Low heat pain thresholds in migraineurs between attacks

Background/Objective: Between attacks, migraine is associated with hypersensitivities to sensory stimuli. The objective of this study was to investigate hypersensitivity to pain in migraineurs between attacks. Methods: Cutaneous heat pain thresholds were measured in 112 migraineurs, migraine free for ≥48 hours, and 75 healthy controls. Pain thresholds at the head and at the arm were compared between migraineurs and controls using two-tailed t-tests. Among migraineurs, correlations between heat pain thresholds and headache frequency, allodynia symptom severity, and time interval until next headache were calculated. Results: Migraineurs had lower pain thresholds than controls at the head (43.9°C±3.2°C vs. 45.1°C±3.0°C, p=0.015) and arm (43.2°C±3.4°C vs. 44.8°C±3.3°C, p<0.001). There were not significant correlations between pain thresholds and headache frequency or allodynia symptom severity. For the 41 migraineurs for whom time to next headache was known, there were positive correlations between time to next headache and pain thresholds at the head (r=0.352, p=0.024) and arm (r=0.312, p=0.047). Conclusions: This study provides evidence that migraineurs have low heat pain thresholds between migraine attacks. Mechanisms underlying these lower pain thresholds could also predispose migraineurs to their next migraine attack, a hypothesis supported by finding positive correlations between pain thresholds and time to next migraine attack.