QEEG feature Image

What is a quantitative electroencephalogram (QEEG)?

Quantitative electroencephalography (QEEG) is a scientific, non-invasive way of measuring the relative electrical activity of a person’s brain. In simple terms it is a “Brain Map” showing areas of the brain where there is too much or too little activity or even how different areas of the brain are communicating with each other.

How is the test done?

A QEEG test is very simple and non-invasive. To start a technician places a cap (similar to a swimming cap) on your head, this has points or holes that show the areas where the sensors are to be located. The sensors are placed in up to 30 locations on your scalp and usually on your earlobes. They are attached using conductive a paste or gel that is easily washed off with warm soapy water after the data recording and secured using medical tape. The sensors are then connected to specialised medical equipment that captures the electrical signals your brain produces and sends these signals to a computer which records them for comprehensive and detailed analysis.
Don’t worry about being shocked by your sensors, the only electricity involved in the test is minute amounts of electrical activity from your brain, no electricity comes from the testing unit.

Once we are ready to begin the test, you will be asked to sit quietly for a few minutes with your eye open while the computer collects a sample of brain wave activity. While we are recording your data it is very important to sit as still as possible and try not to move your head, blink as little as possible, and do not to clench your jaw muscles. We will record for about 3 minutes and then repeat this process with your eyes closed. The entire test usually takes around an hour.

After the recording is made it is sent away for reporting (just like when you have an x-ray). Your data is compared by a computer programme against a very large reference database of other people’s data. (A computer is capable of recognizing many more and subtle patterns among the brain waves in various locations than the eye can normally see). Then a report is generated that identifies and highlights variations from what is considered normal or average, according to a person’s age, medical history and even if the person is left or right handed. The report also contains an explanation of findings, detailed information and images of the brain which can show precisely which areas of the brain are not working as well, or communicating as well, as they should.
To see an example of a report, please click the link below.

Reliability of QEEG

QEEG technology has been around since the late 1970’s and extensive research has found QEEG tests have a high level of reliability. QEEG test results are equal or superior in their accuracy when compared to other routinely used clinical tests such as mammograms, blood tests, MRI and CT scans.

QEEG is different to other tests

MRI and CT scans can take pictures of your brain and its structure and are very helpful in assisting in the diagnosis of structural issues within the brain, for example a tumour or stroke, but they provide limited information on how the brain is actually functioning. This is why a QEEG is important, it provides us with very precise and detailed results about how your brain is functioning.

QEEG is helpful in the diagnosis a wide range of brain disorders

QEEG is particularly useful in evaluating difficult cases and can be helpful in diagnosis of many problems including but certainly not limited to:
Anxiety and panic disorders, balance problems, developmental delay and dyspraxia, ADHD, Autism, Asperger’s, learning difficulties, memory problems, brain injury and stroke, Chronic Fatigue Syndrome (CFS/ME), chronic pain, dizziness and vertigo, Fibromyalgia, migraines, and sleep disorders (such as snoring, sleep aponea and insomnia).

What Can a QEEG Tell You About Your Brain?

A QEEG will give you information on a number of aspects of your brain wave functioning:

1) Absolute and relative power: shows the balance of activity in each brain wave band and compares each band against the others. There are 4 types of brain waves beta, alpha, theta and delta. When there is more or less activity in one or more of the areas, it can indicate you brain is not working at its best. For example, it has been shown that people with ADHD often have too much theta activity compared to their beta activity when their eyes are open. What this may show is their brains are producing an excess of waves associated with internal focus and drowsiness (theta) and not enough of the waves associated with external focus and alertness (beta).

2) Coherence: measures how much electrical activity or communication is happening between different parts of your brain. High coherence or communication between two locations means they are sharing too much. Low coherence means the two sites are not sharing enough. Both indicate the brain is not using its resources efficiently. Coherence irregularities are often seen in people with traumatic brain injury, learning disabilities and autistic spectrum disorders.

3) Phase: is a measure of the speed the signals travel through your brain. The brain’s ability to process information can be compromised if the signals are moving too fast or too slow from one part of the brain to another. You can think of phase as being similar to having a conversation with someone. If they talk at a regular pace they are easy to understand, but if they speak very quickly you can have trouble understanding them, or if they talk very slowly you also have issues understanding of following the conversation. Phase deviations indicate the brain is not working smoothly.

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