The different lobes of the brain are responsible for particular functions, such as language, memory, or speech. Each electrode has a number, and the technician will put the electrodes with odd numbers on the left side of the head and those with even numbers on the right.Įach electrode also has an assigned letter, which will be either F for frontal lobe, P for parietal lobe, O for occipital lobe, T for temporal lobe, or Z for the midline. They will place each electrode either 10% or 20% of the distance between specific points on the head. These patterns help diagnose epilepsy.ĭuring an EEG, the technician will place the electrodes in a particular arrangement called the 10-20 system. If a person has a seizure during an EEG, this interrupts normal brain activity, and the technician can see abnormal brain waves. Share on Pinterest A doctor can help with interpreting EEG results.ĮEG tests demonstrate what is happening in the brain at the time of the test. It is easy to wash the EEG gel out of the hair. If the person has a seizure during the EEG, the technician will respond appropriately to help them.Īfter the procedure, the technician will remove the electrodes, and the person can usually go home unless their doctor advises against it. Sometimes, a doctor will record an EEG on video so that they can compare the electrical signals with what is happening to the body. The technician may ask the individual to perform various commands, such as blinking the eyes, looking at flashing lights, or breathing deeply, because these behaviors might bring on abnormal electrical signals. Doing this helps ensure that the recording will be of high quality.ĭuring the test, the room will be quiet and dark. They will rub a paste called conductive gel between the electrodes and the scalp to make sure that the electrodes receive a strong signal from the brain. The EEG technician will measure the person’s head, and they might use a wax crayon to mark where the electrodes should go. The person will relax in a chair or lie on a bed during the test.

Including the preparation time, the entire test may take 1 to 1.5 hours. The EEG test is not invasive, painful, or harmful, and it has no lasting effects.Īccording to the Epilepsy Foundation, the procedure usually lasts approximately 20 to 40 minutes. This cap contains between 16 and 25 flat metal discs called electrodes, which measure the electrical activity of the brain. During an EEG test, a skilled EEG technician will place an electrode cap on the person’s head.

Eeg epilepsy vs normal