Throbbing Pain Has Nothing to Do With Your Heartbeat

We’re all familiar with the throbbing type of pain; the throbbing headache, the toothache that pounds away, the sudden twinge of a stubbed toe. That pain might thud like a heartbeat, but scientists have found the sensation is actually coming from your brain waves.

This is a discovery that could change how researchers look for therapies for easing pain, said Dr. Andrew Ahn, the University of Florida neurologist co-authoring the paper published in the July issue of the journal Pain.

“Aristotle linked throbbing pain to heart rhythm 2,300 years ago,” says Ahn. “It took two millennia to discover that his presumption was wrong.”

That throbbing quality to pain is something that doctors have long associated with arterial blood pulse at the injury location. Some medicines even targeted constricting the blood vessel walls to try lessening the effect.

“Current therapies for pain do not adequately relieve pain and have serious negative side effects, so we thought that by examining this experience more closely we could find clues that would lead us to improved therapies to help people who suffer from pain,” Ahn said. “It turns out that we have been looking in the wrong place all along.”

Alpha Waves

Ahn’s research team had previously looked at the pulsations associated with throbbing pain while monitoring heart rate and found the two were not linked. You can confirm this yourself next time you are experiencing throbbing pain, by comparing your throbbing rhythm with your own pulse.

The researchers had not had an explanation for the true origin of the throbbing quality of pain, and now this study reveals some answers.

Through the use of an electroencephalogram, researchers found that the throbbing quality was correlated with a type of brain activity called alpha waves.

“We understand very little about alpha waves, but they appear to have an important role in attention and how we experience the world,” Ahn said. “In addition, by analogy to how a radio works, alpha waves may also act as a carrier signal that allows different parts of the brain to communicate with itself.”

It is not yet known exactly how alpha waves cause throbbing pain. But this research indicates that the experience of pain is linked more to how the brain works and not to the pulsations of blood at the location of the pain. Understanding this will allow researchers to design new studies to discover better treatments for pain, Ahn said.

Reference:

Does throbbing pain have a brain signature?
Jue Mo, Morris Maizels, Mingzhou Ding, Andrew H. Ahn
PAIN – July 2013 (Vol. 154, Issue 7, Pages 1150-1155, DOI: 10.1016/j.pain.2013.02.013

Image: Thomas Hawk/Flickr