Quantitative EEG (QEEG)
Quantitative EEG (sometimes referred to as brain mapping or QEEG) and neurofeedback (also known as EEG biofeedback or neurotherapy), is the measurement through digital technology of electrical patterns at the surface of the scalp, which primarily reflect cortical electrical activity or “brainwaves.” QEEG is one of the more reliable tests in demonstrating and quantifying white matter pathology. Since 1989 with the work of Thatcher, et. al. on mild head trauma, use of QEEG for accurate diagnosis has become routine. The work has been validated, replicated and reviewed in the literature by experts in refereed journals, meeting the strictest clinical standards in medicine; a sampling of references is at the end of this article.
The American Medical EEG Association Ad Hoc Committee on QEEG has stated that QEEG “is of clinical value now and developments suggest it will be of even greater use in the future,” Duffy F, Hughes J, Miranda F, Bernad P, Cook P. The Status of Quantitative EEG (QEEG) in Clinical Practice, Clinical Electroencephalography, 1994, 25, 6-22.
Since 1977, there are over 2,000 publications in journals and books of studies concerning the clinical application of computerized EEG to a wide variety of disorders. QEEG has scientifically documented ability to aid in the evaluation of conditions such as mild traumatic brain injury, ADD/ADHD, learning disabilities, stroke, epilepsy, and to predict outcomes from treating conditions such as ADD/ADHD, alcoholism and drug abuse.
Using neurofeedback to treat conditions has been scientifically documented to be successful with ADD/ADHD, closed head injuries and addictions. The American Psychological Association has also endorsed QEEG and neurofeedback as being within the scope of practice of psychologists who are appropriately trained, and there are national associations for professionals from multiple disciplines who are utilizing these procedures.
The procedure for a QEEG takes about 1½-2 hours. It is non-invasive, and no electrical current is put into the brain. It consists of placing a snug cap on the head which contains small electrodes to measure the electrical patterns coming from the brain–much as a physician listens to the heart from the surface of the skin. Information is gathered on the brainwave patterns and the efficiency of communication between different parts of the brain. This is done while the client sits with eyes open, then eyes closed and while doing one or two cognitive tasks. After the client leaves the office, there is a lengthy office procedure to remove any artifacts that occurred when the eyes moved or blinked, facial muscles tightened or the client moved slightly in the chair.
This artifacted data is then compared to a number of sophisticated data bases of the brainwaves of persons of the same age and sex who have been intensely screened for normality. This highly statistically accurate analysis is more sensitive than MRI, CT scan or neurological examination in diagnosing white matter injury, since it measures microscopic changes.
This assessment procedure allows us to then determine in a highly scientific, objective manner whether and how a client’s brainwave patterns are significantly different from what would be expected. The QEEG assists in knowing if there are abnormalities in brain function that neurofeedback might be helpful in treating and how to individualize neurofeedback to the unique problems of each client. For example, there have been numerous subtypes of ADD/ADHD which have been identified in recent scientific research–none of which can be diagnosed from observing the person’s behavior. Unfortunately, some clinicians apply a standardized intervention based only on the fact, for example, that someone has been diagnosed with ADD/ADHD, according to the person’s behavioral symptoms. However, a sophisticated QEEG allows a much deeper look and provides the information to tailor treatment to each individual client’s needs.