Quantitative Electroencephalogram (qEEG) & swLORETA
qEEG is a standard assessment of brain functioning in many health care offices and major medical centers throughout the country.
There are now over 170,000 peer-reviewed journal articles validating the scientific reliability and validity, and high clinical correlations, of qEEG posted on the National Library of Medicine's web page in Washington, DC.
We encourage you to refer to this database of objective, scientific research literature now and in the future whenever questions or concerns arise regarding qEEG or its clinical efficacy or application.
Other references are the web pages of the International Society for Neurofeedback and Research (ISNR), Association for the Advancement for Psychophysiology and Biofeedback (AAPB), and EEG and Clinical Neuroscience Society (ECNS). Dr. Robert McCarthy is a professional member of all these organizations and is Board Certified Fellow in Neurofeedback with the Biofeedback Certification International Alliance.
Conventional imaging technologies like CT, MRI, SPECT, and PET scans , along with analog EEG, look at the structure of the brain to determine whether everything is where it belongs, and that nothing is present that should not be there. In contrast, qEEGs are a functional measure of brain functioning that actually looks at how major brain regions work and interrelate to each other.
Unfortunately, abnormalities caused by the microscopic tearing and shearing forces responsible for syndromes like "post-concussion syndrome" and mild closed head injury are often missed by traditional radiographic techniques and can only be documented via the use of qEEG.
During the last 25 years, advances in computer signal processing and digital technology have made it possible to sample brain waves many times per second (usually 128 to 256 samples per second) and to save them for later retrieval, artifacting and analysis.
We can now precisely measure the amplitude and frequency of specific brain waves, be fairly exact about the scalp distribution of those waves, and even compare a client's brain waves at each of the major brain regions to an appropriate normative reference database using this state-of-the-art technology.
qEEGs document abnormalities in electrical relationships between various areas of the brain by comparing a recording under different conditions to a normative database. For example, when someone sits with their eyes closed, eyes open, or performs a specific task like reading or math.
qEEG testing during cognitive challenges allow us to examine the brain's response to these tasks. This is particularly interesting and valuable when evaluating children, adolescents, or adult with learning and attentional problems. We often see good activation of the EEG during some tasks, but very poor activation during other tasks such as listening, reading, or math.
qEEG is not intended to be a "stand-alone" diagnostic tool or substitute for other medical diagnostics. Like all forms of assessment, it is best understood within the context of other medical and standardized test results as another tool to aid in the diagnosis of various dysfunctional states, and never as a substitute for clinical judgment.
In addition, qEEG provides us with "targeted" information by suggesting meaningful electrode placement for conducting neurofeedback. Many clinicians believe that qEEG-driven neurofeedback is often more effective and cost-efficient than standard neurofeedback protocols.
There is well-documented scientific evidence that QEEG is a valuable tool in the diagnosis of mild traumatic brain injury, ADHD, asperger's, autism, learning disabilities, stroke, epilepsy, bipolar disorder, obsessive-compulsive disorder, etc. There is only a small number of clinicians in the United States properly trained to do qEEGs, and a limited number of clinicians providing neurofeedback services.
Unfrotunately, most physicians in your community are likely unfamiliar with the clinical application of qEEG and neurofeedback, and certainly are not familiar with the recent scientific qEEG research and clinical literature. qEEG applications for anxiety, epilepsy, and attentional deficits date back to the 1970s.
Although there are many QEEG systems on the market, our office is equipped with the latest state-of-the-art digital Deymed and Mitsar systems. The Deymed system is a 32-channel hospital quality unit that allows simultaneous recording of brain waves and evoked potential recordings while performing video recordings of muscle movement in a client's face.
With further development of an EEG-based functional imaging technique called swLORETA, or low resolution brain electromagnetic tomography, it can now be shown that the scalp's electric potential provides sufficient information for obtaining high time resolution information on the 3-D distribution of electric neuronal activity in the brain.
Therefore, swLORETA yields a spatial low-pass filtered version of cortical density, with correct localization. swLORETA images provide high time resolution electric neuronal activity information by making use of the human head model described in the Talairach brain atlas.
qEEG artifacting and qEEG and swLORETA analysis services are available worldwide via the Internet.