RT Journal Article
SR Electronic
T1 A Comparison of Visceral and Somatic Pain Processing in the Human Brainstem Using Functional Magnetic Resonance Imaging
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 7333
OP 7341
DO 10.1523/JNEUROSCI.1100-05.2005
VO 25
IS 32
A1 Paul Dunckley
A1 Richard G. Wise
A1 Merle Fairhurst
A1 Peter Hobden
A1 Qasim Aziz
A1 Lin Chang
A1 Irene Tracey
YR 2005
UL http://www.jneurosci.org/content/25/32/7333.abstract
AB Evidence from both human and animal studies has demonstrated a key role for brainstem centers in the control of ascending nociceptive input. Nuclei such as the rostral ventromedial medulla and periaqueductal gray (PAG) are able to both inhibit and facilitate the nociceptive response. It has been proposed that altered descending modulation may underlie many of the chronic pain syndromes (both somatic and visceral). We used functional magnetic resonance imaging to image the neural correlates of visceral and somatic pain within the brainstem. Ten healthy subjects were scanned twice at 3 tesla, during which they received matched, moderately painful, electrical stimuli to either the midline lower abdomen or rectum. Significant activation was observed in regions consistent with the PAG, nucleus cuneiformis (NCF), ventral tegmental area/substantia nigra, parabrachial nuclei/nucleus ceruleus, and red nucleus bilaterally to both stimuli. Marked spatial similarities in activation were observed for visceral and somatic pain, although significantly greater activation of the NCF (left NCF, p = 0.02; right NCF, p = 0.01; Student's paired t test, two-tailed) was observed in the visceral pain group compared with the somatic group. Right PAG activity correlated with anxiety during visceral stimulation (r = 0.74; p < 0.05, Pearson's r, two-tailed) but not somatic stimulation. We propose that the differences in NCF and right PAG activation observed may represent a greater nocifensive response and greater emotive salience of visceral over somatic pain.