Abstract
In 1995–96, three independant case-control studies performed, respectively, in France, Denmark and Italy found that migraine was a risk factor for cerebral infarction in young women, with a relative risk of around 3, higher in migraine with aura than in migraine without aura. The French study also showed that the risk was further increased by OCs and by smoking. These results were received with serious concerns by some (in particular family planning associations) and with scepticism by others, based on the potential biases inherent to case control studies.
At a meeting of the IHS executive committee in 1997, the matter was discussed and we discovered that we ourselves, in our practice, had divergent opinions as to the use of OCs in young female migraine sufferers. It was therefore decided by the executive committee to form a task force on this topic, extending it to HRT use, and I was formally asked to chair this task force.
Our group included a panel of migraine specialists, vascular neurologists, epidemiologists, gynaecologists and haematologists. We were able to meet in Paris for the first time on November 20, 1997 and for the last time on December 2, 1999. Our wish would have been to make clear cut evidence-based recommendations. It was however, soon obvious that despite the results of other studies pointing in the same direction, this would be an impossible task in the absence of prospective double-blind randomized trials of OC or of HRT in migraine sufferers. We therefore decided to review separately the available data on the relationships between, first, female hormones, haemostasis, stroke and migraine and, second, between migraine, haemostasis and stroke. A number of more basic general reviews on contraception, menstrual cycle, female hormones and menopause were thought necessary in order to increase the understanding of this highly complex interdisciplinary field of medicine. There are thus 11 articles which form the bulk of the present special issue of Cephalalgia. Since they thoroughly review the presently available evidence, I very much hope that they will be read in depth and that our readers will not just jump on the task force statement.
The final statement which has been approved by the present IHS executive committee in a no way intends to dictate an exclusive course of management or to define a standard of care. It is a mere attempt to suggest strategies for the use of OCs and HRT in migraine sufferers. It is bound to be subject to modifications whenever other studies become available.
I would like to thank all the members of the task force for their so efficient work and for all the fruitful discussions that we had. I am particularly indebted to A. MacGregor and Steve Silberstein for the final redaction of the consensus statement, and I am most grateful to Zeneca France (now Astra Zeneca) for their generous support for the Paris meetings.