Electroencephalography (EEG) and Epilepsy

It is a test method which amplified the electrical activity of brain and either print these in paper or on computer media. It is safely used for even pregnant patients.

The test is required for epilepsy diagnosis, epilepsy classification, monitoring the efficiency of epilepsy treatment as well as any kind of alteration in consciousness, which could result from toxic factors.

There 3 32-chanelled (two of which are able to conduct video screening) and 1 10-channelled EEG (with this portable device, screening can be carried out at emergency service and intensive care departments) at the department of Neurology at Hacettepe Adult University, A Floor EEG laboratories, which mainly offer service for outpatients.

5 technicians (Chief technician Ertuğrul Kaplan and his team) work at the EEG laboratory. There is also an Adult Video-EEG Monitorisation Unit located in Ward 31 with 2 beds for inpatient care. This unit comprises of a 64-channelled device capable of conducting polysomnography recording and a 128-channelled device capable of conducting invasive EEG recording. EEGs are evaluated by 1 professor and 1 associate professor specialized in this issue.

Types of Screening

20-30 minutes of routine recording in scope of outpatient care clinic: the patient must come to the screening with a full stomach. The patient lies with his/her eyes closed and screening is conducted for 20-30 minutes. During the screening, a technician requests from the patient to perform deep breathing and to open and close their eyes simultaneously. Photic(light) stimulation is applied at differing frequencies through the end of the screening.

The patient is requested not to sleep during the night in accordance with physician's instructions and 1-3 hours of EEG screening is carried out. The patient is supposed to sleep during the screening. If the screening is carried out on 32-channelled EEG, additional electrodes such as EKG, T1 and T2 are also applied.

In both types of screenings stated above, the electrode stickers are chyle or commercially available ready-to-use stickers. The patient is taken to the hair washing room following the screening, where he/she is provided with hot water, shampoo and a clean towel.

Based upon the physicians demand who is dealing with the epilepsy patients, the patients are transferred to adult video-EEG monitorization unit together with their hospital attendants for video-EEG monitorization. The objective here is to simultaneously record the video images of the attack and the EEG. Here, the electrodes are placed onto the head with a material called collodion, which ensures firm adhesion to the head. Continuous EEG image is recorded while the patient carries out his/her normal daily activities in front of a video camera. The test is needed when the area of the brain which constitutes the source of seizure should be determined,

Collodion sticker is cleaned by the nurse following the screening with acetone. Patients are advised to bring a cream shampoo with them. In addition to that, women are adviced to come for inpatient treatment with pajamas instead of a bedgown.

To conduct video-EEG monitorization with intracranial electrodes, video-EEG monitorization with electrodes sticked on scalp must have been carried out and the situation of the patient must have been discussed at the epilepsy surgery meeting. Electrodes are placed in the head with an operation. Through the recording of crisis via video-EEG monitorization, the exact part of the brain causing the damage is tried to be detected. In addition to that, by means of stimulation works, the relationship between speaking and motor fields and the epileptogenic fields is analysed.

EEG screening during the operation as well as EEG screening during WADA test can also be carried out in our hospital. These tests are applied to the patients selected by the physicians responsible from the Unit.

How to arrange an appointment? When are the results received?
Appointments are generally daily arranged for routine outpatient EEGs. For EEGs with sleep deprivation, it is generally possible to arrange an appointment for the next day. For long digital outpatient EEGs, an appointment for screening might be arranged within a few days. For inpatient treatment at the monitorization unit, the doctor must first examine the patient and include the patient in the waiting list for inpatient treatment. Inpatient treatment might take 6-8 weeks to commence.

The day after the screening, the reports are given to the patient in the afternoon. Monitorization reports are finalized within 1-2 weeks after the patient's discharge.