Altered pain processing in children with migraine: an evoked potential study.

In adults, evidence is accumulating that migraine is associated with altered central processing of pain stimuli and, possibly, changes in the allocation of attentional resources to such stimuli. In pediatric migraine, however, little is known about altered pain processing. We examined 15 children with migraine and 15 controls (age 10-15) in an oddball standards task. Children had to respond to rare targets (tones) and ignore frequent painful (pain threshold) or non-painful mechanical standard stimuli while evoked potentials were obtained. Painful as compared to non-painful stimuli elicited significantly larger N150, P260 and P300 components of the somatosensory evoked potential in all children. The pain-evoked N150 and P260 components did not differ significantly between groups. However, in children with migraine, both painful and non-painful standard stimuli were associated with significantly larger P300 amplitudes at significantly shorter latencies. Perceived intensity of the painful and non-painful stimuli was comparable in both groups. The evoked potentials and reaction times to the target tones did not differ significantly between groups. Habituation across trials was similar in both groups. Hence, children with migraine may display an automatic attentional bias towards painful and potentially painful somatosensory stimuli. Consistent with the psychobiological perspective of chronic pain, such an attentional bias could constitute an important mechanism for migraine becoming a chronic problem.