is frequently associated with childhood occipital epilepsy, while similar patterns in other locations can indicate metabolic issues, infections, or other conditions.
A normal EEG doesn’t always rule out epilepsy. The brain may simply not have produced abnormal activity during the recording window, which is why doctors sometimes order longer or repeated studies. An abnormal EEG combined with your child’s symptoms and medical history gives the neurologist the information needed to make a diagnosis and recommend treatment.
After the Test
The electrodes come off quickly, but the paste left in your child’s hair can be stubborn. Most of it washes out with a clarifying shampoo and warm water. A fine-toothed comb helps work out stubborn bits. If regular shampoo doesn’t do the job, a small amount of acetone (nail polish remover) applied carefully can dissolve tougher residue, though it can dry out hair and irritate sensitive scalps. If you’re unsure what type of adhesive was used, call the EEG lab and ask. They often have specific product recommendations. Some parents have also had success asking a hairdresser for help, as some stylists have experience with medical adhesive removal.
Results aren’t typically available the same day. The neurologist needs time to review the full recording, and you’ll usually discuss findings at a follow-up appointment or receive a call within a few days to a week.