| Popis: |
Summary Objective: Recent studies support the role of extracranial perivascular afferents in a substantial percentage of migraineurs. Perivascular afferent fibres of the superficial temporal artery contain peptides, like calcitonin gene-related peptide (CGRP) and substance P (SP). CGRP and SP are considered relevant in the genesis of migraine pain. Capsaicin is an agonist of the transient receptor potential vanilloid type 1. It causes membrane depolarisation of sensory neurons, which release CGRP, SP and other pain peptides; excitation is followed by a refractory state, causing inactivation. Topical capsaicin has been found to be efficacious in several types of neuropathic pain. We attempted to verify whether topical periarterial capsaicin could ameliorate pain in absence of and during a migraine attack. Methods: On 23 migraineurs showing pain at pressure on scalp arteries, we administered topical capsaicin 0.1% or vaseline jelly on painful arteries in absence of migraine attack. In those having pain reduction > 50%, we made the same comparison during a migraine attack. Results: Topical capsaicin caused > 50% reduction of arterial pain in absence of attack in 17/23 patients, as opposed to two with vaseline. During attacks of mild- to moderate-intensity, > 50% improvement was obtained in 11/17 with capsaicin and in one with vaseline. Conclusions: Although referring to a small number of patients, our data show that topical capsaicin may relieve arterial pain in absence of and during a migraine attack in a substantial number of patients experiencing scalp arterial tenderness. More active capsacinoids might be tried in the future and could provide a new method for treating migraine attacks. |
