Thermal pain thresholds are decreased in the migraine preattack phase

Background and purpose: Migraine patients may have cutaneous allodynia during attacks. In order to investigate if pain physiology changes in the preattack phase we estimated heat pain and cold pain detection threshold (HPT and CPT) on three different days in 41 migraine patients and 28 controls. Methods: A thermode was applied at four sites bilaterally: forehead, face, neck, and hand. A subgroup of 11 migraine patients had been tested within 24 h before their next attack and in the interictal phase. Results: In the preattack phase, HPT was lower compared with the paired interictal recording for the hand (44.8°C vs. 45.9°C, P = 0.009), neck (46.8°C vs. 48.2°C, P = 0.02), and forehead (45.1°C vs. 46.3°C, P = 0.02). Neck and hand CPT were higher in the preattack phase than interictally (10°C vs. 7.3°C, P = 0.01 and 11.6°C vs. 9.4°C, P = 0.06, respectively). Preattack forehead changes were most apparent on the headache side of the subsequent attack. Discussion: Subclinical preattack thermal pain hypersensitivity seems to be a feature of the process that leads to a migraine attack.