What is QEEG?

Quantitative Electroencephalography (qEEG) measures the strength and nature of the brain wave activity generated in the brain cells and maps them accordingly. It does this by putting a lot of rubber-padded electrodes in the right places to pick up your brainwave patterns.

QEEG Brain Mapping

Quantitative electroencephalography does its job by "color coding" the areas to build brain maps of your cortex after processing the brainwave patterns received through electrodes.

Therefore, it is also called "brain mapping," as it highlights the “hot spots,” which are the pathological areas of the brain.

Brain mapping visualizes normal and abnormal brain functions. These brain maps help make clinical decisions regarding which brain regions may require proper interventions.

What does your qEEG tell you?

A qEEG brain map can help clinicians evaluate brain function by studying real-time patterns of electrical signals in your brain. It can tell you if your brain is having a hard time processing cognition and emotions and reveal your brain's stress levels.

These brain wave patterns can identify ADHD, anxiety, fear, depression, schizophrenia, dementia, or regions of cerebral stroke, traumatic brain injury, autism spectrum disorder, and mood disorders.

QEEG VS. EEG

Conventional Electroencephalography (EEG) captures and records the brain waves and presents them on a graph showing peaks and troughs, which tells us about brain function. 

In quantitative EEG, recorded digital EEG data is statistically analyzed using complex algorithms. It takes the help of modern analytic software and database reference values and builds a color-coded brain map.

QEEG Test Results In ADHD?

qEEG testing for ADHD is recommended when clinical suspicion from psychological assessments is insufficient. Clinicians study 3 types of waves on EEG recordings.

The American Academy of Neurology (ANN) suggests looking for two landmark features in a quantitative electroencephalogram:

• The most significant features of a qEEG observed in ADHD are the high power of slow brain waves (theta waves, 4-7 Hz) and the low intensity of fast brain waves (beta waves, 14-30 Hz). Theta/Beta Ratio (TBR) measured at the vertex of the scalp is the most robust parameter for assessing ADHD. Alpha brain waves can show variable patterns.
• In ADHD, qEEG records unusually high theta activity in the frontal lobe. The function of the frontal lobe decreases. This frontal region is responsible for our thoughts and perceptions.

QEEG Neurofeedback therapy

Neurofeedback is a protocol designed according to the data received on quantitative electroencephalography, as we can then visualize the dynamic changes occurring in the brain wave patterns in real time.

With the help of this protocol, we can plan and implement behavioral reinforcement to help you consciously control your brain’s electrical activity. Clinicians do it through coaching exercises, visual and auditory cues, and direct feedback on electrical brain activity. 

A couple of studies done in 2012 and 2019 have revealed increased rates of treatment response and remission and decreased rates of recurrences of ADHD. Therefore, qEEG can be used as a diagnostic tool as well as a clinical tool.

Event-Related Potential

What is ERP?

ERP stands for Event-Related Potential, also commonly known as stimulus-evoked potential. As the name suggests, it measures dynamic changes in the brain’s electrical activity when we introduce a sensory, cognitive, or motor event or stimulus.

How does ERP work?

Scientists compare brain electrical activity from EEGs before and after the introduction of the stimulus.

ERP measures several cognitive, sensory, and motor parameters of the ADHD brain. These parameters are abnormal in ADHD, so ERP should yield comparatively different EEG findings on the evoked response.

Can ERP diagnose ADHD?

A decade-long study reveals considerable evidence of consistently relevant ERP findings in the ADHD brain. ERP, in combination with machine learning algorithms has significantly improved the diagnosis of ADHD. 

What does ERP tell you?

Scientists compare the positive peak on the graph obtained at 300 milliseconds on the EEGs before and after the introduction of stimuli. As a result, this specific point is known as P300 or P3 amplitude.

An ADHD brain will have a lower P3 amplitude (decreased height). Many studies have consistently revealed comparable findings. 

P3 amplitude in ADHD

Decreased P3 amplitude indicates diminished attention, an inability to control their actions, and difficulty processing and evaluating target stimuli.

However, we must remember that P3 amplitude is highly variable between genders and at different ages. This reflects the evolution of P3 from a neurodevelopmental perspective. 

Conclusion

ADHD is a neurodevelopmental disorder that can severely halt normal brain development and pose many personal and social issues. Psychological assessment is the go-to method for diagnosing ADHD. However, brainwave studies can help assess and monitor this disorder when this method is inconclusive.

1. qEEG is a method of building a brain map of the cortex based on brain wave patterns. ADHD is marked by a deranged theta/beta wave ratio (TBR) at the vertex and high theta activity in the frontal lobe. Neurofeedback helps monitor and introduce interventions where needed.
2. ERP measures the evoked-brain activity after introducing sensory, cognitive, and motor stimuli. An ADHD brain is marked by decreased P3 amplitude.