Abstract
Background and Aims: Low efficiency of Conditioned Pain Modulation (CPM) has been reported in migraineurs, reflecting their pronociceptive state. We sought to explore an additional aspect of pro-nociception – the waning of CPM across repeated applications – to determine if migraine patients exhibit a progressive decay of pain inhibitory capability over time.
Methods: Migraineurs (N = 13) and healthy females (N = 26) underwent 3 stimulation paradigms: habituation, parallel CPM (CPMp) and sequential CPM (CPMs) with ‘test-stimulus’ (30″ contact heat at 47.5°C) given simultaneously or after the ‘conditioning stimulus’ (60′ cold water immersion), respectively. First, habituation was examined by 5 repetitions of ‘test-stimulus’ in the lower leg. Then, trains of 4 CPMp and 4 CPMs were applied randomly. NPS rating was given at the end of each stimulus. Effects of patient group, CPM paradigm and time were examined via repeated measures ANOVA.
Results: Migraineurs had deficient CPM in comparison to healthy controls, regardless of the CPM-stimulation paradigm (p = 0.009). The overall effect of CPM was larger in the parallel paradigm than the sequential paradigm (p < 0.000). Further analysis of CPMp showed group X time interaction (p < 0.005) indicating stability in controls, but diminution of CPM across stimulation repetitions in migraineurs. Finally, CPMp waning (trial 4 – trial 1) correlated with maximal pain intensity during attack (r = −0.708, p = 0.049).
Conclusions: Waning of CPM is a newly described manifestation of the pro-nociceptive state in migraine. Reduced ability to inhibit pain along time might be a contributing factor in the maintenance of migraine attacks.
Methods: Migraineurs (N = 13) and healthy females (N = 26) underwent 3 stimulation paradigms: habituation, parallel CPM (CPMp) and sequential CPM (CPMs) with ‘test-stimulus’ (30″ contact heat at 47.5°C) given simultaneously or after the ‘conditioning stimulus’ (60′ cold water immersion), respectively. First, habituation was examined by 5 repetitions of ‘test-stimulus’ in the lower leg. Then, trains of 4 CPMp and 4 CPMs were applied randomly. NPS rating was given at the end of each stimulus. Effects of patient group, CPM paradigm and time were examined via repeated measures ANOVA.
Results: Migraineurs had deficient CPM in comparison to healthy controls, regardless of the CPM-stimulation paradigm (p = 0.009). The overall effect of CPM was larger in the parallel paradigm than the sequential paradigm (p < 0.000). Further analysis of CPMp showed group X time interaction (p < 0.005) indicating stability in controls, but diminution of CPM across stimulation repetitions in migraineurs. Finally, CPMp waning (trial 4 – trial 1) correlated with maximal pain intensity during attack (r = −0.708, p = 0.049).
Conclusions: Waning of CPM is a newly described manifestation of the pro-nociceptive state in migraine. Reduced ability to inhibit pain along time might be a contributing factor in the maintenance of migraine attacks.
| Original language | English |
|---|---|
| Pages | 112-112 |
| Number of pages | 1 |
| DOIs | |
| State | Published - 2011 |