Abnormal brain processing of cutaneous pain in migraine patients during the attack

Abstract We examined cutaneous pain thresholds using CO 2 laser stimuli during migraine attacks, and defined the evoked cortical potential characteristics. Ten patients without aura were studied during attacks and for at least 72 h subsequently. Pain stimuli were generated on the dorsum of both hands and the right and left supraorbital zones, using pulses from a CO 2 laser. Absolute latencies of scalp potentials were measured at the highest peak of each response component, and the peak-to-peak amplitudes of N2a–P2 components were recorded. Cutaneous pain thresholds were significantly reduced on both the symptomatic and non-symptomatic sides during the attack, in comparison with the headache-free phase. The N2a–P2 complexes also increased in amplitude during attacks in comparison with the pain-free side. Thus, cutaneous hyperalgesia occurs during migraine attack, and is subtended by central sensitization phenomena, probably involving the cortex.