Because pain is a subjective experience, patients are often asked to describe their pain in words. The result is a rich set of adjectives like sharp, dull, burning, and throbbing. In particular, a throbbing quality often describes pain that is severe and disabling. It was commonly thought such patients were sensing the actual pulsing of blood through their arteries. Apparently not, say researchers at the University of Florida in Gainesville.
Andrew H. Ahn in the Department of Neurology in the medical school and colleagues began by noting that throbbing pain has been associated with a wide range of painful conditions, including nerve injury, leading them to suspect that the throbbing reflected something going on in the nervous system. Then they had occasion to study a woman with a history of throbbing pain from daily migraine headaches. She was successfully treated so her headaches resolved but she continued to experience chronic throbbing sensations in her head (without pain). She volunteered for an electroencephalogram (EEG) study, which would record brain wave activity while she simultaneously used a digital recorder to tap out the throbbing rhythm she felt. The results showed that her throbbing beats had no relation to her heart rate, but were in perfect synchrony with alpha wave activity in her brain. Alpha waves represent a large- scale synchronous activity of brain nerve cells, which are thought to be the basis for communication across distant but functionally related brain regions.
By Joan Wilentz, TMJA