Date Published: November 24, 2009
Publisher: Public Library of Science
Author(s): Lino Becerra, Will Harris, Margaret Grant, Edward George, David Boas, David Borsook, Justin Harris. http://doi.org/10.1371/journal.pone.0008016
Abstract: Pain is difficult to assess due to the subjective nature of self-reporting. The lack of objective measures of pain has hampered the development of new treatments as well as the evaluation of current ones. Functional MRI studies of pain have begun to delineate potential brain response signatures that could be used as objective read-outs of pain. Using Diffuse Optical Tomography (DOT), we have shown in the past a distinct DOT signal over the somatosensory cortex to a noxious heat stimulus that could be distinguished from the signal elicited by innocuous mechanical stimuli. Here we further our findings by studying the response to thermal innocuous and noxious stimuli.
Partial Text: Recent work in the field of neuroimaging (fMRI) of pain has suggested some potentially specific biomarkers for pain and analgesics. By using a non-invasive easily applied system (DOT) to measure cortical brain activity in a similar manner to fMRI we can evaluate specific brain responses in chronic pain conditions, in which evoked pain reflects the patient’s symptoms, and make an assessment of pain intensity levels. Furthermore, this approach can be used to study the response to analgesics in an outpatient setting. At this time, measures of pain or response to analgesics are dependent on self-reports. “Amid the difficulties and uncertainties of investigating drug action in man and attempting to quantify drug effect, visual analogue scales, without the need for complex equipment and difficult experiments, have emerged as a tempting prospect” . The development of objective measures will allow for a quantifiable measure of pain and analgesia. Currently no objective measure exists.