Neurofeedback Databases: NX Link

I realize that I haven't been posting for the last three weeks. I was busy with college decisions and deciding which college to attend. But with that decided, I will once again post regularly.

In an earlier post, I explained the uses of the Neurorep database, and how I create maps using its saved files. However, Scottsdale Neurofeedback Institute's most heavily weighted database is the NX Link Database, created by New York University's Medical School.

Creating the Brainmaps

First, I the patient's raw EEG file is imported into the host computer folder. These files (for both Eyes Open training and Eyes closed) contain the patient's amplified brainwaves. Then topographic tables are normalized -- in other words, the brainmaps/keys are labeled in a select way. Each brainmap is color coded, each color depicting a level of standard deviation from the norm. Examples will be explained later in this post. Then, the maps and brainwave files are printed and combined into a single file, the most important of which is depicted below.

 

The brainmaps are separated into columns and rows: the columns are the different brainwaves, and the rows each display the EEG information in a different way. 

 

Absolute Power: (Row 1 above) This row compares the patient's EEG to a database of normal brains, comparing each brainwave to z-scored norms. For example, the patient's Theta waves are compared to normal levels of Theta waves for an individual of their sex, handedness, and age.

Relative Power: (Row 2 above) This row compares the patient's EEG to a database of normal brains, comparing the relative levels between all the brainwaves to the relative levels of the z-scored norms. For example, a patient's Theta levels might be high compared to the norm, but their Theta/Beta ratio could be normal. This would balance out the behavioral side effects that merely excessive Theta would cause.

Power Asymmetry:/Coherence (Rows 3 & 4 above) This row compares how much the brainwaves in each hemisphere compare to those of the other hemisphere. If there is a significant deviation, it could indicate communication problems between the different parts of the brain. The electricity flowing between those regions might be irregular, and, as a result, could help identify larger neurological problems. Coherence measures how fast the regions of the brain communicate with each other. If the brain's electricity is sluggish, or even over-connected, it could indicate a form of brain damage/traumatic brain injury.

Each different interpretation of the brainwaves gives the doctor a better understanding of each individual's unique situation. Just one interpretation is not enough to diagnose, as only multiple montages could produce a relatively accurate diagnosis. 

Discriminants

Although the brainmaps themselves can be valuable tools for diagnosis, the discriminant databases are designed specifically for this purpose. The NX Link database is stored with brianwave norms for various symptoms and disorders; they compare the patient's data to each norm to determine whether the disorder is a possibility or not. For example, the NX Link may determine, after analyzing the EEG, that a patient may have Attention Deficit Disorder because their brainmaps bear similarities to those of an individual with a common case of ADD. 

After assessing which symptoms/disorders are probably causing the problems (using brainmaps), I run the patient's file through each discriminant by testing them for each symptom. The system then prints the likeliness of the patient having/developing that disorder. While not being absolutely accurate, the discriminant tool of the NX Link is invaluable for diagnosis.