A clinical image of migraine. On prevalence, impact of disease, natural course of attacks and influence of 5-HT1B/1D-agonists
The first, large nationwide survey of the epidemiology of migraine in Sweden was performed. The one-year prevalence is 13.2 b1.9% (16.7% among women and 9.5% among men). No more than half of the migraineurs have been diagnosed by a physician, and only 76% of those who believed that they had migraine fulfilled the strict IHS criteria for migraine. In a subsequent postal questionnaire survey, the mean attack frequency was 1.3 per month. Thus the number of attacks per year among Swedish adults is approximately 10 million. The minority of sufferers have the majority of all attacks. The mean attack duration was 19 hours. A considerable number of individuals reported attacks shorter than 4 hours or longer than 72 hours. An extension of the time window 4¡V72 hours may thus be reasonable. Less than half of the individuals recovered completely between the attacks. In spite of this, only every fourth one was a current consulter of a physician. A majority of the migraineurs reported absence from school or work, a negative influence of migraine on the most important factors of life, and an interest in testing other treatments for migraine. There is room for improvement in the management of migraine in Sweden.In the first study designed to prospectively document the natural course of untreated migraine attacks in detail, a new integrated time-intensity method for self-assessment of the key symptoms was tested. There is no simple relationship between the point of time and intensity of symptoms, and the characteristic symptoms usually follow each other in a similar course, which supports the notion of a reciprocal underlying pathophysiological mechanism. Triptan therapy frequently only temporarily distorts the basic pattern of attacks.In a prospective, cross-over study, two attacks were treated with subcutaneous sumatriptan as early as possible and two attacks as late as the patients could bear. No significant differences were found in any efficacy parameter, and a majority of the patients claimed that their medication was equally effective when given early as when given late in the course of the attack. The findings do not support the present paradigm, that migraineurs are less responsive to late treatment as a result of central sensitization. The clinical experience that sumatriptan influences the perception of tactile and thermal stimuli in humans was tested in a randomized, double-blind, placebo-controlled cross-over study. It was found that sumatriptan 6 mg subcutaneously caused allodynia of short duration. This could explain some of the temporary sensory sideeffects of triptans and warrants consideration in the interpretation of studies on migraine-induced allodynia.
Göteborgs universitet/University of Gothenburg
Institute of Clinical Neurosciences
Institutionen för klinisk neurovetenskap
Arvid Carlsson salen, Academicum, Medicinaregatan 3, kl. 09.00
Date of defence