Arterial Pulsations Are Unrelated to the Throbbing Quality of Acute Pain (P04.244)

Abstract

Objective: We recently reported that the heart rate and subjective throbbing rate in patients with migraine do not correspond, but were unable to establish the generality of this finding, nor were we able to rigorously test the possibility of a more subtle relationship between throbbing percepts and the peripheral arterial stimulus.Thus, in order to establish an independent neurobiological basis for this percept, we recorded subject reports of the throbbing rhythm while simultaneously recording the arterial pulse in subjects with acute dental pain, a pulsatile pain condition of indisputable peripheral origin. Background When severe and disabling, pain is often throbbing or pulsatile. The prevailing scientific view holds that this throbbing quality, such as in migraine, is a primary percept, arising directly from the mechanical activation of pain-sensory neurons closely apposed to blood vessels. Design/Methods: This was a cross-sectional study of the throbbing percept in a dental clinic. Results: We found that throbbing and arterial pulse rates had no correlation, and that the two rhythms showed no synchrony. Moreover, arterial and throbbing rate variability displayed distinct fractal scaling properties, implying that the mechanisms underlying these complex rhythms are unrelated. Conclusions: The present refutation of the “vascular theory” of throbbing percepts suggests an alternative possibility, that a CNS “pacemaker” underlies throbbing percepts, and could lead to novel treatment strategies for pain. Disclosure: Dr. Ahn has nothing to disclose. Dr. Mirza has nothing to disclose. Dr. Mo has nothing to disclose. Dr. Holt has nothing to disclose. Dr. Kairalla has nothing to disclose. Dr. Heft has nothing to disclose. Dr. Ding has nothing to disclose.