Cortical involvement during the description of head pain

Abstract

Pain perception involves several cortical areas. Our purpose was to examine cortical activity in patients describing their cephalic pain with the MacGill Pain Questionnaire (MPQ). Two SPECT analyses were performed in pain-free periods in 10 patients with migraine (n=8) or myogenous facial pain (n=2). The MPQ was administered in the first session, while no task was to be performed during the second session. Differences were calculated using statistical parametric mapping (SPM99), also taking the MPQ pain rating index (PRI) as covariance. During the MPQ session, clusters of activation were observed in the orbitofrontal cortex, the insula and the anterior cingulate cortex (ACC) of the left brain, but not significantly so. Using the MPQ PRI as covariate, significant areas of activation were found in the left frontal lobe, the Brodmann area 32 and in the ACC. The description of pain seems to activate cortical areas similar to those involved in actual pain perception.