ID 247 – Cortical modulation of thermal detection and pain thresholds in migraineurs

Abstract

Objective To explore the effect of 10 Hz repetitive transcranial magnetic stimulation (rTMS) of secondary somatosensory cortex (S2) on thermal perception and pain in migraineurs. Methods We measured thermal detection and pain thresholds on the hand and forehead before and after real and placebo rTMS in 26 interictal, 7 preictal migraineurs and 31 headache-free controls. Thresholds, defined as difference from baseline (32 °C), were analysed with repeated measures ANOVA. Results rTMS of S2 increased hand heat pain thresholds in controls, but not in migraineurs ( p = 0.042). The effect was not significant when compared to placebo stimulation. rTMS increased hand cold detection thresholds in both groups ( p Conclusions rTMS of S2 had an analgesic effect on heat pain in controls compared to migraineurs. The effect-size was not large, however, i.e. of similar magnitude as the effects caused by placebo. Stimulation of S2 seems to alter detection thresholds primarily, possibly because pain is modulated by deeper brain structures, namely the medial operculum and insula. Key message rTMS of S2 had greater analgesic effect in controls compared to migraineurs, although not distinguishable from the placebo effect.