Adult EEG

An electroencephalography (EEG) measures the electric function of the brain. The examination is performed to clarify the seizure symptoms of the brain’s functional disturbances in particular.

In an EEG, electrodes are attached to the skin on the head with the help of a hat. To achieve excellent electrode contact, gel is applied to the electrodes and some of it may stick to the hair. In addition, clean and dry hair free of hair styling products helps achieve excellent electrode contact.

During the examination, the patient may be shown a flashing light as an activator and asked to breath heavily (hyperventilate) for a few minutes. If it is desirable for the patient to fall asleep during the examination, separate instructions regarding preparations for this will be provided. You should take any medication prescribed to you by your physician according to instructions before the examination.

The examination is painless and harmless.

Children’s sleep EEG

In a sleep EEG or electroencephalogram examination, the electric function of the brain is registered while the patient is awake and asleep. Indications for the examination may include the diagnosis of seizure symptoms or a developmental disorder.

The examination begins by placing a flexible electrode hat or loose electrodes on the child’s head. The skin under the electrodes is scratched lightly and some contact gel is applied to the electrode location to ensure that the brain activities can be properly registered. EEG registration takes place in a recumbent position in bed. In addition to sleep, a state of wakefulness is also registered with the eyes open and closed. Depending on the child’s age, the patient may also be shown a flashing light or asked to breath heavily (hyperventilate) for a few minutes. The examination takes 1–2 hours and it is painless and harmless.

A sleep EEG needs preparations before the examination. Before the examination, the child should eat and drink normally and take any medication that is in regular use. To achieve sound electrode contact, the hair should be clean and dry. In accordance with separate instructions, the duration of the child’s sleep during the previous night is shortened by a few hours to facilitate falling asleep in the examination. In addition to keeping the child awake the previous night, he or she can also be administered melatonin orally during the examination to help them to fall asleep. It is particularly important that the child who has been forced to stay awake does not fall asleep on the way to the examination. All children must have someone accompanying them and this person can stay with the child for the duration of the entire examination. In order for the child to fall asleep during the examination, other children in the family may not be present in the examination room.

The examination is most successful when the child is calm and relaxed. Before the examination, the child can be shown a short video intended for children regarding the sleep EEG registration.