“Everything Old Is New Again”

Revised diagnostic tool proves effective in fight against depression.

Though it is commonly referred to as a brain disease, depression is in fact a multifactorial illness that impacts over 25 million people each year. Sadly, one-third of those people fail to respond favorably to traditional psychopharmacological modalities and suffer from what is known as treatment-resistant depression.Brains graphic courtesy of Psychiatric Associates of Southwest Florida.

The search for a unique tool to aid those suffering from treatment-resistant depression rages on, and in the past decade great success has been found through the use of genomic testing and advanced therapies such as transcranial magnetic stimulation (TMS), intravenous ketamine infusion and theta burst stimulation (TBS).

Proper diagnosis remains a critical factor, however, and while rating scales, clinical assessments and Mental Status Examinations remain at the center of this process, neuro-imaging is now coming to the forefront along with the resurrection of an old tool.

Once known as Computerized Topographical Brain Mapping, that tool is now referred to as Quantitative Electro Encephalograms, or QEEG Brain Mapping. It is a revised form of electroencephalography, or EEG, which is the measurement of the electrical patterns found at the surface of the scalp that reflect cortical activity. These patterns are commonly referred to as brainwaves. Quantitative EEG is the computer analysis of digitized EEG activity.

A New Twist

“In referring to QEEG, I tend to agree with the song “Everything Old Is New Again,” written by Peter Allen, because EEGs were used to measure brainwaves back in the 1980s,” says Robert Pollack, MD, a psychiatrist who employs QEEG at his Fort Myers-based practice.

“The difference is that back in the Eighties, all we got from these tests were squiggly lines that were difficult to interpret. With QEEG, we get those results in the form of color images, or brain maps, that are much easier to read and make use of.”

Dr. Pollack says QEEG is currently being used primarily to determine whether a patient with treatment-resistant depression will respond better to one of two specific advanced therapies – TMS or TBS.

Discovered by a team of researchers at the Medical University of South Carolina in the 1980s, TMS uses short 10Hz magnetic pulses while TBS uses 50Hz pulses to rouse the part of the brain that is underactive in people who suffer with depression.

“The difference is that back in the Eighties, all we got from these tests were squiggly lines that were difficult to interpret. With QEEG, we get those results in the form of color images, or brain maps…” – Dr. Pollack

These magnetic pulses are similar to those used in MRI stimulation, and are delivered through a paddle-shaped device with a magnetic coil that is placed on the prefrontal cortex while the patient rests in a comfortable chair similar to a dentist’s chair.

The biggest difference between the noninvasive TMS and TBS treatments, the latter of which gained FDA approval in 2018, is the amount of time required for each treatment session and the number of sessions prescribed during a typical treatment period.

TMS treatment sessions last approximately 19 minutes each, and a typical TMS treatment protocol calls for patients to receive a total of 36 treatments over a period of six to eight weeks.

TBS treatment sessions last only three minutes and are typically administered once a day at a derivative of the motor threshold, which is the stimulation strength at which a minimal motor response is evoked.

“Motor threshold is the amount of energy required to apply a current to the left temporal area that results in your right thumb wiggling involuntarily,” Dr. Pollack educates. “When we see that wiggle, we know we’ve hit the right spot.”

Finding that right spot is another advantage that QEEG allows for. To apply TMS or TBS stimulation properly, mental health experts must first decide whether to treat the right side or the left side of the dorsolateral prefrontal cortex.

“What we look for is low activity in theta and/or alpha region,” Dr. Pollack says. “With most people that low activity is found on the left side. In those cases, the left side of the prefrontal cortex is where we treat.

Brains graphic courtesy of Psychiatric Associates of Southwest Florida.

Depressed Brain vs. Normal Brain

“However, with about eight percent of the people, we find that low activity on the right side. When that’s the case, the treatment should be done on the right side, not the left side. So, QEEG helps us to be more specific in terms of where we treat each patient.

“By using QEEG we can not only determine if TMS or TBS will work best for a patient but what side of the brain needs to be treated and what voltage is desired. If we see a spike in the 10Hz area we know that TMS can be done. If not, we look to using TBS or ketamine. So QEEG is really an invaluable tool.”

Quick and Easy

QEEG testing is a quick, noninvasive and completely painless process that takes only about 10 minutes to complete. While resting comfortably in a chair, the patient is fit with a specially designed headset that collects data through a series of electrodes and feeds it into a database.

“Another thing that QEEG allows us to do is track the changes in brain function that are achieved through the various treatments,” Dr. Pollack adds. “Because we can see those changes on a colorized map of the brain, we can actually show a patient the progress that’s being made through the treatment.

“This is just another example of how, as we move forward, we are finding that more of the tools of yesterday are being modernized by technology, and through that modernization we are able to make better and better decisions about uses of existing treatments while also finding even new ones.”

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