FIBROMYALGIA AND HEADACHE - FAILURE OF SEROTONERGIC ANALGESIA AND N-METHYL-D-ASPARTATE-MEDIATED NEURONAL PLASTICITY - THEIR COMMON CLUES

A defect in serotonergic analgesia and a hyperalgesic state are propos ed as features common to headache and fibromyalgia. The benefit to bot h migraine and fibromyalgia from inhibiting ionotropic N-methyl-D-aspa rtate receptor activity implies that redundant hyperalgesia-related ne uroplastic changes are crucial for severe or chronic migraine and prim ary fibromyalgia. The fact that migraine and primary fibromyalgia shar e some pivotal set-up of serotonergic and excitatory amino acid system s led us to analyse epidemiological data supporting the hypothesis tha t analgesic disruption and a consequent hyperalgesic state are mechani sms of both migraine and fibromyalgia. Beyond demonstrating the comorb idity between migraine and primary fibromyalgia, the data suggest that migraine may represent a risk factor for fibromyalgia.