An association between migraine and cutaneous allodynia

Recent animal studies on the mechanism of migraine show that intracranial p ain is accompanied by increased periorbital skin sensitivity. These finding s suggest that the pathophysiology of migraine involves not only irritation of meningeal perivascular pain fibers but also a transient increase in the responsiveness (ie, sensitization) of central pain neurons that process in formation arising from intracranial structures and skin. The purpose of thi s study was to determine whether the increased skin sensitivity observed in animal also develops in humans during migraine attacks, Repeated measureme nts of mechanical and thermal pain thresholds of periorbital and forearm sk in areas in the absence of, and during, migraine attacks enabled us to dete rmine the occurrence of cutaneous allodynia during migraine. Cutaneous allo dynia is pain resulting from a nonnoxious stimulus to normal skin. In 79% o f the patients, migraine was associated with cutaneous allodynia as defined , and in 21% of the patients it was not. The cutaneous allodynia occurred e ither solely within the referred pain area on the ipsilateral head, or with in and outside the ipsilateral head. Cutaneous allodynia in certain well-de fined regions of the skin during migraine is an as yet unreported neurologi cal finding that points to hyperexcitability of a specific central pain pat hway that subserves intracranial sensation.