When children show certain symptoms that make us suspect epilepsy, whether it is muscle stiffness, twitching, jerking, staring blankly, confusion, or becoming unresponsive without realizing it, as well as repeated frequent seizures even if they occur with a high fever, it may be epilepsy.
Diagnosing epilepsy to determine the true cause is very important because it allows for targeted treatment, resulting in effective outcomes. In addition to a detailed medical history and physical examination by the doctor, there are tools that help detect the exact location of abnormalities in the brain that cause seizures. This is the electroencephalogram or EEG.
Various Questions About EEG Brain Wave Testing
- What is a brain wave test?
- Is it scary?
- What are the advantages and disadvantages? And
- At what age can it be performed?
What is an Electroencephalogram or EEG?
Normally, the human brain contains a type of nerve cell called neurons, numbering in the billions, which connect by transmitting electrical particles from one cell to another, stimulated by neurotransmitters, releasing electrically charged particles along nerve fibers, sending signals in a chain called brain waves.
In medicine, we measure the brain’s electrical activity on the scalp and record the electrical signals, which are the sum of electrical currents from groups of brain cells, displayed as graphs on a monitor screen.
EEG testing requires patient preparation before the test. The test is very safe, using only electrodes attached to the scalp skin, with nursing staff providing care throughout the procedure. This brain wave test can even be performed on newborns.
Advantages of EEG Testing
- It can be used to diagnose patients suspected of epilepsy and identify the type of seizures, as well as monitor treatment outcomes. However, in more than 40% of epilepsy cases, EEG results may appear normal because the pathology originates from deep brain areas or the electrical currents are too weak for the machine to record. Therefore, medical history is essential to support the diagnosis and help differentiate types of epilepsy.
- It helps diagnose brain diseases and locate abnormalities in the brain, such as brain tumors, encephalitis, injuries, or brain hemorrhages.
- It indicates the level of brain arousal in patients with altered consciousness, drowsiness, or coma.
The limitation of the test is that it requires cooperation from the children undergoing the test and adequate patient preparation.
When Preparing Your Child for an EEG
- Wash the child’s hair cleanly, preferably one day before the test, and avoid using oils, creams, sprays, or hair mousse.
- Children can eat normally and should not fast, as low blood sugar can cause abnormal EEG changes.
- For patients taking anti-seizure medication, they can continue as usual unless the doctor advises stopping the medication before the EEG, which will be explained to the parents.
- Arrive about 30 minutes before the appointment to prepare for the test.
- For young children, sedation may be necessary before the test. Parents should bring milk bottles, water bottles, and the child’s favorite toys.
- If the child can be kept awake before the test, they may fall asleep during the test without sedation.
EEG Testing Procedure
- The staff will position the patient to lie on a bed or reclined chair.
- Attach electrodes to the cleaned scalp at various positions, then connect the electrodes to the EEG machine.
- Before recording, instruct the patient to close their eyes, relax, and remain still.
- When the machine is turned on, a graph line appears, representing the brain’s electrical signals displayed on the monitor throughout the recording.
- During the test, blinking, swallowing, talking, or other movements are recorded and noted on the tracing, as these movements can cause abnormal lines that may lead to incorrect interpretation.
- After baseline recording, brain wave activity is stimulated by various methods to detect abnormalities more clearly, such as deep and rapid breathing (hyperventilation) for 3-5 minutes, or flashing lights at different frequencies (photo stimulation) directed at the patient’s face, flashing 1-20 times per second, to test the central brain’s response to light.
- After the test, staff will help remove the electrode cream from the patient’s hair.
- The resulting graphs will be analyzed by a specialist doctor to assess the results and plan further treatment.
Asst. Prof. Dr. Chidchanok Thianphat
Specialist in Pediatric Neurology
Child and Adolescent Health Center, Phyathai 2 Hospital
