Posted by Jack (24.190.201.93) on December 18, 2000 at 20:17:21:
The following is taken verbatim from the 2000 World Headache Symposium.
Pain intensity is a key subjective complaint that is used in a comprehensive assessment of pain. The degree of pain is subjective, however, and the personal criteria used to attach the label of pain to a specific sensation vary between and within individuals.
May and coworkers[15] from the Institute of Neurology at Queens Square Hospital in London, England, and University of Regensburg, Regensburg, Germany, used PET to study the brains of 9 patients with cluster headache during the acute cluster headache attack. Their goal was to discover whether the patients' reports of the degree of pain, using the visual analog scale, correspond to the activity in cortical areas known to be involved in pain, as estimated by changes in regional cerebral blood flow. The results are fascinating: Activation of the anterior cingulate cortex, thalamus, and insula cortex was highly correlated with subjective headache ratings, showing significantly more activity when pain ratings were high and less activity when ratings were low. Thus, the activation of central sites is not an all-or-nothing reaction to sensitive or noxious input; the degree of activation is closely linked to the subjective degree of pain in each individual.
Could this be a first step to objectively measuring pain? One hundred years from now, in medicolegal proceedings, will we actually be able to reliably correlate subjective complaints of pain with objective imaging or other findings?