More than one-third of Americans suffer from chronic pain and no two individuals would describe their experience in the same way.
The severity of this problem has energized scientists to search for an objective measure of pain. Now, researchers at the University of Birmingham in England and the University of Maryland School of Dentistry in the U.S. say they have found one: electroencephalography (EEG).
EEG measures the brain’s electrical activity in the form of different kinds of waves, or oscillations. Of relevance to this study are alpha brain waves, the oscillations produced by the brain at rest when it is not processing much information. Alpha oscillations typically measure at speeds between 8 and 12 Hz, and these waves tend to be slower in chronic pain patients.
The purpose of the new study was to see if the speed of these waves in healthy people could predict pain sensitivity. Would people with slower alpha oscillations at rest be more sensitive to pain? The answer, they found, is yes.
The researchers took resting EEGs on 61 healthy men and women ages 21 to 42 to measure their alpha oscillation speed. They then performed two pain tests on them, one using a capsaicin cream and the other using applied heat.
Eight weeks later, they performed this same series again. During both sessions they found that the speed of the alpha oscillations seen during pain-free resting was a reliable predictor that individuals would be more sensitive to pain.
This new objective measure of pain sensitivity has important implications in treatment choices and post-operative planning.
There is also a growing body of research showing that biofeedback using EEG, called EEG neurofeedback, can help patients actually control these brain waves and effectively reduce their pain experiences.
A 2019 study of patients with chronic low back pain found that a series of 20 EEG neurofeedback sessions helped patients control their brain waves and pain sensations. The pain-relieving effect they achieved also lasted at least six months beyond the neurofeedback sessions.
Another study, a meta analysis of 21 research papers looking at pain and the use of EEG neurofeedback, reported similar findings. This paper was published in June 2020 in the European Spine Journal. The authors concluded that EEG neurofeedback “can be used to reduce the severity of pain and pain-associated symptoms such as sleep disturbances, mood disturbances, fatigue and anxiety in a number of chronic pain conditions.”
This has the potential to provide a lot of patients much-needed relief without the risk of prolonged drug use. The combined research presents a significant step forward in the objective measurement of pain as well as offering a novel treatment option.
As the authors of the 2019 study conclude: “Its excellent safety profile and availability as a home-use intervention makes it a potentially disruptive tool in the context of nonsteroidal anti-inflammatory drugs and opioid abuses.”