Medication overuse reinstates conditioned pain modulation in women with migraine

BackgroundThis study investigated the effects of medication overuse and withdrawal on modulation of pain processing in women with migraine. Temporal summation of laser-evoked thermal pain was used to measure the effects of conditioned pain modulation.Methods36 female participants (12 healthy volunteers, 12 with episodic migraine and 12 with medication overuse headache) were included in a two session protocol. Medication overuse headache subjects were also tested three weeks after medication overuse headache withdrawal. Mechanical and laser-evoked thermal pain thresholds were measured on the back of the non-dominant hand where, later, temporal summation of laser-evoked thermal pain to repetitive thermal stimuli was elicited for 30 min, at an intensity producing moderate pain. Between the 10th and 20th minutes, the contralateral foot was immersed into a water bath at a not painful (30℃) or painfully cold (8℃; conditioned pain modulation) temperature.ResultsEpisodic migraine, medication overuse headache and ...