Daron Gordon Owen1,2, Collin Franklin Clarke3,
Sugantha Ganapathy3, Frank S. Prato1,4, Keith S. St.
Lawrence1,2
1Imaging Program, Lawson Health
Research Institute, London, Ontario, Canada; 2Medical Biophysics,
The University of Western Ontario, London, Ontario, Canada; 3Anesthesia
and Perioperative Medicine, The University of Western Ontario, London,
Ontario, Canada; 4Imaging, St. Joseph's Hospital, London, Ontario,
Canada
The
cerebral representation of acute pain is well established, whereas that of
tonic pain is not due to difficulties in applying functional imaging to
prolonged stimuli. We used arterial
spin labeling (ASL) to investigate the neural activation associated with
tonic muscular pain. The use of ASL
allows direct comparison between studies.
Compared to our previous study incorporating both acute and tonic
phases, we observed smaller CBF changes, and only in bilateral insula and
frontal gyrus, despite similar pain levels.
A likely explanation is that the acute phase of the previous study
induced anxiety and distress, whereas our tonic pain stimulus did not.