Large Changes to ProTools coming this week
Major changes to those of you using our ProTools software will be rolling out this week. The software you know and love is largely staying the same, but we have tweaked the way data sessions are viewed with a more efficient and intuitive data timeline. We are dedicated to providing updates to improve our system, and we think you'll find that this new version of ProTools is much faster and more intuitive.
Each data session is now a point on the data timeline, shown across the top of your screen. You can very quickly see a subject's progression across their recent testing sessions. Click on any testing session to see a full detailed report of the testing session below.
We're introducing radar plots to give you a new way of viewing the corticalmetrics of your patients. Poor results on the tests will draw the radar plot into the yellow or red region, and good performance will make the plot progressively larger and expose more green space.
The new tabular view will give you a better feel for how a subject has progressed across multiple testing sessions. Every test taken is displayed as a numerical value and its corresponding color-code. This allows you to more easily see if the subject is improving (moving from red to green) or declining (green to red).
How sensitive are cortical metrics?
An important principle in both brain circuitry and maintaining good neurological health is the balance between excitation and inhibition. Activity in the brain (mediated through neurons and neurotransmitters) can generally be classified as either excitatory or inhibitory. Too much excitation can result in seizures; without inhibition, excitation runs rampant and the brain cannot shut itself off. Too much inhibition and/or not enough excitation can also be detrimental. Ideally, this balance is maintained by neurotransmission that is mediated by NMDA receptors (which mediate the excitatory glutamate transmission) and by the inhibitory neurotransmitter GABA.
An inhibition/excitation imbalance affects mechanisms such as adaptation in the brain. One of the best ways to look at the impact of lower than normal GABA mediated inhibition is via test results from alcoholics (see examples below). As background, alcohol is a GABA agonist, which essentially means that the alcohol takes the place of GABA, and chronic alcohol consumption leads to an individual producing less GABA. Detoxification tremors, a result of an alcoholic not drinking, emerge because there is not enough GABA or inhibition in the individual’s system to deal with the imbalance in excitation and inhibition. Benzodiazepines, another GABA agonist, have been proven an effective treatment for recovering alcoholics, however, treatment with benzos is no longer recommended due to their highly addictive nature.
This graph compares the cortical metrics of a group of individuals pre- and post- treatment for alcoholism. Note that after a 12 week period of sobriety, the metrics were close to those obtained from controls.
In the next graph, cortical metrics demonstrates alterations in college aged individuals; those individuals who drank more than 60 drinks per month showed significant differences from individuals who drank less or did not drink at all.
A question that we are frequently asked is whether drinking, or acute alcohol consumption, can impact cortical metrics. Any substance which alters communication in the brain will have an impact on cortical metrics, and acute alcohol consumption is not an exception to that rule.
Note the differences in the scores in the next graph – the scores on left hand side reflect those obtained with low blood alcohol content (BAC) and the scores on the right hand side reflect those obtained with high BAC.
Changing the balance in excitation and inhibition can also be achieved by decreasing excitation. Administering a small amount of dextromethorphan (DXM; commonly found in cough syrup) will significantly change an individual’s cortical metrics.
The chart below compares individuals receiving a placebo (control group) with individuals receiving a double dose of cough syrup.
There are different types of inhibition which are mediated through GABAa and GABAb. Although GABA levels in the brain can be measured with spectroscopy, there are no methods for measuring this directly. However, differentiating between GABAa and GABAb is something that cortical metrics can theoretically accomplish, and there is growing evidence for the rationale in a number of studies. We’ll describe that work in a future article.