Prefrontal cortical hyperactivity in patients with sympathetically mediated chronic pain

Citation
Av. Apkarian et al., Prefrontal cortical hyperactivity in patients with sympathetically mediated chronic pain, NEUROSCI L, 311(3), 2001, pp. 193-197
Citations number
13
Categorie Soggetti
Neurosciences & Behavoir
Journal title
NEUROSCIENCE LETTERS
ISSN journal
03043940 → ACNP
Volume
311
Issue
3
Year of publication
2001
Pages
193 - 197
Database
ISI
SICI code
0304-3940(20011005)311:3<193:PCHIPW>2.0.ZU;2-D
Abstract
Chronic pain continues to impose a large burden of suffering, yet its neura l correlates remain poorly understood. In sympathetically mediated chronic pain (SMP), peripheral sympathetic blockade temporarily relieves this pain, so that related neural activity can be studied without perturbing sensory inputs. We used functional magnetic resonance imaging and thermal painful s timuli applied to the chronically painful body site, before and after sympa thetic blockade, to examine the cortical network of chronic pain. The chron ic SMP state was associated with a widely spread prefrontal hyperactivity, increased anterior cingulate activity and decreased activity in the thalamu s contralateral to the body side suffering from SMP, but was unrelated to s ensorimotor activity. Ineffective sympathetic blocks, i.e. blocks that did not diminish the SMP pain, did not change the cortical responses to the pai nful thermal stimulus; while effective placebo resulted in similar response s to those of effective blocks. These findings provide evidence for abnorma l brain responses to pain in patients with chronic SMP, which engages prefr ontal/limbic networks more extensively than in acute pain-states. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.