Differences in trigeminal and peripheral electrical pain perception in women with and without migraine
Pain perception studies in migraine patients have shown trigeminal and peripheral pain facilitation during the migraine attack. We were interested in differences of trigeminal and peripheral pain perception between migraine patients during the migraine interval and healthy subjects. Perception of electrical pain stimulation was measured in 20 migraine subjects outside a migraine attack (10 migraine with aura and 10 migraine without aura) and in 20 healthy subjects. We recorded sensory and pain thresholds, pain ratings after suprathreshold stimulation, and pain rating after two trains of repetitive stimulation (i.e., pain facilitation). Migraine subjects showed a significantly higher pain rating after suprathreshold stimulation in the trigeminal region as compared to healthy subjects (4.8 ± 1.6 versus 3.8 ± 2.2, p < 0.04 after Bonferroni correction) but not in the peripheral region. Furthermore, migraine subjects showed a pain facilitation after repetitive trigeminal stimulation whereas healthy subjects showed a pain habituation. We observed no significant differences between migraine subjects and healthy subjects for all parameters in the peripheral stimulation. Migraine patients with and without aura did not differ in any parameter. All subjects showed decreased sensory and pain thresholds after trigeminal as compared to peripheral stimulation. Migraine subjects show an increased pain perception after trigeminal but not after peripheral pain stimulation as compared to healthy subjects. This phenomenon is probably due to the observed pain facilitation after painful trigeminal stimulation.