An electroencephalogram, commonly known as an EEG, is a non-invasive test that records the electrical activity within the brain. The resulting data is recorded as wavy lines that provide a visual representation of brain function. This safe and painless procedure offers doctors an important look into how a child’s brain is working.
What an EEG Measures and Why It Is Used in Children
The EEG measures brain waves, which are rhythmic electrical impulses. These patterns are categorized into different frequency bands, such as delta, theta, alpha, and beta. A specialist analyzes their presence, location, and amplitude to understand the child’s brain function.
A primary reason a child might undergo an EEG is to diagnose or monitor epilepsy and other seizure disorders. Seizures are caused by sudden, abnormal bursts of electrical activity, and the EEG can capture distinct patterns, such as “spikes” or “sharp waves,” that are characteristic of epileptiform activity, even between clinical events. This information is crucial for confirming a diagnosis and classifying the specific type of epilepsy, which then guides treatment decisions.
Beyond seizure disorders, an EEG is also used to investigate a range of other neurological concerns in children. It can be part of the evaluation for unexplained changes in consciousness, such as fainting spells or episodes of confusion. The test may also be ordered when a child exhibits developmental delays, certain learning problems, or significant behavioral changes to assess for underlying neurological causes. Furthermore, the EEG can help identify and classify various sleep disorders by recording brain activity during different stages of sleep.
Essential Preparation Steps for the Child
Parents should ensure their child’s hair is clean and completely dry on the day of the test, having washed it thoroughly the night before or the morning of the appointment. Avoid using any hair products, such as oils, conditioners, gels, or sprays, as these can interfere with the connection between the scalp and the electrodes.
If the doctor has requested a sleep-deprived EEG, specific instructions regarding the child’s sleep schedule must be followed precisely. This protocol is designed to ensure the child falls asleep during the test, as some abnormal brain activity is only detectable in states of drowsiness or sleep. Parents should also ensure their child eats a meal or snack before the appointment, as low blood sugar can affect the brain’s electrical activity.
Avoid giving the child caffeinated beverages or high-sugar foods for several hours before the procedure, as these stimulants can make it difficult for the child to relax or fall asleep. Before the appointment, parents can help alleviate anxiety by explaining the test in simple, reassuring terms, emphasizing that the procedure is painless. Bringing a favorite comfort item, like a blanket or small toy, can also help the child remain calm during the process.
What Happens During the Procedure
The EEG is typically performed in a quiet, comfortable room by a trained technologist who specializes in pediatric procedures. The technologist will first measure the child’s head and mark specific locations on the scalp with a washable crayon or pencil. These marks ensure the small metal discs, known as electrodes, are placed in precise positions according to a standardized system.
The technologist will then lightly rub each marked area with a mild abrasive gel before attaching the electrodes with a special conductive paste or glue. Approximately 16 to 32 electrodes are connected by thin wires to the EEG machine, which amplifies and records the brain’s electrical signals onto a computer. While the setup process may take around 30 minutes, the child can usually sit in a comfortable chair or on a parent’s lap and may be distracted with a movie or toy.
Once the electrodes are secured, the recording session usually lasts between 20 and 45 minutes. The child is asked to remain as still and quiet as possible to minimize movement artifacts in the recording. To activate or provoke certain brain wave patterns, the technologist may ask older children to perform specific tasks, such as opening and closing their eyes. Two common activation procedures are hyperventilation, where the child breathes deeply and rapidly for a few minutes, and photic stimulation, which involves looking at a controlled flashing light.
Understanding the Results and Next Steps
The recorded EEG data is reviewed by a neurologist. The neurologist analyzes the tracing for both the background electrical activity and any transient events, such as abnormal spikes or slow waves. Normal results show symmetrical brain wave patterns that are appropriate for the child’s age and state of alertness.
An abnormal result may show evidence of epileptiform discharges or a general slowing of the background rhythm, which may indicate other types of brain dysfunction. Interpreting the pediatric EEG is complex because a child’s normal brain wave patterns change significantly as they develop, requiring the specialist to compare the findings to age-specific norms. The neurologist will compile a detailed report, which is then sent to the referring doctor.
Parents can generally expect to receive the formal results at a follow-up appointment with the prescribing physician, which may take up to a week or more depending on the facility. If the EEG is abnormal, the next steps often involve a discussion of a treatment plan, which may include medication management or further diagnostic testing. The physician will use the detailed EEG findings, combined with the child’s clinical symptoms and medical history, to determine the most appropriate course of action.