Sometimes referred to as “brain mapping,” QEEG is used to measure cortical activity and evaluate brain function. Hemispheres Psychology & Neurotherapy use QEEGs to assist in identifying issues with abnormal brain function, to inform neurofeedback therapy, and to monitor our client’s therapeutic progress.
EEGs are safe and painless and are simply a recording of the electrical activity in the brain. EEGs can detect abnormal brain waves after a head injury, stroke, or brain tumour. Other conditions such as dizziness, headaches and migraines, dementia, sleep issues, seizure activity, ADHD, ASD, processing and learning difficulties, and serious mental health issues may also show abnormal brain activity.
The first step towards a QEEG is completing an electroencephalogram or EEG. An EEG is an assessment, which measures the electrical-chemical reactions of neurons across the scalp of the cerebral cortex. Tiny cup-like sensors capture the signal, which is then amplified by the EEG recording machine. Some doctors and clinicians use “caps,” which look like cloth swimmer’s caps with the leads sewn into them at the precise locations of the International 10-20 System (see image below). There are 19 sites that are universally accepted and allow fellow doctors and clinicians to discuss certain regions and ensure everybody is on the same page.
10-20 Electrode System
What does the “Q” stand for?
The “q” is for the quantitative analysis performed to the raw EEG data collected. Psychologists and neurotherapists utilise additional software programs to identify areas of the brain that are under or over-activated and look for correlations of these brain patterns that have been documented in psychological and/or behavioural concerns.
To determine whether your measures are likely to be associated with your concerns, your EEG brain activity is then compared to one or more databases. Most databases compare your EEG measurements to those of a large number of so-called “normal” people to see if you are statistically different from them. Other databases compare your EEG to groups of people with a certain disorder, to see if you are statistically similar to them.
What is measured by a QEEG?
The electrical energy of our brain communicating is also referred to as brainwaves. Neurons communicate and connect with other neurons via electrical events called action potentials. The frequency at which they do this is measured in hertz (Hz) or cycles per second. There are four main categories of brainwaves, which correlate to the observed mental state as follows:
- Delta .5 – 3.5 Hz (cycles/second) – associated with sleep
- Theta 4 – 7.5 Hz – dream-like state, reflective, creative inward thought, also associated with light sleep and deep meditation
- Alpha 8 – 12 Hz – a state of awareness but also relaxed, with an “in the now” focus
- Low Beta 12 – 15 Hz (SMR in a particular region) – associated with mind/body calmness
- Beta 15 – 20 Hz – mental alertness, processing and good analytical focus
- High Beta 20 – 30+ Hz – an overactive brain, featuring anxiety, obsessive and/or racing thoughts, and panic symptoms.
What’s involved with a QEEG?
Preparing for your EEG
Wash your hair either the night before or the day of the test, but don’t use conditioners or hair products. Try to get a good night’s sleep and eat a protein-based breakfast. Avoid caffeine on the day of the test or at least 2 hours beforehand as it can affect the results. If you are sick you should let us know as we may need to reschedule your EEG to another day. Also, take your usual medications unless instructed otherwise.
Getting ready for your EEG
After you have completed the necessary registration and consent forms to complete an EEG, your EEG technician will conduct an intake questionnaire and ask you about your mental and physical health, your current areas of concern, and your history of head injuries.
During your EEG recording
You feel little to no discomfort during an EEG. The electrodes don’t transmit any sensations. They just record your brain waves. Your technician will measure your head to choose the correct size EEG cap for your head. Because some electrodes are placed on your forehead, as well as your ear lobes, areas of your skin will be exfoliated to ensure the electrodes make good contact to improve the quality of the EEG recording. During the recording, it is important to sit quietly, follow your technician’s instructions and try to stay relaxed. Your technician will be focused on making sure you are comfortable and also on reducing unnecessary electrical disturbance in your EEG recording called artifacts. Our goal is to obtain a clean recording, which will assist with an accurate analysis of your brain activity.
After your EEG
Your technician will review, analyse and interpret your EEG recording and produce a report called a QEEG. With your consent, your EEG results may be discussed with other EEG trained specialists or referred to an external EEG analysis service for a highly detailed QEEG report.