Brain Wave Assessment EEG – QEEG

What is an EEG test? An electroencephalogram (EEG) is a noninvasive test that records electrical patterns in the brain.

This test is used to help diagnose conditions such as seizures, epilepsy, head injuries, dizziness, headaches, brain tumors, and sleep problems.

This test is also used to confirm brain death.

How does an EEG work?

Billions of nerve cells in the brain produce tiny electrical signals that create patterns called brain waves.

During an EEG test, small electrodes and wires are attached to the head.

The electrodes detect brain waves, and the EEG machine amplifies the signals and records them as a wave pattern on graph paper or a computer screen.

What is a QEEG (Quantitative EEG)?

Quantitative electroencephalography (QEEG) is a diagnostic tool that measures the amount of electrical activity in different parts of the brain using EEG processing. Using QEEG, it is possible to examine brain function and determine which areas of the brain have increased or decreased electrical activity, thereby revealing weaknesses and strengths and brain problems (disorders). Disorders such as AD/HD, anxiety, depression, Alzheimer’s, learning disabilities, obsessive-compulsive disorder … can be diagnosed using QEEG. To obtain QEEG, first, up to 19 channels of EEG or EEG are taken from the person by placing an EEG cap on the head. In the next step, a series of complex mathematical operations (such as Fourier and wavelet transforms) are performed on the EEG.

The result of these processes is converted into a series of images (colored heads) that we call QEEG or brain map. In fact, a brain map is a method by which we can translate the language of the brain. In a brain map, each colored head corresponds to the activity of a brain wave. The way these waves work together makes us function properly or improperly. If any of the waves are functioning properly, we see the head in green. High brain wave activity is seen in red and low activity in blue. In other brain imaging methods such as CT, MRI, PET, factors such as cerebral blood flow, metabolism or structural integrity of the brain are measured, while as mentioned, QEEG is a tool that measures the amount of electrical activity of the brain.

Interpreting the brain map or QEEG

Today, abnormalities in brain function can be identified by comparing the QEEG of a patient with the QEEG of normal people (available in QEEG analysis databases of normal or normal people) and by matching it with existing patterns, the type of disorder can be determined. The basis for such a comparison is that various psychiatric illnesses cause significant abnormalities in the brain and produce changes in QEEG (Chabet et al., 1999, 2001). Since the spectral composition of the brain’s electrical activity changes with age, when comparing with the normal population, the age of the individual and the normal population should be the same.