In the simplest terms, quantitative electroencephalography (qEEG) is the process in which the constant electrical activity of the brain is transformed into digital information and pictures, providing an explicit snapshot of the brain’s activity. It takes the derived data, and compares it to a database to determine the hyper- and hypoactivity within different brain regions, illustrating functionality. Presently, the qEEG has been utilized in over 120,000 research articles, and is considered a objective measure of mild traumatic brain injuries (concussions) in the courts of the United States. It’s highly reliability and test-retest scores are also evidence for its credibility. There are 4 main types of injuries that can be readily assessed following a concussion, and the qEEG analyzes all of these issues:
(See Mechanism of Injury for more information on the physiology of concussion.)
The qEEG (quantitative electroencephalograph) collects data in a manner similar to that of the medical profession, but instead, uses computers to analyze the data. The data is statistically analyzed and compared to a database to provide a snapshot of how the areas of the brain are working and communicating in comparison to others. This process has allowed for the development of sub-programs such as the “Mild Traumatic Brain Injury Index or MTBI.” This index allows for the examination of the various areas of the brain most commonly concussed, and how these areas communicate. Results have been accepted as an objective measurement of brain injury by the courts in the United States.
The raw signals from the qEEG are converted into numbers called Z Scores (above). The Z score represents the amount of electrical power at each site. This allows for comparison to a set of established norms (database), comparing the analyzed brain to the rest of the world. Zero represents normal activity, and higher numbers (positive or negative) reflect whether the electrical activity is hyper (too much) or hypo (too little).
Z Scores are then converted into a pictorial format for ease of understanding (above). The top row reflects the absolute power in frequencies at each site. For example, in the upper middle there is an area of blue, reflecting decreased activity in the Alpha brain frequencies. This is associated with problems in multitasking and day to day functioning. In the second row there is an area of orange in the Delta frequencies, which reflects problems with sleep and issues with depression and chronic pain. The middle row is not routinely utilized in this clinic. The fourth and fifth rows show a bunch of lines, each indicating the connections not working together. This is associated with reduced cognitive efficiency, commonly seen post-trauma. There is no other instrument on the market that can empirically do this.
The LORETA offers a chance to explore the deeper parts of the brain. In the illustration above, the top of the brain is in the upper left image. Moving from left to right, each slice is 7mm lower than the preceding one finally arriving at the brain stem. The red shows the maximally irritated parts of the brain.
The charts above show the probability (95.0%) that an individual has a mild traumatic brain injury (concussion). The lower chart shows the severity of the injury (5.02 out of 10). These charts also indicate which specific sites have been injured. This information has been admitted into the courts in the United States as objective evidence of a brain injury.
The SEMG (surface electromyograph) measures the electrical activity of the muscles of the neck to determine how they function. In a concussion external forces are applied to the head which stretch the muscles of the neck causing a whiplash. In addition rotational forces impact the brain producing a number of symptoms including issues of balance, sleep and vision. A whiplash should be considered when the concussed presents with these symptoms and with headaches. The SEMG allows for objective assessment of the neck and damaged muscle(s), which then can be fixed to reduce, if not eliminate that part of the concussion. An example of SEMG tracing of a whiplash is illustrated.