Researchers have now discovered that the unpleasant experience of throbbing pain — such as when you stub a toe — is actually connected to the pulsing rhythm of alpha brain waves, not artery pulsations, as previously thought.
“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,” said Dr. Andrew Ahn, a neurologist at the UF College of Medicine.
“It turns out that we have been looking in the wrong place all along.”
“Aristotle linked throbbing pain to heart rhythm 2,300 years ago,” Ahn said. “It took two millennia to discover that his presumption was wrong.”
The finding could significantly change pain management therapies, Ahn said. He and his team reported their findings in the July issue of the journal Pain.
People who have suffered from a toothache or a migraine may have noted a throbbing quality to the pain that experts have long associated with arterial pulsations at the location of the injury. Some drugs even constrict blood vessel walls in an attempt to lessen the effects.
In the study, researchers examined a patient who suffered from a throbbing sensation that remained even after her chronic migraine headaches had been resolved.
The researchers simultaneously observed the patient’s feelings of throbbing pain as well as her arterial pulse and found that they were unrelated to one another, suggesting that the pulsing of blood from the heartbeat was not connected to the throbbing quality of pain.
Through the use of an electroencephalogram, however, they discovered that the throbbing quality was linked to a type of brain activity — 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.”
Scientists still aren’t sure how just alpha waves cause throbbing pain. But the current research suggests that the experience of throbbing pain is tied to how the brain works and not to the pulsations of blood at the location of pain.
Figuring this out will help researchers design new studies that will help bring about better treatments for pain, Ahn said.
Source: University of Florida