Disrupted functional connectivity of the pain network in fibromyalgia

IGNACIO CIFRE; CAROLINA SITGES; DANIEL FRAIMAN; MIGUEL MUÑOZ; PABLO BALENZUELA; A GONZALEZ-ROLDAN; MARTINEZ-JAUAND M; N BIRBAUMER; DANTE CHIALVO; PEDRO MONTOYA

PSYCHOSOMATIC MEDICINE

LIPPINCOTT WILLIAMS & WILKINS

Año: 2012 vol. 74 p. 55 - 62

0033-3174

It has been repeatedly shown that chronic pain may lead to an altered activation of the pain matrix. Nevertheless, no information exists about a possible impact of lasting pain on brain dynamics during resting. In the present study, functional connectivity of the pain matrix and other resting-state networks were examined in patients with fibromyalgia (n=9) and healthy controls (n=11) using functional magnetic resonance imaging (fMRI). Partial correlations among activation time- series of seed voxels located at specific areas of the pain matrix were calculated to evaluate functional connectivity within pain-related brain areas. Seed correlations showed an altered connectivity of brain areas involved in the pain network. Fibromyalgia patients exhibited increased correlations between ACC and insula, as well as decreased correlations among ACC, amygdala, thalamus and PAG when compared with healthy volunteers. These results demonstrate that widespread alterations of pain processing in fibromyalgia, already described in response to nociceptive stimuli, are also present in brain dynamics at rest, probably reflecting permanent tonic nociceptive neuronal pattern. Moreover, our findings further suggest that the disconnection between subcortical pain modulatory areas (such as thalamus and PAG) in fibromyalgia might be related to a reduced inhibitory pain mechanism, which could be causally involved in the maintenance of the chronic pain disease.